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OPERATION AND SERVICE for 68AC353

1. 17 Liquid Line Service Valve EVAPORATOR 18 Liquid Line Sight Glass 2 19 Shipping Shut off Valves 20 Condenser Coil 21 Receiver 15 22 Refrigerant Sight Glass 23 Fusible Plug 24 Charge Isolation Valve fr 16 11 u 11 18 11 14 O 12 8 COMPRESSOR Figure 1 6 Refrigerant Flow Diagram 10 10 1 11 348 1 11 HEATING CYCLE Heating circuit See Figure 1 6 components furnished by Carrier Transicold include the heater coils and a solenoid operated heatvalve Components furnished by the bus manufacturerinclude auxiliary heater and boost water pump The controller automatically controls the heat valve during the heating and reheat modes to maintain required temperatures inside the bus Engine coolant is circulated through the heating circuit by the engine and an auxiliary boost water pump When the heat valve solenoid is energized the valve will open to allow engine coolantto flow through the heater coil The valve is normally closed so that if a failure occurs the system will be able to cool LEGEND COOLANT HEAT VALVE Normally Closed INLET lt Kc lt SE OUTLET BOOST lt PUMP V LI LI EVAPORATOR AC 353 MAIN ENGINE RADIATOR
2. 4 11 4 15 2 Transferring Compressor 4 12 4 15 3 Shim less Compressor Clutch 4 12 4 15 4 Compressor Oil Level 4 13 4 15 5 Checking Unloader Operation 4 13 4 16 TEMPERATURE SENSOR CHECKOUT 4 13 4 17 PRESSURE TRANSDUCER CHECKOUT 4 14 4 18 REPLACING SENSORS AND TRANSDUCERS 4 14 419 LOGIC BOARD REPLACEMENT 4 15 ELECTRICAL EE precum ex Ra IN D NERA FEE qM MEME EE 5 1 5 1 INTRODUGTION 25 RR xU Ec eique Erde ER EM P 5 1 10 10 iii T 348 LIST OF FIGURES FIGURE NUMBER Page Figure 1 1 System Component Identification 1 3 Figure 1 2 Rooftop Unit Components 1 4 Figure 1 3 Condensing Section Components 1 5 Figure 1 4 Evaporator Section Components 1 6 Figure 1 5 System Air Flow cup x E Ra o
3. Figure 1 7 Heat Flow Diagram T 348 10 10 1 12 CONTROL PANEL WITH GR60 RELAY BOARD Board See Figure 1 10 Fresh Air elay Board GR60 See Figure 1 11 Terminal Block 3 Figure 1 8 Control Panel 10 10 1 13 T 348 1 13 CONTROL PANEL With Out CAN D Fuses Fresh Air Power Terminal Block PTB Terminal Block TB Ground Board See Figure 1 10 Relay Board See Figure 1 12 Logic Board Data Communications See Figure 1 13 Power Relay ON gt Figure 1 9 Control Panel T 348 1 14 10 10 1 14 LOGIC BOARD A B D E F 6 H I J K L M N 0 6 LOWd N gt 8 6510824 N38 3INQOW 01901 11 Logic board power in 17 Diagnostics interface RS 232 DB9 12 Micromate Display interface 18 Notused J3 Manual control inputs D2 Blinks once per second in normal operation J4 Interlock Inputs On steady to indicate alarms detected WTS low side pressure switch etc D3 Off normal operation blinks out alarm J5 Relay board interface codes 2 digits each when alarms detected J6 Sensorinputs Thermistors etc A P Configuration J umpers Figure 1 10 Logic Board 10 10 1 15 T 348 1 15 RELAY BOARD GR60 24VDC K1 K2 K3 K4 K5 K6 K 7 K8 K 9 Energizes evaporator fans 1 amp 2 in high speed or evapo
4. e Service or replace necessary components 4 5 2 Refrigerant Removal From An Inoperative f Leak check ti dreplace filter drier 15 2 2 1 remove the refrigerant from compressor that is not operational do the following g Energize the Liquid Line Solenoid Valve LSV 13 a Attach a manifold gauge set as shown in Figure 4 5 using an external power source 24 VDC and isolate the compressor by front seating the dis charge and suction service valves items 1 amp 6 h Move the suction service hose blue from the com pressor suction service valve to the filter drier outlet b Recover refrigerant with a refrigerant reclaimer If the valve 16 Mid seat the Filter Drier Outlet Valve and discharge service valve port is not accessible it will evacuate the low side of the system to 500 microns be necessary to recover refrigerant through the suc Close off the pump valve 23 and vacuum gauge tion service valve port only valve 22 and Shutthe vacuum pump off Wait5 min C Service or replace components as required and leak utes to verify that vacuum holds check the compressor i Back seat the filter drier outlet valve Re attach the d Using refrigeranthoses designed for vacuum service suction service hose blue to the compressor suction connecta vacuum pump to center connection of man service valve Open the suction service valve 6 and ifold gauge set Evacuat
5. S edi 3 1 3 2 2 AcliVatlon bebo et PC E Eoo aep Po ds 3 1 3 2 3 Alam Queue ue PUE IER Ee pan C ca ep Plor ds 3 1 3 2 4 sta 3 1 3 2 5 Alarm Queue oo eA eoe ve Y Cette ns 3 1 3 3 TROUBEESHOOT ING csi elc a telaque UE DE as 3 1 3 3 1 Troubleshooting No CAN Communication 3 2 3 3 2 System Will Not CO0l 1 EL EE pared A 3 5 3 3 3 System Runs But Has Insufficient Cooling 3 5 3 3 4 Abnormal Pir sSures 4 f eq el SCT eis 3 5 3 3 5 Abnormal Noise Or Vibrations 3 5 3 3 6 Control System 3 6 3 3 7 Evaporator Air Flow Or Restricted Air Flow 3 6 3 3 8 Expansion Valve 3 6 3 3 9 Heating Malfunction isi as aya eae ae Danes u m ba a 3 6 SERVICE a aaa PERLE sc 4 1 41 MAINTENANCE SCHEDULE 4 1 42 OPENING TOP COVER EVAPORATOR 4 1 43 REMOVING TOP COVER
6. 4 7 4 8 2 Adding Full Charge i ieee Ee eek dee ade hiwa RE OR 4 7 4 8 3 Adding Partial Charge 2 2 Beat ed Waa ead Sees 4 7 4 9 CHECKING FOR NONCONDENSIBLES 4 7 4 10 CHECKING AND REPLACING HIGH OR LOW PRESSURE SWITCH 4 8 FILTER DRIER ciate deeg yusa et 4 8 4 11 1 To Check Filter Drier ee EE RE 4 8 4 11 2 Replace Filter sat pana D He Pene 4 8 4 12 SERVICING THE LIQUID LINE SOLENOID VALVE 4 9 4 12 1 Coil Replacement eee A 4 9 4 12 2 Internal Part 7 1 4 9 4 12 3 Replace Entire RR ands RES 4 9 4 13 THERMOSTATIC EXPANSION VALVE 4 10 4 13 Valve Replacement dead ass vase DN 4 10 4 13 2 Superheat Measurement 4 10 4 14 REPLACING EVAPORATOR RETURN AIR FILTERS 4 11 4 15 COMPRESSOR MAINTENANCE 4 11 4 15 1 Removing the Compressor
7. 7 K8 LEGEND DESCRIPTIDN AIR CONDITIONING MANUAL SWITCH AMBIENT TEMPERATURE SENSOR BOOST PUMP SIGNAL CONDENSER FAN RELAY 1 COMPRESSOR CLUTCH COND MOTOR 1 COND MOTOR 2 COND MOTOR 3 COND MOTOR 4 COND MOTOR 5 COND MOTOR 6 COND SPEED RELAY ON HIGH SPEED RELAY OUTPUT ACTIVE RELAY K1 OUTPUT ACTIVE FUSE 1 OPEN FRESH AIR DAMPER FUSE 3 OPEN CEVAPORATOR FAN RELAY K7 OUTPUT ACTIVE RELAY OUTPUT ACTIVE FUSE 9 OPEN CONDENSER FAN FUSE 2 OPEN CUNLDADER 1 FUSE 5 OPEN CUNLDADER 2 gt A C CLUTCH amp LSV OUTPUT ACTIVE UNLDADER 1 OUTPUT ACTIVE UNLDADER 2 OUTPUT ACTIVE FRESH AIR DUTPUT ACTIVE FUSE 6 OPEN CHEAT VALVE HEAT VALVE OUTPUT ACTIVE FAULT OUTPUT ACTIVE FUSE 4 OPEN FAULT LIGHT CIRCULATION PUMP OUTPUT ACTIVE DRIVER LSV ACTIVE OR FLOOR BLOWER ACTIVE FUSE 8 OPEN SPARE FUSE 10 OPEN CIRCULATION PUMP FUSE 7 OPEN COMPRESSOR CLUTCH DISCHARGE PRESSURE TRANSDUCER EVAP MOTOR 1 EVAP MOTOR 2 EVAP MOTOR 3 EVAP MOTOR 4 EVAP MOTOR 5 EVAP MOTOR 6 FRESH AIR MOTOR FRESH AIR INVERTOR FUSE FAR FUSE Uvi FUSE EVAPORATOR FAN FUSE FAULT LIGHT FUSE uve FUSE HEAT VALVE FUSE COMPRESSOR CLUTCH FUSE FLOOR BLOWER SPARE FUSE CONDENSER FAN FUSE 10 BOOSTER PUMP FUSE 11 1 FUSE 12 EM2 FUSE 13 EM3 FUSE 14 EM4 FUSE 15 EMS FUSE 16 ENG FUSE 17 1 FUSE 18 CM2 FUSE 19 CM3 FUSE 20 CM4 FUSE 21 CMS FUSE 22 CM6 FUSE 23 POWER IN LOGIC BDARD J1 HIGH
8. 1 13 CONTROL PANE ic peer ee un MURDER aa upa d laesa 1 14 LOGIC BOARD HERR De De M I RR 1 15 115 RELAY BOARD GR60 24VDC 1 16 1 16 RELAY BOARD 24VDC i u er be en ER Oe diee ERAN 1 18 1 17 LOGIC BOARD DATA COMMUNICATIONS 1 19 118 CONTROL PANEL Diagnostic 1 20 OPERATION au Spouse tee S yasta aere uec an ou ot 2 1 21 STARTING STOPPING AND OPERATING INSTRUCTIONS 2 1 241 1 3Power to Logic BOONE EE 2 1 2 1 2 nec Io huy e be erbe Bc ep eiu Dae o ponis 2 1 2 1 3 Self Test and Diagnostics Check for Errors and or 5 2 1 ZLA STOPPING sia ebbe has ma E RE CE 2 1 10 10 i T 348 TABLE OF CONTENTS Continued PARAGRAPH NUMBER Page 2 2 PRE IRIP INSPEC TON etre ge TEE ENEE bak 2 1 2 37 OPERATION EL sane 2 2 2 3 1 Temperature Controla ani EHE TAFE mU DRE 2 2 2 3 2 Be LEE 2 2 2 3 3 Heating eed bka ts se el Ca 2 2 2 314 BOOSE PUMP 4 2
9. 5 4 2 44 SUCTION AND DISCHARGE SERVICE VALVES 4 2 4 4 1 Installing R 134a Manifold Guage 5 4 3 348 ji 10 10 TABLE OF CONTENTS Continued PARAGRAPH NUMBER Page 45 PUMPING THE SYSTEM DOWN OR REMOVING THE REFRIGERANT CHARGE 4 3 4 5 1 System Pump Down For Low Side Repair 4 3 4 5 2 Refrigerant Removal From An Inoperative Compressor 4 4 4 5 3 Pump Down An Operable Compressor 4 6 4 5 4 Removing Entire System Charge 4 6 4 6 REFRIGERANT LEAK 4 6 47 EVACUATION AND DEHYDRATION 4 6 411 General RR wee 4 6 41 22 DER ce Sad ena Na eke aa 4 6 4 7 3 Procedure for Evacuation and Dehydrating System One Time Evacuation 4 6 4 7 4 Procedure for Evacuation and Dehydrating System Triple Evacuation 4 7 4 8 ADDING REFRIGERANT TO 5 5 4 7 4 8 1 Checking Refrigerant Charge
10. fan relay short and reset has failed replace breaker fuse Evaporator Fan Overload ee fan over Ensure connector is Alarm will be generated load jumper is open plugged in or repair wiring Condenser Fan Overload Condenser fan over Ensure connector is Alarm will be generated load jumper is open plugged in or repair wiring UT NN C S EE Maintenance Alarm 1 The compressor hour Resetthe mainte Alarm will be generated meter is greater than nance hour meter the value in Mainte nance Hour Meter 1 Maintenance Alarm 2 The evaporator hour Resetthe mainte Alarm will be generated meter is greater than nance hour meter the value in Mainte nance Hour Meter 2 Low Pressure Warning Suction pressure low Check cause of low Alarm will be generated enough to energize suction pressure Re fer to section 3 3 4 High Pressure Warning Discharge pressure Check cause of high Alarm will be generated high enough to discharge pressure energize UV2 SE to section Alarm Queue Full All locations of the Record and clear Alarm will be generated alarm queue are cur alarm queue rently full and no more alarms can be saved 348 3 4 10 10 Table 3 3 General System Troubleshooting Procedures INDICATION REFERENCE TROUBLE SECTION 3 3 2 System Will Not Cool Compressor will not run Active system alarm V Belt loose or defective Clutch coil defective Clutch malfunctio
11. Compressor amp Liquid T05 Line Solenoid 106 Unloader Valve 1 On 107 Unbadervave2 On T08 T09 T10 T11 Not Applicable On Reheat Coolant Vale On On Bos T12 T 348 Table 2 5 Parameter Codes CODE CODE NAME DESCRIPTION P1 Return Air This value is the temperature measured by the return air sensor If the sensor Temperature is shorted it will display CL If it is open circuited it will display O P Temperature This value is the outside temperature measured the ambient temperature sensor If the sensor is shorted it will display CL If it is open circuited it will dis play OP P4 Suction Line Not used Temperature P5 Suction Pressure This value is the suction pressure measured by the suction pressure transduc er If the sensor is shorted it will display CL If it is open circuited it will display OP Discharge Pressure This value is the discharge pressure measured by the discharge pressure transducer If the sensor is shorted it will display CL and if it is open circuited it will display OP S uperheat Not used Analog Set Point Not used Temperature A C Control Window is the number of degrees F above setpoint at which the unloaders will be 1 both energized This value can be modified between 0 and 10 degrees F The default value is 1 degree F 10 JA C Control Window This is the number of degrees F above AC c
12. Wy w wj N B Default Displav Tem This value determines what temperature value the driver s displav will show as perature a default When the value is OFF set point temperature is displaved When the value is ON return air temperature is displayed This option is only avail able in logic module software revisions 1 9 and newer and drivers displav soft ware revision 1 3 and newer Otherwise P 35 will not be active and set point temperature will only be displayed as default P40 Enable Hidden Alarm This value determines if alarms A33 and A34 are displayed When the value is OFF alarms A33 and A34 will not be displayed When the value is ON alarms A33 and A34 will be displayed P41 Fresh Air Damper When the value is OFF the fresh air damper will operate 5 F above or below the control set point When the value is ON the fresh air damper will operate 2 F above or below the control set point Defrost Operation This value determines if the defrost switch will override the Micromate control ler If the parameter is ON the defrost switch will initiate unit defrost whenever it senses a need for defrosting the Micromate display will shut off in defrost If the parameter is OFF the Micromate display will continue to operate and over ride the defrost switch 10 10 2 7 T 348 SECTION 3 TROUBLESHOOTING 4A CAUTION Do not under any circumstances attempt to service the microprocessor Should a problem develop with
13. 4 Mechanical interface with movement of plunger which may be caused by a deformed enclosing tube Failure to open may be caused by the following 1 Coil burned outor an open circuit to coil connections 2 Improper voltage 3 Defective plunger or deformed valve body assembly Failure to close may be caused by the following 1 Defective plunger or deformed valve body assembly 2 Foreign material in the valve 4 12 1 Coil Replacement a Itis not necessary to remove the refrigerant charge from the system b Place main battery disconnect switch in OFF position and lock c Disconnect wire leads to coil d Remove coil locking nut and O Ring then the threaded collar e Lift coil from enclosing tube and replace f With the coil installed replace the threaded collar then the O Ring and locking nut g Connect wire leads and test operation 4 12 2 Internal Part Replacement a Perform a low side pump down Refer to paragraph 4 5 1 b Carefully loosen See assemblyandensure no pressure remains within the valve Disassemble valve and replace defective parts c Assemble valve and leak check d Evacuate low side and re open system 10 10 4 12 3 Replace Entire Valve a Perform a low side pump down R efer to paragraph 4 5 1 b Remove coil assembly Refer to paragraph 4 12 1 c Disconnect valve from liquid line and filter drier d Unbolt valve body from frame and remove from unit See Figure 4 9 item
14. c Carrier Transport Air Conditioning Carrier 50 Grumbacher R oad A United Technologies Company York PA 17402 USA Carrier Transicold Division Tel 1 800 673 2431 Carrier Corporation Fax 1 717 764 2219 Transport Air Conditioning Group P O Box 4805 Syracuse 13221 U S A www carrier trans icold com A member of the United Technologies Corporation family Stock symbol UTX TRANSICOLD 2010 Carrier Corporation DP rinted in U S 1010
15. fer to paragraph 1 5 for superheat setting If superheatis not within tolerance replace the valve 4 14 REPLACING EVAPORATOR RETURN AIR FILTERS The evaporator return air filters are located in the evaporator section next to the evaporator coils Access to the filters is accomplished by removing the evaporator covers The filters should be checked for cleanliness periodically depending on operating conditions A dirty filter will restrict air flow over the evaporator coil which may cause insufficient cooling or heating and possible frost buildup on the coil To remove the filters do the following a Place main battery disconnect switch in OFF position and lock b SEH the evaporator top cover Refer to paragraph Grasp and lift the filter elements out using care not to damage the evaporator coil Reverse procedure to install new filters and close the covers 4 15 COMPRESSOR MAINTENANCE 4 15 1 Removing the Compressor compressor is inoperative and the unit still has refrigerant pressure isolate the compressor and remove the refrigerant Refer to paragraph 4 5 2 If compressor is operative perform a pump down Refer to paragraph 4 5 3 a Place main battery disconnect switch in OFF position and lock Tag and disconnect wiring to the high pressure and low pressure switch unloaders and clutch Remove tension on drive belts remove drive belts d Loosen bolts at suction and discharge service valv
16. 1 1 1 3 10 Air Exchange fection rs hayaya ied eke Ee x DLE TEE DEL eh Ix c VERO x 1 1 1 3 11 Controller R EP DX EE ERES 1 1 14 GENERAL DESCRIPTION iiie du ERR hal ERR ERA PE heads a 1 4 1 4 1 Compressor Assemblv 1 4 1 4 2 Discharge Check Valve 2 Ades Wiebke dete tS 1 4 1 4 3 Rooitop eder ER eee Rt a ec go A 1 4 1 4 4 Condensing Section ux orbe l Rame c Ra ted 1 5 145 EvaporatorSection ein dg Ee RE ORE EY Eun ERG 1 6 L p Fresh Air System scene dang REPERI ERR ME EE doe EEN ERU CER RICE ce 1 6 1 4 7 System Operating Controls And Components 1 7 15 REFRIGERATION SYSTEM COMPONENT 1 7 16 ELECTRICAL SPECIFICATIONS MOTORS 1 7 17 ELECTRICAL SPECIFICATIONS SENSORS AND TRANSDUCERS 1 7 1 8 SAFETY DEVIGES bit dac shies obe Eb s dad e ba ea 1 8 1 97 AIRF EOW ua cie ba RR RC Riera FE RU BOE 1 9 1 10 AIR CONDITIONING REFRIGERATION CYCLE 1 10 IGI HEATING CYCLE 221 t dal ed 6 1 12 112 CONTROL PANEL WITH GR60 RELAY BOARD
17. 2 3 10 Liquid Line Solenoid Control The liquid line solenoid is energized open when the compressor clutch is energized and de energized closed when the clutch is not 2 3 11 Alarm Description Alarm descriptions and troubleshooting procedures are provided in section 3 2 3 12 Hour Meters Hour meter readings are available in the parameter code list of the Micromate The hour meters record the compressor run time and the total time the evaporator fans are on The maximum hours are 999 999 Refer to paragraph 2 4 2 for instructions on reading parameter codes 2 4 MICROPROCESSOR DIAGNOSTICS The Micromate control panel allows the user to interface with the microprocessor based control This allows system parameters alarms and settings to be viewed and modified 2 4 1 Control NOTE 1 This procedure should be performed by an HVAC technician who has been trained on Carrier system design The control configuration is preset by the manufacturer and resetting of the parameters should not be required Itis recommended that Carrier Service or Engineering is contacted before any control configuration is changed Carrier can not be responsible for failures or damage resulting from unauthorized changes T 348 2 4 2 lfareplacementLogic Module is installed it is necessary to match the configuration jumpers refer to Figure 1 10 to the original board Refer to paragraph 4 19 a Turn the A C main power switch located in
18. INDICATES A CONNECTOR INDICATES A NORMALLY OPEN CONTACT INDICATES A CONNECTOR WITH PIN LOCATION INDICATES DIODE INDICATES FUSE INDICATES PRESSURE SENSOR INDICATES LED ASSEMBLY INDICATES PRESSURE SWITCH NC INDICATES PRESSURE SWITCH NO INDICATES TEMPERATURE SENSOR INDICATES MANUAL RESET BREAKER INDICATES RELAY COIL INDICATES SWITCH N O INDICATES TEMPERATURE SWITCH NO INDICATES POLY SWITCH INDICATES LAMP INDICATES RIBBON CABLE Figure 5 1 Wiring Schematic Legend PM Motors 68AC353 102 102 4 102 5 5 2 10 10 DEE ADT H iv3H inno ND FE SAL lt Bore m 2211 lem GNONVIS det o B T 348 Control Circuit PM Motors 68AC353 102 102 4 102 5 5 3 2 Wiring Schematic Figure 5 10 10 7 m A EA 4 FLDDR BLDVER SISNAL 24 t9 PUMP SIGNAL 24 VLD 98 63069 Figure 5 3 Wiring Schematic Power Circuit PM Motors 68AC 353 102 102 4 102 5 T 313 5 4 10 10 SYMBDL ACMS ATS BPS CFR1 CL CM1 CM3 CM4 5 6 CSR 16 D17 D18 D26 D30 D31 D38 D47 D51 D54 057 D60 D61 D63 D66 D68 D69 D72 D77 D83 D90 DPT EM1 EM2 EM3 EM4 EM5 EM6 FAM FAI FI Fe F3 F4 FS F6 F7 F9 F10 Fil Fle F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 HPS HSV
19. Worn or broken valves Liquid slugging Insufficient oil Clutch loose rubbing or is defective V belt cracked worn or loose Dirt or debris on fan blades 3 5 REDIR S 4 8 1 Check Check Clean 4 18 See Table 1 3 4 8 Open Check O pen 4 11 4 8 3 3 8 3 3 7 Replace Compressor valve defective See Table 1 3 Check Tighten See Table 1 3 SeeTable 1 3 3 3 8 4 15 4 Check Check Adjust Clean T 348 Table 3 3 General System Troubleshooting Procedures Continued INDICATION REFERENCE TROUBLE POSSIBLE CAUSES SECTION 3 3 5 Abnormal Noise Or Vibrations Continued Condenser or evaporator fans Loose mounting hardware Defective bearings Blade interference Blade missing or broken 3 3 6 Control System Malfunction Will not control Sensor or transducer defective Relay s defective Microprocessor controller malfunction Logic Board J 3 connector unplugged 3 3 7 No Evaporator Air Flow Or Restricted Air Flow Air flow through coil blocked Gal coil Dirty filter No or partial evaporator air flow Motor s defective Motor brushes defective Evaporator fan loose or defective Fan damaged Return air filter dirty Icing of coil Fan relay s defective Safety device open Fan rotation incorrect 3 3 8 Expansion Valve Malfunction Low suction pressure with high superheat Side to side temperature differ ence Warm Coil Low refrigerant charge Wax oil or dirt p
20. JB Boost pump D90 Clutch relay fuse out JC Ribbon Cable Logic Module to Relay D77 Unloader 1 fuse out Board D31 Condenser motor fan relay fuse out c Fuses D83 Boost pump relay fuse out F1 Fresh air relay F2 Unloader 1 relay F3 Evaporator fan motor relay F4 Fault light out relay F5 Unloader 2 relay F6 Heater relay F7 Clutch relay F8 Spare F9 Condenser motor fan relay F10 Boost pump relay Figure 1 12 Relay Board T 348 1 18 10 10 1 17 LOGIC BOARD DATA COMMUNICATIONS loooooooo8 9 15 160000000023 Pin 13 14 15 16 17 18 20 21 22 23 Function RS 232 TXD RS 232 RXD LED Out N C N C RS 232 Gnd N C N C N C N C N C Remarks HVAC Data Port HVAC Data Port Status Indicator O ptional HVAC Data Port Figure 1 13 Logic Board Data Communications Pin Function Remarks 1 24VDC Power In 2 24VDC Return Ground 3 Alt CAN_H CAN Port 2 Optional 4 Alt CAN_L CAN Port 2 Optional 5 N C 6 N C 7 N C 8 LED Gnd Status Indicator O ptional 9 CAN_H J 1939 Port 10 1 J 1939 Port 11 N C 12 N C 10 10 T 348 1 18 CONTROL PANEL Diagnostic Module 1 Display 7 HEAT Only Button 2 DOWN Button decrease selection 8 FAN SPEED Button 3 UP Button increase selection 9 FRESH AIR Button 4 VENT Only Button 10 TEMPERATURE Inside Outside 5 AUTO Button Automatic Control Button 6 COOLING Only Button 11 ON OFF Button Figure
21. ORS hex nuts each side ofthe filter drier Remove the filter drier f Remove seal caps from the new filter drier Apply a el to the O Rings and seatin the grooves of the filter drier Assemble the new filter drier to lines ensuring that the arrow on the body of the filter drier points in the direction of the refrigerant flow refrigerant flows from the receiver to the evaporator and that the O Rings have remained in place Finger tighten 5 hex nuts h Tighten the filter drier ORS hex nuts using two open end wrenches 10 10 i Evacuate the filter drier and lines by connecting a vacuum pump as shown in Figure 4 6 Evacuate to 500 microns Backseat fully close the service valve port and re place valve cap k Test filter drier for leaks Check refrigerant level 4 12 SERVICING THE LIQUID LINE SOLENOID VALVE The Liquid line solenoid valve Figure 4 9 requires no maintenance unless a malfunction to the internal parts or coil occurs This ma be caused by foreign material such as dirt scale or sludge in the refrigeration system or improper voltage to the coil There are only three possible valve malfunctions coil burnout failure to open or failure to close Coil burnout may be caused by the following 1 Improper voltage 2 Continuous over voltage more than 10 or under voltage of more than 15 3 Incomplete magnet circuit due to the omission of the coil housing or plunger
22. R 134a Itmav be necessary to block condenser air flow to raise discharge pressure d Under the above conditions the system i gt propery charged when the white balls are floating and a liquid level is detected in the receiver sight Adjust the charge add or remove to meet this condition 4 8 2 Adding Full Charge a Install manifold gauge set at the compressor suction and discharge service valve ports See figure Figure 4 6 b and dehydrate system R efer to paragraph 10 10 4 7 NOTE Evacuation can be performed at the compres sor but liquid charging should only be done at the charge isolation valve on the bus roof See Figure 4 6 Item 11 or the discharge line ser vice port 5 Figure 4 6 Item 2 c Place appropriate refrigerant cylinder on scales P re pare to charge liquid refrigerant into the system by connecting the charging hose from refrigerant cylin der 20 to the charge isloation valve LL d Energize the Liquid Line Solenoid Valve LLSV 13 using an external power source 24 VDC e Note weight of refrigerant and cylinder f Open cylinder valve 20 and purge hose at charge isolation valve 11 g Midseatfilter drier inlet valve to allow liquid refrigerant to flow into the low side h When correct charge has been added refer to para graph 1 5 close cylinder valve i Remove 24 VDC from Liquid Line Solenoid j Backseat charge isolation valve k Check cha
23. armature plate will eliminate the need for separate shims previously installed on the armature The shim ack has been replaced by three adjusting screws installed on the spring plate of the armature Armature to rotor clearance will SC the same 030 060 but the procedure to adjust will be different from original shim style clutch Clutch assemblies are interchangeable The clearance is factory set on each clutch but should the need arise to adjust the clutch gap the following procedure should be followed Three Point Clutch Adjustment Procedure a Confirm the clutch electrical circuit can not be ener gized while you are working on clutch WARNING Battery disconnect should be off 5 gt b With 045 feeler gauge check the clearance at the three set screws and determine what adjustment needs to be made Clearance is to be 045 015 With a 1 8 hex socket wrench and a 7 16 box wrench to hold the locking nut back off the three set screws until they do not contact the armature plate Turn the set screws CW until they just make contact with the armature plate Adjust clockwise one and one half turns after contact One and one half turns equals approximately 040 10 10 e Measure the initial clearance after the one and one half turns CW and adjust for a clearance between 030 and 060 All three set screw locations should be very close in clearance dimensions f When cl
24. ecm lied bp o s e dex dde 2 3 2 3 5 Tet bayan 2 3 2 3 6 Compressor Unloader 2 3 2 3 7 Evaporator Fan Speed Selection 2 3 2 3 8 Condenser Control eee ee ped dete ER on aioe Ren 2 3 2 3 9 Compressor Clutch Control 2 4 2 3 10 Liquid Line S olenoid Control 25 ved eee e dev able RV DARE 2 4 2 3 11 Alarm Description 2 RR Rem Re Re Rn ed Eu ERR ERA ER haa kah 2 4 2 3 12 Hour Meters etna Ed a e ocio e a ERR ead ee Rn NEE e e RE RR 2 4 24 MICROPROCESSOR DIAGNOSTICS 2 4 2 4 1 Control EE 2 4 2 4 2 Diagnostic et te ee ee 2 4 2 4 3 System P aramelers suru u a ae EE deanna Maat 2 4 2 44 MOdG inv UE ay hee ea Ree ete UR HIR 2 5 TROUBLESHOOTING 3 1 31 SEI IS NES UE 2 puis 3 1 3 2 SYSTEM ALARMS onn g a o da vare dius 3 1 3 2 1 0065 Be hake whale
25. 6 Wiring Schematic Power Circuit Brushless Motors 68AC353 102 1 102 3 102 6 5 7 Figure 5 7 Wiring Schematic Condenser Circuit Brushless Motors 68AC353 102 1 102 3 102 6 5 8 Figure 5 8 Wiring Schematic Evaporator Circuit Brushless Motors 68 353 102 1 102 3 102 6 5 9 Figure 5 9 Wiring Schematic Legend Brushless Motors 68AC353 102 2 5 10 Figure 5 10 Wiring Schematic Control Circuit Brushless Motors 68 353 102 2 5 11 Figure 5 11 Wiring Schematic Control Board Power Circuit Brushless Motors 68 353 102 2 5 0 Figure 5 12 Wiring Schematic Condenser Motor Power Circuit Brushless Motors 68AC353 102 2 5 13 Figure 5 13 Wiring Schematic Evaporator Motor Power Circuit Brushless Motors 68 353 102 2 5 14 T 348 iv 10 10 LIST OF TABLES TABLE NUMBER Page Table 1 1 Option Legend u qasa eel dad had eek edad pad d 1 2 Table 1 2 0 aaa e t ER RU 1 3 Table 1 3 Additional Support Manuals 1 4 2 1 0110 UVE Relay 2 3 aa ad ddan ded dorch Vad dein desch edd 2 3 Table 2 2 Unloader UV2 Relay gm ie pen RELIER AERE Xe IE 2 3 Table 2 3 Evaporator Fan Speed Relay Operation 2 3 Table 2 4 Controller TestLiSE scs de
26. 8 e Install new valve onto frame f Apply a TA coat of oil to the O Rings and connect the liquid line and the filter drier g Leak check connections h Evacuate low side and re open charge isolation valve i Replace coil assembly and test operation 1 Locking Nut 5 Plunger Assembly 2 O Ring 6 O Ring 3 Threaded Collar 7 Body 4 Coil 8 Mount Figure 4 9 Liquid Line Solenoid Valve T 348 4 13 THERMOSTATIC EXPANSION VALVE The thermostatic expansion valve Figure 4 9 is automatic device which maintains constant superheat of the refrigerant gas leaving the evaporator regardless of suction pressure The valve functions are a automatic control of refrigerant flow to match the evaporator load and b prevention of liquid refrigerant entering the compressor Unless the valve is defective it seldom requires any maintenance 1 Power Head 4 Body Assembly 5 ORS Fitting 2 Equalizer Connection 6 O Ring 3 Bulb 7 ORS Adapter Fitting Figure 4 10 Thermostatic Expansion Valve 4 13 1 Valve Replacement a Pump down low side of the unit Refer to paragraph 4 5 1 Remove insulation from expansion valve and bulb See Figure 4 10 and Figure 4 11 Loosen retaining straps holding bulb to suction line and detach bulb from the suction line Loosen nuts equalizer line and disconnect equalizer
27. alarm time will not be shown If the 3 3 TROUBLESHOOTING AUTO key is held down for five seconds while is displayed all inactive alarms are cleared A listing of General procedures for system troubleshooting are alarm codes is provided in Table 3 2 provided in Table 3 3 10 10 3 1 T 348 3 3 1Troubleshooting No CAN Communication Follow these steps 1 Connect the Micromate display unit 2 Check that the parameters are displayed by the Micromate display unit 3 If no parameters are displayed STOP The Micro mate logic unit is bad 4 Use an RS232 USB cable to connect a laptop USB port to the Micromate Logic unit 5 Launch HyperTerminal software by clicking on start All Programs accessories communications H yper Terminal With the Caps Lock set press S and 5 keys in unison then press Enter 7 Withthe Caps Lock set press O and press Enter 8 A stream of five 2 digit numbers starting with 3D should be shown 3D 00 E6 DD 5C 3D 00 FF C441 3D 00 EB D8 35 T 348 3 2 9 If no digits are streamed STOP The Micromate Logic unit or the interface connection is defective 10 Connect the RS232 USB cable to the Gateway RS232 connector 11 following 3 repeating streams should be shown T18FFDD1980000000000000000 T18FFDE 1980000000000000000 T18FFDD19800FF00000000FFFF T18FFDD1980000000000000000 T18F F DE 1980000000000000000 T18FFDD19800FF00000000FFFF 12 1 no
28. amp 2 Fresh air damper Heat valve Fault output and Spare output f Connectors EF1 EF6 Evaporator fans CF1 CF4 Condenser fans 15 Amp JP1 External evaporator amp condenser fan thermal overload connections P2 Logic board connector 1 Boost pump J P4 A C clutch fault output compressor high pressure switch JP5 Spare output fresh air output heat valve JP6 Unloaders 1 amp 2 10 10 g LEDS D2 Relay K1 output active evaporator fans 1 2 3 amp 4 energized D 6 Will be brightly lit if evaporator fans 1 2 3 amp 4 are on high Will be at half intensity of they are on low D14 Relay K3 output active evaporator fans 5 amp 6 energized D17 Will be brightly lit if evaporator fans 5 amp 6 are on high Will be at half intensity of they are on low D26 Relay K7 output active condenser fans 1 2 3 amp 4 energized 030 Will be brightly lit if condenser fans 1 2 3 amp 4 are on high Will be at half intensity of they are on low D38 Relay K9 output active condenser fans 5 amp 6 energized 041 Will be brightly lit if condenser fans 5 6 are high Will be at half intensity of they are on low D51 A C clutch liquid solenoid valve output active D54 Unloader 1 output active D57 Unloader 2 output active D60 Fresh air output active D63 Heat solenoid valve output active D66 A C fault output active D69 Boost pump output active D72 Floor blower output active F
29. damper tto allow addition of fresh air into the air entering the evaporator coil For additional information flow refer to paragraph 1 9 10 10 1 4 7 System Operating Controls And Components The system is operated by a Carrier Transicold Micromax microprocessor controller which consist of a relay board Figure 1 11 logic board Figure 1 10 and manual operator switches The manual operating switches are located on the drivers control and may consist of a single OEM supplied ON OFF switch additional OEM switches or Carrier Transicold supplie Micromate control panel Figure 1 14 The logic board regulates the operational cvcles of the svstem bv energizing or de energizing relavs on the relav board in response to deviations in interior temperature Modes of operation include Cooling Heat and Vent On systems fitted with only an ON OFF switch and on svstems with the Micromate set inthe AUTO mode the logic board will cycle the system between the operating modes as required to maintain desired set point temperature In the vent mode the evaporator fans are operated to circulate air in the bus interior In the heat mode the heat valve is opened to allow a flow of engine coolant through the heat coils of the evaporator coil The evaporator fans operate to circulate air over the evaporator coil in the same manner as the vent mode In the cooling mode the compressor is energized while the evaporator and c
30. injury or death 4A WARNING Indicates hazards or unsafe conditions which COULD result in severe personal injurv or death CAUTION potential hazards unsafe practices which COULD result in minor personal injury product property amage 10 10 Safety 1 T 348 SPECIFIC WARNING AND CAUTION STATEMENTS The statements listed below are applicable to the refrigeration unit and appear elsewhere in this manual These ee precautions must be understood and applied during operation maintenance the equipment covered herein SPECIFIC WARNINGS AND CAUTIONS 4A WARNING Be sure to observe warnings listed in the safety summary in the front of this manual before performing maintenance on the hvac system 4A WARNING Read the entire procedure before beginning work Park the coach on a level surface with parking brake applied Turn main electrical disconnect switch to the off position 44 WARNING Do not use a nitrogen cylinder without a pressure regulator 4A WARNING Do not use oxygen in or near a refrigeration system as an explosion may occur WARNING The filter drier may contain liquid refrigerant Slowly loosen the ORS hex nuts to avoid refrigerant contact with exposed skin or eyes 4A WARNING Battery disconnect should be off WARNING Extreme care must be taken to ensure thatall the refrigerant has been removed from the compressor crankcase or the resultant pressure will forcibl
31. is accomplished by energizing the compressor and condenser fans opening the liquid line solenoid valve and closing the heating valve Once interior temperature reaches the desired set point the system may operate in the clutch cycle or reheat mode Selection of clutch cycle or reheat is factory programmed in accordance with the bus purchase specification T 348 2 2 A controller programmed for clutch cycle will de energize the compressor clutch and allow the system to operate in the vent mode until further cooling is required A controller programmed for reheat will maintain compressor operation and cycle the heat valve to allow reheating of the return air In the reheat mode interior temperature is maintained atthe desired set point while additional dehumidification takes place 2 3 3 Heating Mode In the heat mode the liquid line solenoid is closed and the compressor and condenser fans are shut down The heat valve is opened to allow a flow of engine coolant through the heat section of the evaporator coil The evaporator fans speed is varied as required to circulate 10 10 air over the evaporator coil based on the temperature difference from setpoint Operation in the heating mode is controlled by the water temperature switch WTS The WTS is located on the engine block of the vehicle is provided by the OEM It senses the engine coolant temperature and reverses its contacts on temperature rise at 105 F The switch pre
32. line from the expansion valve Using two open end wrenches slowly crack open the ORS hex nuts on each side of the valve assembly Remove the valve assembly from the unit Remove the adapter fittings from the valve and install the fittings on the new valve using care to oil and in stall new O Rings Reinstall the valve assembly into the unit again tak ing care to oil and install new O Rings Fasten equalizer line to the expansion valve Leak check the new valve and evacuate dehy drate low side Refer to paragraph 4 5 1 j The thermal bulb is installed below the center of the suction line four or eight o clock position This area must be clean to ensure positive bulb contact Strap thermal bulb to suction line Ensure that retaining straps are tight and renew insulation gt T 348 4 10 required add vapor refrigerant to bring low side pressure to 20 to 30 PSIG R 134a Open filter drier inlet service valve and compressor service val ves l the coach for approximately 30 minutes on fast idle m Check refrigerant level Refer to paragraph 4 8 1 n Check superheat R efer to paragraph 4 13 2 4 13 2 Superheat Measurement NOTE All readings must be taken from the TXV bulb location and out of the direct air stream 1 Suction Line section view 2 TXV Bulb Clamp 3 Nut amp Bolt clamp 4 Thermocouple 5 TXV Bulb Shown in the 4 clock position Figure 4 11
33. the driv er s area to OFF b Connect the Micromate control panel to the service port J 2 located in the return air section refer to Figure 1 10 c Unplug the logic board connector J 3 d Turn the A C main power switch back to the ON posi tion e Activate the system by pressing the 1 0 key on the Mi cromate panel NOTE Be sure to reconnect J 3 when testing is com pleted orthe system will fail to operate when the Micromate is disconnected NOTE When modifying the setpoint temperature for diagnostic purposes be sure to reset the set point when testing is complete 2 4 2 Diagnostic Mode The diagnostic mode can be entered by pressing the UP and DOWN arrow keys simultaneously for 3 seconds The Micromate control panel display screen will go blank for one second and then enter the alarm screen The diagnostic mode allows alarms and system parameters to be viewed Ifthere are any alarms stored the most recent alarm will be shown To exit the diagnostic mode press the ON OFF key once or do not touch any keys for 30 seconds To view additional alarm information refer to section 3 2 4 3 System Parameters To view system parameters first enter the Diagnostic Mode Refer to paragraph 2 4 2 The parameters are shown in Table 2 5 While in the diagnostic mode press an UP or DOWN arrow key to switch the display to the Parameter Display With the first Parameter displayed press the DOWN arrow key to scroll throu
34. the microprocessor replace it 3 1 SELF DIAGNOSTICS that the Logic Board STATUS and CODE LEDs see A self test is performed by the Micromax Logic Board Figure 1 10 flash simultaneously The Micromate each time the board is powered up Errors if any will be control panel display will indicate errors with the code indicated and the unit will not be allowed to start The se where is the error prefix and 15 the error error codes can be read by counting the number of times number Table 3 1 Error Codes CODE WANE DESCRIPTION Data Memory Logic board data memory failure Program Memory Logic board program memory failure Communication F ailure Failure in communication between the logic board and MDST and are Program Memory Display program memory failure 3 2 SYSTEM ALARMS 3 2 2 Activation When alarms are detected they are placed in an alarm Mam Cades queue in the order at which they initiated unless the The Micromax Logic Board continuously monitors alarm is already present Each alarm recorded will also system parameters and will generate an ALARM if a capture an evaporator hour meter reading parameter exceeds preset limits Alarms are indicated corresponding to the activation time If the AUTO key is and the controller will respond in accordance with the pressed while an alarm is displayed the activation time provided ne TE slam SE can capture will be shown e read by counting the number of times th
35. valve that opens with the flow of refrigerant from the compressor When the compressor clutch is disengaged the discharge check valve will close preventing the flow of high pressure liquid from the condenser back into the compressor 1 4 3 Rooftop Unit The Rooftop unit see Figure 1 2 is comprised of the condensing section evaporator section Micromax electronics and the Fresh Air System All components are accessible by lifting the condenser and evaporator top covers Descriptions of the systems are provided in the following sub paragraphs 1 Top Cover Condenser 2 Top Cover Evaporator 3 Condenser Section See Figure 1 3 4 Evaporator Section See Figure 1 4 5 Hinge Evaporator Cover 6 Condenser Fan Grille Figure 1 2 Rooftop Unit Components 348 10 10 14 4 Condensing Section The condensing section Figure 1 3 includes the cover left and right condenser coils fan and motor assemblies receiver service valves and an ambient temperature sensor High pressure high temperature refrigerant gas from the compressor passes thru the shipping shut off valves to the condenser coils The condenser coils provide heat transfer surface for condensing refrigerant gas at a high temperature and pressure The condenser fans circulate ambient air across the outside of the condenser tubes at a temperature lower than refrigerant circulating inside the PID Model Serial Number Tag Coil Assembly Receiver Char
36. 1 14 Micromate Control Panel T 348 1 20 10 10 SECTION 2 OPERATION 2 1 STARTING STOPPING AND OPERATING INSTRUCTIONS 2 1 1 Power to Logic Board Before starting electrical power must be available from the bus power supply The system components receive power from two sources 24 vdc power for the microprocessor electronics is supplied through the bus interface 24 vdc 125 amp power from a circuit breaker in the battery compartment supplies power for the clutch compressor unloader solenoids evaporator and condenser assemblies this power is controlled by the Logic Board 2 1 2 Starting a If the engine is not running start the engine b OEM SUPPLIED SWITCHES Actual start sequence depends on the trols supplied If only an ON OFF switch is supplied placing the switch inthe O N position will startthe sys tem c MICROMATE CONTROL PANEL It 0695989 the system be started the automatic mode 1 The Micromate Control Panel Display see Figure 1 14 may be programmed to display the set point temperature or return air temperature To de termine which display temperature is programmed press the TEMPERATURE button so that the OUT SIDE AIR indicator is illuminated If the controller cycles back to the INSIDE AIR indicator then the controller is programmed to display return air tem perature If the controller does not automatically cycle back to the return air indicator then the control ler
37. 10 psig 23 81 0 68bar Closes at 250 10 psig 13 61 0 68bar e Low Pressure Switch LPS Opens at 3psig 0 41 0 20 bar Closes at 25 3 psig 1 7 0 20 bar f Water Temperature Switch WTS Bus manufacturer supplied suggested close on temperature rise at 105 F 41 16 ELECTRICAL SPECIFICATIONS MOTORS a Evaporator Fan Motor Permanent Magnet 24 VDC Horsepower kW 0 53 0 39 0 4 0 3 Evaporator Motor Full Load Amps FLA Rema Speed 3830 3013 Bearing Lubrication Factory Lubricated additional grease not required b Condenser Fan Motor Permanent Magnet 24 VDC Horsepower kW 0 24 0 18 0 25 0 20 Condenser Motor Full Load Amps FLA Operating Speed RPM 2840 1900 Bearing Lubrication Factory Lubricated additional grease not required 1 7 ELECTRICAL SPECIFICATIONS SENSORS AND TRANSDUCERS a Suction and Discharge Pressure Transducer Supply Voltage 4 5 to 5 5 vdc 5 vdc nominal Supply current 8 mA maximum Output Range 8K ohms minimum Input Range 6 7 to 450 psig 0 46 to 30 62 bar Output Current 1 5 mA minimum to 1 5 mA maximum Output Voltage vdc 0 0098 x psig 0 4659 b Temperature Sensors Input Range 52 6 to 158 F 47 to 70 C Output NTC 10K ohms at 77 F 25 C T 348 18 SAFETY DEVICES System components are protected from damage caused by unsafe operating conditions with safety devices Safety devices with Carrier Transicold supplied equipme
38. 13 6 29 2 45 6 62 9 81 1 10 10 SECTION 5 ELECTRICAL 5 1 INTRODUCTION This section includes electrical wiring schematics covering the models listed in Table 1 2 For applications with supplied operating switches the switches are wired to the Logic Board connector J 3 as shown For units with a Micromate control panel as the operators control there is no wiring to the Logic Board J 3 connector instead the Micromate control panelis hard wired to the Logic Board connector J 2 When the micromate control panelis used for service or diagnostic purposes itis wired in the same manner as shown for drivers panel use thru the optional Service Port Contact your Carrier Transicold service representative or call the technical hot line at 800 450 2211 for questions related to the schematic for your specific model 10 10 5 1 T 348 T 313 LEGEND ATS BPS CR CB4 CBS CB6 7 CB8 CB9 CB10 11 CB13 CF1 CFe CF3 CF6 CL D2 D6 D14 D17 DESCRIPTION AMBIENT TEMPERATURE SENSOR BOOST PUMP SIGNAL CIRCUIT BREAKER CIRCUIT BREAKER EF1 CIRCUIT BREAKER EF2 CIRCUIT BREAKER EF3 CIRCUIT BREAKER EF4 CIRCUIT BREAKER EFS CIRCUIT BREAKER 6 CIRCUIT BREAKER CF1 CIRCUIT BREAKER CF2 CIRCUIT BREAKER CF3 CIRCUIT BREAKER CF4 CIRCUIT BREAKER CFS CIRCUIT BREAKER CF6 CIRCUIT BREAKER MISC COND MOTOR 1 COND MOTOR 2 COND MOTOR 3 COND MOTOR 4 COND MOTOR 5 CO
39. 4 6 Service Connections SINNER Nd acer asa UR BOR RR ADR eee e 4 5 Figure 4 7 Checking High Pressure Switch 4 8 Figure 4 8 Filter Drier 4 8 Figure 4 9 Liquid Line Solenoid Valve 4 9 Figure 4 10 Thermostatic Expansion 4 10 Figure 4 11 Thermostatic Expansion Valve Bulb and Thermocouple 4 10 Figure 4 12 Compressor iu uus ce ead Vea Senet dead eR d e 4 11 Figure 4 13 Removing Bypass Piston 4 11 Figure 4 14 Compressor Clutch 4 12 Figure 4 15 Transducer Terminal Location 4 14 Figure 5 1 Wiring Schematic Legend PM Motors 68 353 102 102 4 102 5 5 2 Figure 5 2 Wiring S chematic Control Circuit PM Motors 68 353 102 102 4 102 5 5 3 Figure 5 3 Wiring S chematic Power Circuit PM Motors 68 353 102 102 4 102 5 5 4 Figure 5 4 Wiring Schematic Legend Brushless Motors 68AC353 102 1 102 3 102 6 5 5 Figure 5 5 Wiring Schematic Control Circuit Brushless Motors 68 353 102 1 102 3 102 6 5 6 Figure 5
40. 6 98 Control Circuit Brushless Motors 68AC353 102 2 Wiring Schematic 10 Figure 5 T 348 5 11 10 10 5 93 335 03345 OL I S 93 335 03395 OL mi 12 00299 03 OPEN P RISE 365810 CLOSE T 280310 _ BOOST PUMP SIGNAL 24 VLT AC FAULT LIGHT cue 24 98 63116 Figure 5 11 Wiring Schematic Control Board Power Circuit Brushless Motors 68AC353 102 2 T 313 5 12 10 10 Condenser Motor Power Circuit Brushless Motors 68AC353 102 2 12 Wiring Schematic Figure 5 T 348 5 13 10 10 26 919 So as SS o 4 4 1 68 353 102 2 Motor Power Brushless Motors 13 Wiring Schematic Figure 5 10 10 5 14 T 313 A Air Filter 4 11 AIR FLOW 1 9 Alarm 2 4 3 1 Alarm Clear 3 1 Alarm Codes 3 1 Alarm Queue 3 1 Ambient Lockout 1 8 Boost P ump 2 3 C Circuit Breaker 1 8 1 17 Clutch 2 4 4 12 Compressor 1 4 1 7 4 11 Condenser Fan 1 7 2 3 Condensing Section 1 5 CONFIGURATION IDENTIFICATION 1 1 Control Panel 1 20 Cooling Mode 2 2 D DESCRIPTION 1 1 Diagnostics 2 1 2 4 Discharge Check Valve 1 4 Discharge Pressure 2 3 Evacuation 4 6 Evacuation One Time 4 6 Evacuation Triple 4 7 Evaporator Fan 1 7 2 3 Evaporator Section 1 6 Exit Alarm Queue 3 1 10 10 INDEX F Fi
41. 8AC 353 condensers are all fitted with a condenser coil a receiver with sight glasses and fusible plug a charge isolation valve and interconnecting tubing 1 3 5 Evaporator Skins Kit The evaporator section may be fitted with one of two different cover assemblies dependent upon the curvature of the bus roof The assemblies available are identified as the 10 M radius cover and the 6 5 M radius cover 1 3 6 Evaporator Blower Kit The 68AC 353 evaporator kits are available with either 4 or 6 blowers with either permanent magnetor brushless motors 1 3 7 Evaporator Connection Kit S D The evaporator units are assembled to allow orientation of the connections for different mounting arrangements and may be supplied with various refrigerant piping layouts for specific applications 1 3 8 Evaporator Connection Kit Indash The evaporator units are assembled to allow connections for various refrigerant piping layouts for remote evaporators 1 3 9 Evaporator Connection Kit Heating The evaporator units are assembled to allow orientation ofthe connections for different mounting arrangements and may be supplied with various engine coolant piping layouts for specific heating applications 1 3 10 Air Exchange Kit The unitwill be fitted with a fresh airexchange assembly air exchange blank off plate Fresh air exchange assemblies may be of the 25 or 50 opening 1 3 11 Controller Kit The Micromax Controller operates the
42. ANUAL SWITCH AMBIENT TEMPERATURE SENSOR BOOST PUMP SIGNAL CDNDENSER FAN RELAY 1 COMPRESSOR CLUTCH COND MOTOR COND MOTOR COND MOTOR COND MOTOR COND MOTOR COND MOTOR 6 COND SPEED RELAY DN HIGH SPEED RELAY Ke OUTPUT ACTIVE RELAY OUTPUT ACTIVE FUSE 1 OPEN FRESH AIR DAMPER FUSE 3 OPEN CEVAPDRATDR FAN RELAY K7 DUTPUT ACTIVE RELAY OUTPUT ACTIVE FUSE 9 OPEN CONDENSER FAND FUSE 2 OPEN CUNLDADER 81 FUSE 5 OPEN CUNLDADER 82 A C CLUTCH LSV DUTPUT ACTIVE UNLDADER 1 DUTPUT ACTIVE UNLDADER 2 DUTPUT ACTIVE FRESH AIR DUTPUT ACTIVE FUSE 6 OPEN CHEAT VALVE HEAT VALVE OUTPUT ACTIVE FAULT DUTPUT ACTIVE FUSE 4 OPEN FAULT LIGHT CIRCULATION PUMP DUTPUT ACTIVE DRIVER LSV ACTIVE OR FLOOR BLOWER ACTIVE FUSE 8 OPEN SPARE FUSE 10 DPEN CCIRCULATIDN PUMP FUSE 7 OPEN COMPRESSOR CLUTCH DISCHARGE PRESSURE TRANSDUCER EVAP MOTOR 1 EVAP MOTOR 2 EVAP MOTOR 3 EVAP MOTOR 4 EVAP MOTOR 5 EVAP MOTOR 6 FRESH AIR MOTOR FRESH AIR INVERTOR FUSE FAR UV1 EVAPORATOR FAN FAULT LIGHT U HEAT VALVE CDMPRESSDR CLUTCH FLOOR BLOWER SPARE 9 CONDENSER FAN 10 BOOSTER PUMP 11 12 13 EM3 14 EM4 15 EMS 16 EM6 17 1 18 CM2 19 CM3 20 CM4 21 CMS 22 CM6 23 POWER IN LOGIC BOARD J1 PRESSUSE SWITCH SOLENOID VALVE ENERGIZES EVAP RELAY EFR1 ENERGIZES EFR LOW SPEED ENERGIZES CFR1 ENERGIZES CSR NDT USED CLUTCH RELAY UV1 RELAY UV2 RELAY FRESH AIR RELAY FAR HEAT RELAY FAULT RELAY BOOST RELAY
43. C353 102 1 102 3 102 6 10 10 5 5 T 348 CSTNISNI saan NOILVYNOIINGS 21901 4442 10 98 00 21 qavod Avd 91 26E00 2T 3906 3190 98 63098 Control Circuit Brushless Motors CAN 68AC353 102 1 102 3 102 6 5 Wiring Schematic Figure 5 10 10 5 6 T 313 STUD FLOOR BLOWER SIGNAL __ 24 VLD a 118 2 C11 FAULT LIGHT iC 24 VOLD 98 63098 Figure 5 6 Wiring Schematic Power Circuit Brushless Motors CAN 68AC353 102 1 102 3 102 6 10 10 5 7 T 348 LT 27 TA lt zs L ETX g pM 9 9 81 6 lt lt 9 6 6 1 o 253 ing gr lt 5 1 lt T TEWX 02 2 Ke GINN 9 0 2 61 da E 6 1 6 TW ar 6 2 818 A 2 ZIWX Q 98 63098 Figure 5 7 Wiring Schematic Condenser Circuit Brushless Motors CAN 68AC353 102 1 102 3 102 6 10 10 5 8 T 313 ADLVADHVAJ 81 cap 336 Figure 5 8 Wiring Schematic Evaporator SS Motors CAN 68AC353 102 1 102 3 T 348 5 9 10 10 T 313 SYMBDL ACMS ATS BPS CFR1 CL CM1 CM3 CM4 CMS CM6 CSR D2 16 017 118 126 130 131 138 147 151 154 157 160 161 LEGEND DESCRIPTIDN AIR CONDITIONING M
44. FLOOR HEAT RELAY LIQUID SOLENOID VALVE LOW PRESSURE SWITCH POWER RELAY POWER TERMINAL BLOCK 1 PDS POWER TERMINAL BLOCK 2 NEG POWER TERMINAL BLOCK POS POWER TERMINAL BLOCK 4 RELAY POWER STUD PDS RELAY POWER STUD RETURN AIR SENSOR SUCTION PRESSURE TRANSDUCER TERMINAL BLOCK TERMINAL 1 TERMINAL BLOCK TERMINAL 2 TERMINAL BLOCK TERMINAL 32 TERMINAL BLOCK TERMINAL 4 ND USED UNLDADER VALVE 1 UNLDADER VALVE 2 WATER TEMPERATURE SWITCH O f 5 2 SYMBOLS INDICATES CONNECTOR TERMINAL INDICATES GROUND INDICATES A WIRE INDICATES A WIRE DEM SUPPLIED INDICATES GROUND STUD CONNECTION INDICATES POWER STUD INDICATES A CONNECTOR INDICATES A NORMALLY OPEN CONTACT INDICATES A CONNECTOR WITH PIN LOCATION INDICATES DIODE INDICATES FUSE INDICATES PRESSURE SENSOR INDICATES LED ASSEMBLY INDICATES PRESSURE SWITCH NC INDICATES TEMPERATURE SENSOR INDICATES MANUAL RESET BREAKER INDICATES RELAY COIL INDICATES SWITCH 0 INDICATES TEMPERATURE SWITCH ND INDICATES LAMP INDICATES POLY SWITCH INDICATES RIBBON CABLE 98 63116 Figure 5 9 Wiring Schematic Legend Brushless Motors 68AC353 102 2 5 10 10 10 1 Gu NOILVYNOIINOO avoa 21901 KT 91 26E00 21 208 21901 90031900 331508334 3 1 3 1N3A 7009 KNUISN3A aw LS 14 1 TINY e 6311
45. ND MOTOR 6 COMPRESSOR CLUTCH EF1 2 LED ASSEMBLY EF3 4 LED ASSEMBLY EFS LED ASSEMBLY EF6 LED ASSEMBLY CF1 2 LED ASSEMBLY CF3 4 LED ASSEMBLY CF5 LED ASSEMBLY CF6 LED ASSEMBLY CLUTCH LED ASSEMBLY UV1 LED OUTPUT ACTIVE UVe LED OUTPUT ACTIVE FRESH AIR VALVE LED OUTPUT ACTIVE HSV LED OUTPUT ACTIVE ALARM LED OUTPUT ACTIVE BOOST PUMP OUTPUT ACTIVE FLOOR BLOWER OUTPUT ACTIVE DISCHARGE PRESSURE TRANSDUCER EVAP MOTOR 1 EVAP MOTOR 2 EVAP MOTOR 3 EVAP MOTOR 4 EVAP MOTOR 5 EVAP MOTOR 6 FUSE 22 POWER IN LOGIC BOARD FRESH AIR INVERTOR FRESH AIR MOTOR FREEZE TEMPERATURE SENSOR NUT USED HIGH PRESSURE SWITCH HEAT SOLENOID VALVE EF 1 2 RELAY EF3 4 REALY EFS RELAY EF6 RELAY EF HIGH RELAY EF 5 6 HIGH RELAY CF1 2 RELAY CF3 4 RELAY CFS RELAY CF6 RELAY CF 1 2 3 4 RELAY LOW SPEED CF 5 6 RELAY LOW SPEED CLUTCH RELAY UV1 R Ar UV2 RELAY FRESH AIR RELAY HEAT RELAY FAULT RELAY BOOST RELAY SPARE RELAY FAN HIGH RELAY EVAP FAN LOW RELAY COND FAN HIGH RELAY COND FAN LOW RELAY LOW PRESSURE SWITCH LIQUID SOLENOID VALVE POWER TERMINAL BLOCK 1 POS POWER TERMINAL BLOCK 2 RETURN AIR SENSOR SUCTION PRESSURE TRANSDUCER UNLOADER SOLENOID VALVE 1 UNLOADER SOLENOID VALVE 2 WATER TEMPERATURE SWITCH SYMBOLS INDICATES CONNECTOR TERMINAL INDICATES GROUND INDICATES A WIRE INDICATES AN SUPPLIED WIRE OR OPTION INDICATES GROUND STUD CONNECTION INDICATES POWER STUD
46. PRESSUSE SWITCH HEAT SOLENOID VALVE ENERGIZES EVAP RELAY EFR1 ENERGIZES EFR LOW SPEED ENERGIZES CFR1 ENERGIZES CSR NDT USED CLUTCH RELAY UV1 RELAY RELAY FRESH AIR RELAY FAR HEAT RELAY FAULT RELAY BOOST RELAY FLOOR HEAT RELAY LIQUID SOLENOID VALVE LDW PRESSURE SWITCH POWER RELAY POWER TERMINAL BLOCK 1 PDS POWER TERMINAL BLOCK 2 POWER TERMINAL BLOCK 3 POS POWER TERMINAL BLOCK 4 RELAY POWER STUD PDS RELAY POWER STUD NEG RETURN AIR SENSOR SUCTION PRESSURE TRANSDUCER TERMINAL BLOCK TERMINAL 12 TERMINAL BLOCK TERMINAL 22 TERMINAL BLOCK TERMINAL 3 TERMINAL BLOCK TERMINAL 4 ND USED UNLDADER VALVE 1 UNLDADER VALVE 2 WATER TEMPERATURE SWITCH 30204846 2414 N N 7 5 5 SYMBOLS INDICATES CONNECTOR TERMINAL INDICATES GROUND INDICATES A WIRE INDICATES A WIRE DEM SUPPLIED INDICATES GROUND STUD CONNECTION INDICATES POWER STUD INDICATES A CONNECTOR INDICATES A NORMALLY OPEN CONTACT INDICATES A CONNECTOR WITH PIN LOCATION INDICATES DIODE INDICATES FUSE INDICATES PRESSURE SENSOR INDICATES LED ASSEMBLY INDICATES PRESSURE SWITCH NC INDICATES TEMPERATURE SENSOR INDICATES MANUAL RESET BREAKER INDICATES RELAY INDICATES SWITCH N O INDICATES TEMPERATURE SWITCH NO INDICATES INDICATES POLY SWITCH INDICATES RIBBON CABLE 98 63098 Figure 5 4 Wiring Schematic Legend Brushless Motors CAN 68A
47. Ree de E WERE Ae eee sana dE 2 5 Table 2 5 Parameter Codes insu ae Sika Rade eae Ra P eie 2 6 Table x3sE Error Codes cott ase e kasa EE 3 1 Table 3 2 Alamm Codes u cem ee epe evan da 3 3 Table 3 3 General System Troubleshooting Procedures 3 5 Table 4 1 Temperature Sensor Resistance 4 14 Table 4 2 Pressure Transducer Voltage 4 15 Table 4 3 Logic Board Configuration 4 15 Table 4 4 R 134a Temperature Pressure 4 16 10 10 T 348 SAFETY SUMMARY GENERAL SAFETY NOTICES The following general safety notices supplement the specific warnings and cautions appearing elsewhere in this manual They are recommended precautions thatmustbe understood and applied during operation and maintenance ofthe equipment covered herein A listing of the specific warnings and cautions appearing elsewhere in the manual follows the general safety notices FIRST AID Aninjury no matter how slight should never go unattended Always obtain first aid or medical attention immediately OPERATING PRECAUTIONS Always wear safety glasses Keep hands clothing and tools clear of the eva
48. Thermostatic Expansion Valve Bulb and Thermocouple Remove Presstite insulation from expansion valve bulb and suction line Loosen T XV bulb clamp and make sure area un der clamp is clean Place temperature thermocouple in contact with the suction tube and parallel to the TXV bulb and then secure loosened clamp making sure both bulb and thermocouple are firmly secured to suction line See Figure 4 11 Reinstall insulation around the bulb Connect an accurate low to the low pressure port Figure 1 6 Start bus and run on fast idle until unit has stabilized about 20 to 30 minutes NOTE When conducting this test the suction pressure must be at least 6 psig 0 41 bar below the ex pansion valve maximum operating pressure MOP Refer to paragraph 1 5 for MOP o Fromthetemperature pressure chart Table 4 4 de termine the saturation temperature corresponding to the evaporator outlet pressure Note the temperature ofthe suction gas atthe expan sion valve bulb Subtract the saturation temperature from this temperature The difference is the super heat of the suction gas The superheat may cycle from a low to high reading Monitorthe superheattaking readings every 3 5 min utes for a total of 5 6 readings Calculate the super heats add the readings and divide by the number of 5 10 10 readings taken to determine average superheat
49. Transport Air Conditioning OPERATION AND SERVICE for 68AC353 102 MICROMAX Rooftop Air Conditioning Unit T 348 10 10 TRANSICOLD o OPERATION AND SERVICE MANUAL TRANSPORT AIR CONDITIONING UNIT MODEL 68AC353 102 ROOFTOP AIR CONDITIONING SYSTEM TABLE OF CONTENTS PARAGRAPH NUMBER Page SAFETY SUMMARY EEN Yan EE ae ate due Fa o Safety 1 DESCRIPTION ususin Duy EE 1 1 11 TINTRODUCTION asa eb hid aa or kad due b 1 1 12 CONFIGURATION IDENTIFICATION 1 1 1 3 lt OPTION DESCRIPTION Seia Tere APIS 1 1 1 3 T sCondenserCover 5 wise PIE ad dr epe eap DRE 1 1 13 2 Condenser Electrical KE ege i RE CREME MERE REEL 1 1 1 3 3 CondenserFan A eR Facer ee d e 1 1 1 3 4 Condenser Refrigeration Kit 1 1 1 3 5 Evaporator Skins KIE y elo ur ER NRI f 1 1 1 3 6 Evaporator Blower Mit ERI ER UI EUER ON E ERE De 1 1 1 3 7 Evaporator Connection Kit S D 1 1 1 3 8 Evaporator Connection Kit Indash 1 1 1 3 9 Evaporator Connection Kit Heating
50. agraph 4 7 3 should take place aftera minorsystem repair replacement of a solenoid valve or a filter drier 4 7 2 Preparation o D 5 Using compound gauge for determination of vacuum level is not recommended because of its inherent inaccuracy a Evacuate and onlyafterpressure leaktest Refer to paragraph 4 6 b Essential tools to properly evacuate and dehydrate anyssystem include a good vacuum pump with a mini mum of 6 cfm 10 2 m hr volume displacement CTD P N 07 00176 11 and a good vacuum indica tor CTD P N 07 00414 00 c Keep the ambient temperature above 60 F 15 6 C to speed evaporation of moisture If ambient temper ature is lower than 60 F 15 6 C ice may form be fore moisture removal is complete 4 7 3 Procedure for Evacuation and Dehydrating System One Time Evacuation a Remove refrigerant using a refrigerant recovery sys tem Refer to paragraph 4 5 4 b The recommended method is connecting lines re frigerant hoses designed for vacuum service as shown in Figure 4 6 c Energize the Liquid Line Solenoid Valve LSV 13 using an external power source 24 VDC d Start vacuum pump Slowly valves halfway then open vacuum gauge valve items 22 amp 23 10 10 e Evacuate unit until vacuum gauge indicates 500 mi crons Hg vacuum f Close off pump valve 23 and stop pump Wait five minutes to see if vacuum holds g Re
51. arge Pressure Transducer 15 4 Discharge Check Valve 16 5 High Pressure Switch 17 6 Service Port Suction Service Valve 18 7 Suction Pressure Transducer 19 8 Low Pressure Switch to crankcase 20 9 Dash Air Liquid Tee Optional 21 10 Dash Air Suction Tee Optional 22 11 Charge Isolation Valve 23 12 Thermal Expansion Valve Figure 4 6 Service Connections 10 10 4 5 Liquid Line Solenoid Valve Liquid Line S ightglass Filter Drier Filter Drier Outlet Service King Valve Manifold Gauge Set Vacuum Pump Reclaimer Refrigerant Cylinder Thermistor Vacuum Gauge Vacuum Gauge Isolation Valve Vacuum Pump Isolation Valve T 348 4 5 3 Pump Down An Operable Compressor For Repair To service an operable compressor pump the refrigerant into the condenser coil and receiver as follows a Install manifold gauge set Refer to Figure 4 6 b Frontseat the compressor suction service valve 6 by turning clockwise Install a jumper on the compressor mounted low pres sure switch Start the unit and run in cooling until 10 25 4 cm hg of vacuum is reached Shut the sys tem down and tag out system power source Frontseatthe compressor discharge service valve 1 and wait 5 minutes to verify that vacuum is main tained If the pressure rises above vacuum open the compressor discharge service valve and repeatsteps c and d until a vacuum is maintained Service or replace components as required and leak ch
52. at the Logic Board CODE LED see Figure 1 10 flashes Each Je RA Queue alarm code is a two digit number the firstsetofflashes is The alarm queue consist of 10 alarm locations When the first digit and after a slight pause the second set of the alarm queue is full the Logic Board will take the flashes is the second digit required action butthe alarm willnot be recorded When this situation occurs an Alarm Queue F ull alarm will be The Micromate control panel display will indicate alarms generated When the alarms are viewed this will be the with the code A or i where is an active alarm first alarm to be shown prefix 4 is an inactive alarm prefix and is the alarm number If no alarms are present the display will show 3 2 4 Alarm Clear To access the alarm codes press the UP and The user may clear inactive alarms using the Micromate DOWN arrow keys at the same time and hold for 3 control panel keypad Refer to paragraph 3 2 1 seconds If multiple alarms are present the user can scroll through each alarm by pressing the AUTO key 3 2 5 Exit Alarm Queue When the end of the alarm listis reached the display will To exit the alarm queue press the ON OFF key once or show Press VENT to scroll backward from the if no key is pressed for 30 seconds it will reset to normal latest alarm to the earliest alarm in the queue When mode using the VENT key to scroll back only the alarm code will be shown the
53. ault to low speed High Vent When this configuration is removed the unit will default to high speed in vent mode If not removed vent mode will default to low speed D Heat When this configuration is removed the unit will run on 10096 reheat instead of eat Reheat Cycle When the reheat cycle configuration is removed the unit is in reheat mode The default configuration is cycle clutch mode Transducers When the transducer configuration is removed transducers will assume to be present mE A Refrigerant R 22 R 134a When the refrigerant configuration is removed the refrigerant is set for R 22 The default refrigerant is R 134a Unit Type Rearmount unit enabled with G removed and H installed H Unit Type With H removed and G installed roof top unit will be enabled Factory Reserved for the manufacturer Invert H20 When this configuration is removed the logic for the water temperature switch will be inverted Es When this configuration is removed the voltage selection will be changed from 12 to 24 vdc Factory Reserved for the manufacturer Psig Bars When this configuration is removed the display will indicate pressures in bars When not removed the display will indicate pressures in psig C F When this configuration is removed the display will show temperatures in F When not removed the display will show temperatures in C E PI Reheat When this is removed reheat m
54. compressor Remove every other bolt from the seal cover of the new compressor in the same manner as the original compressor Mount the coil assembly with the wire in the same orientation as itwas mounted on the original compressor Tighten the mounting bolts to 45 50 ft Ibs 5 53 6 92 mkg i Mountthe rotor on the shaft Seatthe rotor to the hub using the rotor nut Be sure pulley turns freely without binding Tighten rotor nut by first noting torque neces sary to start the nut on the hub and then adding 50 ft lbs of torque j Install armature on shaft using original key and tight en mounting bolt to 20 ft lbs 2 8 Perform a check of the air gap between the inside face of the armature and the mating face of the rotor The airgap should be measured with a minimum of 50 psig 3 4 bar in the crankcase A preliminary check may be performed before the crankcase is pressur ized but a final check must be performed before the clutch is operated The gap should be between 0 030 and 0 060 inch 7 62 to 15 24 mm If required re move the six armature spacer nuts and spacer Add or remove shims to adjust gap Reinstall spacer nuts and tighten to 7 8 ft Ibs 1 0 to 1 1 mkg wiring and test clutch operation 4 15 3 Shim less Compressor Clutch As of February 4 2008 all 05G and 05K compressor clutches supplied by Carrier and built by Warner Electric will have an upgraded armature plate installed This new
55. d of metal rod prop and place in plate on cov wise er assembly 10 10 4 1 T 348 1 4 Turn Cam Lock 5 Places each side Figure 4 1 Opening Top Cover Evaporator 4 3 REMOVING TOP COVER CONDENSER The condenser cover assembly is of one piece construction To remove the cover from the condenser assembly do the following See Figure 4 2 a Twist all 4 of the 1 4 Turn cam locks counterclock wise b Grasp the condenser cover section under the bottom edge and lift up evenly 1 4 Turn Cam Locks 1 1 Figure 4 2 Condenser Cover Removal T 348 4 2 4 4 SUCTION AND DISCHARGE SERVICE VALVES The suction and discharge service valves Figure 4 3 are provided with a double seatand a gauge port which allows servicing of the compressor and refrigerantlines Turning the valve stem counterclockwise all the way out will backseat the valve to open the line to the compressor and close off the gauge port In normal operation the valve is backseated to allow full flow through the valve The valve should always be backseated before removing the gauge port cap Turning the valve stem clockwise all the way forward will frontseat the valve to isolate the compressor line and open the gauge port To measure suction or discharge pressure midseat the valve by opening the valve clockwise 1 4 to 1 2 turn With the valve stem midway between frontseated and backseated positions the suction or discharge gau
56. e flanges and break seal to be sure pressure is re leased Remove bolts Remove four bolts holding compressor to base Attach sling or other device to the compressor and re move compressor from the coach through the rear access door b NOTES Service replacement compressors are sold without service valves Valve pads are installed in their place The optional unloaders are not supplied as the cylinder heads are shipped with plugs Customer should retain the original unloader valves for use on the replacement compressor The piston plug that is removed from the replacement compressor head must be installed in the failed compressor if returning for warranty or core credit 10 10 4 11 3 Do not interchange allen head capscrews that mount the piston plug and unloader they are not interchangeable 4 Check oil level in service replacement compressor Refer to paragraphs 1 5 and 4 15 4 1 Electric Unloader 6 Bottom Plate Valve 7 OilDrain Plug 2 Suction Service 8 OilLevel Sight Glass Valve Charging Port 9 3 Suction Service 10 O ring Valve ll Discharge Service 4 Clutch Valve 5 Oil Fill Plug 12 Service Port Figure 4 12 Compressor g Remove the three socket head capscrews from the cylinder head s that have unloader valves installed SeeFigure 4 13 Remove the unloader valve and by pass piston assembly ke
57. e S be displayed if it is closed and OP will be displayed if itis open 17 Not used Speed Switch 19 i Maximum Setpoint This is the maximum value that the operator will be allowed to set the setpoint temperature The value can be modified in degrees with the up and down keys to a value between 60 F and 80 F P Minimum Setpoint This is the minimum value that the operator will be allowed to set the setpoint temperature The value can be modified in degrees with the up and down keys to a value between 60 F and 80 F T 348 2 6 10 10 Table 2 5 Parameter Codes Continued Code 20 Compressor Hours This is the number of hours of operation that the compressor has run with the Hig clutch energized in thousands P21 Compressor Hours This is the number of hours of operation that the compressor has run with the Low clutch energized in hundreds tens and ones P22 Evaporator Hours This is the number in thousands of hours of operation with the evaporator Hig fans energized h h P23 Evaporator Hours Low This is the number in hundreds tens and ones of hours of operation with the evaporator fans energized P24 Maintenance 1 Hour This is the value of compressor hours high P 20 at which maintenance alarm High 1 will be activated This value can be modified by the up and down arrow keys If both high and low values are zero the alarm is disabled P25 Maintenance 1 Hour This is the value of com
58. e at the desired set point 12 CONFIGURATION IDENTIFICATION Unit identification information is provided on a plate located inside the condenser and evaporator sections The provides the unitmodel number the unitserial number and the unit parts identification number P ID The model number identifies the overall unit configuration while the PID provides information on optional equipment and differences in detailed parts The following paragraphs provide descriptions of the options provided A tabular listing of unit model numbers and PID numbers used to assist the reader in identifying the equipment supplied is provided in Table 1 1 and Table 1 2 13 DESCRIPTION Various options may be factory field to the base unit These options are listed in the tables and described in the following subparagraphs 1 3 1 Condenser Cover Skins The condenser section may be fitted with one of two different cover assemblies dependent upon the curvature of the bus roof The assemblies available are identified as the 10 M radius cover and the 6 5 M radius cover 10 10 1 1 1 3 2 Condenser Electrical Kit The 68AC353 condenser kits are wired for either 24 Volt permanent magnet motors or 24 Volt brushless motors 1 3 3 Condenser Fan Kit The 68AC353 condenser kits are available with either 4 or 6 fans with either permanent magnet or brushless motors 13 4 Condenser Refrigeration Kit The 6
59. e compressor to 500 mi charge isolation valve 11 crons Close off vacuum pump isolation valve 15 and vacuum gauge isolation valve 14 and stop j Disconnect external 24 VDC to liquid solenoid valve pump Wait 5 minutes to verify that vacuum holds 13 e Once vacuum is maintained backseat compressor k Run and check refrigerant level Refer to paragraph Service KE and disconnect manifold gauge set f Check refrigerant level Refer to paragraph 4 8 1 It may be necessary to clear any alarms that have been generated Legend m Discharge mmm Suction 14 13 N BIZ 12 X 1 Discharge Service Valve 9 Manifold Gauge Set 2 Service Port Discharge 10 Vacuum Pump 3 Discharge Pressure Transducer 11 Reclaimer 4 Discharge Check Valve 12 Refrigerant Cylinder 5 High Pressure Switch 13 Thermistor Vacuum Gauge 6 Service Port Suction Service Valve 14 Vacuum Gauge Isolation Valve 7 Suction Pressure Transducer 15 Vacuum Pump Isolation Valve 8 Low Pressure S witch Figure 4 5 Compressor Service Connections T 348 10 10 CONDENSER Legend 9 ma Discharge gm Liquid S uction lt Refrigerant Flow 11 Seel 20 23 EVAPORATOR 3 114 COMPRESSOR 1 Discharge Service Valve 13 2 Service Port Discharge 14 3 Disch
60. earance is set lock the adjusting screws with the nuts torqued to 7 foot pounds You will need to hold the hex socket adjusting screw while torquing the lock nut NOTE Setting clearance is done with 30 psig in the compressor due to the crankshaft movement when charged If there is not30 psig in the com pressor when the clearance is set the clearance should be set on the lower end of the tolerance to allow for crankshaft movement when charged Check clearance again after com pressor is pressurized g Reconnect battery wiring and test clutch operation 4 15 4 Compressor Oil Level To check and if required correct the compressor oil level do the following a Operate the coach for at least one half hour at fast idle speed with the temperature controls at the cool est setting and the compressor fully loaded It may be necessary to pre heat the coach and or operate the system in the reheat mode to keep the compres sor fully loaded throughout this procedure b Ensure the system is fully charged refer to paragraph 4 8 1 and the compressor crankcase is warm to tne touch after fifteen minutes of operation c Shut off the system and immediately record the oil level the compressor sight glass See Figure 4 12 If the compressor is not level an average between the sight glass levels will have to be made to deter mine level d The correct oil level for this application should be be tween the bottom and 1 2 of the oil level s
61. eck the compressor NOTE To avoid the entrance of air never evacuate an open drive compressor below 500 microns f Using refrigeranthoses designed for vacuum service connect a vacuum pump to the center connection of the manifold gauge set Evacuate compressor to 500 microns Close off pump valve 23 isolate vacuum gauge valve 22 and stop pump Wait 5 minutes to verify that vacuum holds Once vacuum is maintained re connect low pres sure switch Backseat compressor service valves and disconnect manifold gauge set Check refrigerant level Refer to paragraph 4 8 1 It may be necessary to clear any alarms that have been generated 4 5 4 Removing Entire System Charge To remove the entire refrigerant charge do the following a Connect a manifold gauge set to the system as shown in Figure 4 6 b Connecta reclaimer to the center manifold gauge set connection c Energize the Liquid Line Solenoid Valve LSV 13 using an external power source 24 VDC d Recover refrigerant in accordance with reclaimer manufacturers instructions 2 4 6 REFRIGERANT LEAK CHECK A refrigerant leak check should always be performed after the system has been opened to replace or repair a component To check for leaks in the refrigeration system perform the following procedure NOTE 1015 emphasized that only the correct refrigerant should be used to pressurize the system Use of any other refrigerant w
62. efrigeration and or Evacuation Hose SAE 2196 R 134a Hose Fitting w O ring M14 x 1 5 High Side Field Service Coupler Low Side Field Service Coupler Figure 4 4 Manifold Gauge Set 134a 4 5 PUMPING THE SYSTEM DOWN OR REMOV ING THE REFRIGERANT CHARGE NOTE To avoid damage to the earth s ozone layer use arefrigerantrecovery system whenever remov ing refrigerant 4 5 1 System Pump Down For Low Side Repair To service or replace the filter drier thermostatic expansion valve suction line liquid line solenoid valve or evaporator coil pump the refrigerant to the condenser and receiver as follows a Install manifold gauge setto compressor discharge suction service ports items 2 amp 6 Refer to Figure 4 6 b Frontseat the charge isolation valve 11 by turning clockwise Disconnect suction pressure transducer 7 install jumper on the compressor mounted low pressure switch 8 c Start the system and run in cooling Stop the unit when suction reaches 2 psig 0 14 Bar d Frontseat the eee service valve 6 to trap refrigerantin the high side of the system between the compressor suction service valve and the charge isolation valve Wait 5 minutes to verify that system remains at approximately 2 psig 0 14 Bar If svstem pressure rises above 2 psig 0 14 Bar open the com pressor suction service valve and repeat steps cand d until the system remains at 2 psig 0 14 Bar T 348
63. eping the same capscrews with the assembly The original unloader valve must be transferred to the replacement compressor The lug arrangement removed from the replacement is installed in the original compressor as a seal If piston is stuck it may be extracted by threading a socket head capscrew into top of piston A small Teflon seat ring atthe bottom of the bypass piston plug must be removed GASKET SPRING 2 4 COVER 3 WW CH CAPSCREWS NOT INTERCHANGEABLE WITH CONTROL VALVE SCREWS COMPRESSOR HEAD 55 PISTON PLUG Figure 4 13 Removing Bypass Piston Plug h Remove the pressure switches and install on ment compressor after checking switch operation Refer to paragraph 4 10 i Remove clutch assemble and retain original clutch key Install on replacement compressor j Install compressor in unit by performing the removal steps in reverse It is recommended that new lock T 348 nuts be used when replacing compressor Install new gaskets on service valves and tighten bolts uniformly 55 to 80 ft Ibs suction and 20 to 30 ft Ibs discharge service valves Leak check connections and replace filter drier Re fer to paragraph 4 11 Using refrigerant hoses designed for vacuum service connecta vacuum pump see Figure 4 6 and evacu ate compressor to 500 microns Frontseat both man ifold valves to isolate the pump m O pen compressor service valves n Start unit and c
64. er fan 6 in low speed Energizes the A C clutch amp liquid solenoid valve LS V Energizes unloader 1 Energizes unloader 2 Energizes the fresh air damper Energizes the heat solenoid valve HS V Energizes the A C fault light output Energizes the boost pump Energizes the floor blower output Is energized by the logic board to turn the evaporator fans on high The contacts of this relay energize the coils of relays K1 K2 amp K4 Is energized by the logic board to turn the evaporator fans on low The contacts of this relay energize the coils of relays K1 K3 5 amp Is energized by the logic board to turn the condenser fans on high The contacts of this relay energize the coils of relays K7 K8 amp K10 Is energized by the logic board to turn the condenser fans on low The contacts of this relay energize the coils of relays K7 K9 K11 amp K12 Figure 1 11 Relay Board GR60 T 348 10 10 1 15 RELAY BOARD GR60 24VDC Continued e Thermal Circuit Breakers 1 Evaporator Fan 1 CB 2 Evaporator Fan 2 CB 3 Evaporator Fan 3 CB 4 Evaporator Fan 44 CB 5 Evaporator Fan 5 CB 6 Evaporator Fan 6 CB 7 Condenser Fan 1 CB 8 Condenser Fan 2 CB 9 Condenser Fan 3 CB10 Condenser Fan 4 11 Condenser Fan 5 CB12 Condenser Fan 6 15 Amp 15 Amp 15 Amp 15 Amp 15 Amp 15 Amp 15 Amp 15 Amp 15 Amp 15 Amp 15 Amp 15 Amp CB13 A C clutch Unloaders 1
65. ftop See Figure 1 2 Figure 1 1 System Component Identification 10 10 1 3 348 14 GENERAL DESCRIPTION 1 4 1 Compressor Assembly The compressor assembly is mounted in the engine compartment see Figure 1 1 and includes the refrigerant compressor clutch assembly suction and discharge service valves high pressure switch low pressure switch suction and discharge servicing charging ports and electric solenoid unloaders The compressor raises the pressure and temperature of the refrigerant and forces It into the condenser tubes The clutch assembly provides a means of belt driving the compressor by the bus engine The suction and discharge service valves enable servicing of the compressor Suction and discharge servicing charging ports mounted on the service valves enable connection of charging hoses for servicing of the compressor as well as other parts of the refrigerant circuit The high pressure switch contacts open on a pressure rise to shut down the system when abnormally high refrigerant pressures occur The electric unloaders provide a means of controlling compressor capacity which enables control of temperature inside the bus For more detailed information on the 05G compressor refer to the Operation and Service Manual number 62 02756 1 4 2 Discharge Check Valve A check valve is located in the discharge line close to the compressor see Figure 1 1 The discharge check valve is a spring loaded normally closed
66. ge port is open to both the compressor and the line TO DISCHARGE OR FROM SUCTION LIN sss oS VALVE STEM SERVICE PORT R 22 VALVE STEM 7 2 2 Service Valve Backseated counterclockwise II access VALVE CAP Figure 4 3 Suction or Discharge Service Valve COMPRESSOR Service Valve Frontseated clockwise ACCESS VALVE 134 10 10 4 4 1 Installing R 134a Manifold Guage Set A R 134a manifold gauge hose set with self sealing hoses is required for service of models covered within this manual The manifold gauge hose set is available from Carrier Transicold Carrier Transicold P N 07 00294 00 which includes items 1 through 6 Figure 4 4 To perform service using the manifold gauge hose set do the following a Preparing Manifold Gauge Hose Set For Use 1 If the manifold gauge hose set is new or was exposed to the atmosphere it will need to be eva cuated to remove contaminants and air as follows 2 Back seat turn counterclockwise both field service see Figure 4 4 both hand valves 3 Connectthe yellow hose to a vacuum pump and an R 134a cylinder 4 Evacuate to 10 inches of vacuum and then charge with R 134a to a slightly positive pressure of 1 0 psig 5 Frontseat both manifold gauge set hand valves and disconnect from cylinder The gauge set is now ready for use b Connecting Manifold Gauge Ho
67. ge Isolation Valve Discharge Line results in condensation of the refrigerant into a liquid The receiver collects and stores liquid refrigerant The receiver is also fitted with a fusible plug which protects the system from unsafe high pressure conditions and liquid level sight glasses to determine proper refrigerant liquid level The liquid refrigerant then passes thru the liquid line charge isolation valve to the evaporator An ambient temperature sensor measures ambient temperature and sends an electrical signal to the controller 5 Liquid Line 6 Condenser Fan and Motor Assembly 7 Ambient Temperature Sensor 8 Shipping Shut off Valves Figure 1 3 Condensing Section Components 10 10 T 348 1 4 5 Section The evaporator section Figure 1 4 includes the evaporator coils six blower and motor assemblies evaporator coil assemblies heater coil assemblies filter a thermostatic expansion valve liquid line solenoid service valves and condensate drain connections The evaporator coils provide heat transfer surface for transferring heatfrom air circulating overthe outside coil area to the refrigerant circulating inside the tubes thus providing cooling The heating coils provide heat transfer surface for transferring heat from engine coolant water circulating inside the tubes to air circulating over the outside surface of the tubes thus providing heating The fans circ
68. gh the listfrom the first to the last parameter or press the UP arrow to scroll from the lastto the first parameter When scrolling through the parameters the current parameter will be displayed for two seconds After two seconds the display will show the data for the current parameter When the last parameter is reached the list will wrap back to P 1 10 10 2 4 4 Test Mode With the system in normal operation the controller may be placed in the test mode by doing the following a b Enter the diagnostic mode by pressing the UP and DOWN arrow keys simultaneously for 3 seconds Enter the test mode immediately by pressing the COOL button five times If an alarm is present press the UP arrow key until is displayed In the test mode the display will read T where indicated the test number that is currently run ning The initial indication will be This indicates the controller is in the test mode and all relays are de en ergized Press the DOWN arrow key to bring the Mi cromate to the nexttest screen and energize the cor responding component s Press the UP arrow key move backwards through the list A listing of tests is provided in Table 2 4 To terminate testing press the 1 0 key 10 10 2 5 Table 2 4 Controller Test List T00 T01 T02 T03 Evaporator Fans High On Evaporator Fans Low On Condenser Fans High On Condenser Fans Low
69. h T 348 4 8 should open no continuity within required cut out tolerance Open cylinder valve andincrease pressure by closing the bleed off valve As pressure in creases switch should close continuity within re quired cut in tolerance g Replace or re install switch as required and recon nect wiring 4 11 FILTER DRIER 4 11 1 To Check Filter Drier The filter drier see Figure 4 8 must be changed if the drier is partially restricted or service has been performed on the refrigerant system Check for a restriction by feeling the inlet and outlet lines of the filter drier If the outlet side feels cooler than the inlet side then the filter drier should be changed 1 Filter Drier Inlet Solenoid Valve 2 Valve Service Port Hex Nut ORS 4 Filter Drier 5 Filter Drier Outlet Service Valve Figure 4 8 Filter Drier Removal 4 11 2 To Replace Filter Drier a Perform a low side pump down Refer to paragraph 4 5 1 Steps a to c Turn the driver s A C switch to OFF position c Frontseat the filter drier outlet service valve and place a new filter drier near the unit for immediate installation d Remove two screws securing the filter drier clamp Remove the filter drier clamp 44 WARNING The filter drier may contain liquid refriger ant Slowly loosen the ORS hex nuts to avoid refrigerant contactwith exposed skin or eyes o Using two open end wrenches slowly crack open the
70. hat self test has been successfully per formed and that there are no errors or alarms indi cated Refer to section 2 1 3 348 2 3 MODES OF OPERATION The system is operated by a Carrier Transicold Micromax microprocessor controller which consists of a logic board Figure 1 10 relay board Figure 1 15 or Figure 1 16 and manual operator switches The logic board regulates operational cycles of the system by energizing or de energizing Relay Board relays in response to deviations in interiortemperature Modes of operation include Cooling Heat and Vent Refer to COOL HIGH SPEED LOADED COOL HIGH SPEED 4 CYLINDERS COOL LOW SPEED 2 CYLINDERS SETPOINT REHEAT DUTY CYCLE 0 100 LOW SPEED 4 CYLINDERS HEAT LOW SPEED HEAT HIGH SPEED Cool Figure 2 1 and the following paragraphs for a description of each mode Figure 2 1 shows the Logic Board actions at various temperature deviations from setpoint On rising temperature changes occur when the temperature rises above Logic Board setpoints On falling temperature changes occur when temperatures falls below Logic Board set point The system will operate in these modes unless pressures override the Logic Board settings SETPOINT HEAT HIGH SPEED Heat Figure 2 1 Capacity Control Diagram 2 3 1 Temperature Control Temperature is controlled by maintaining the return air temperature measured at the return air grille 2 3 2 Cooling Mode Cooling
71. heck refrigerant level Refer to para graph 4 8 1 o Check compressor oil level Refer to paragraph 4 15 4 Add or remove oil if necessary p Check compressor unloader operation Refer to paragraph 4 15 5 q Backseat compressor service valves r Remove manifold gauge set Refer to paragraph 4 4 1 4 15 2 Transferring Compressor Clutch To remove a clutch see Figure 4 14 from a compressor and install on a replacement compressor do the following gt 6 Armature Spacer Nuts Retaining Capscrew Compressor Seal Cover 7 Coil 8 Rotor Lockwasher 3 8 Washe Rotor Nut Figure 4 14 Compressor Clutch a Place main battery disconnect switch in OFF position and lock b Tag and disconnect wiring to the clutch c Remove tension on drive belts remove drive belts d Remove the armature as a complete assembly by re moving the retaining capscrew lockwasher and spe cial 3 8 washer from the compressor crankshaft Use special tool CTD P N 07 00240 01 to prevent crankshaft rotation Install a 7 8 14 x 4 CTD P N 07 00381 00 caps crew into the center hole of the armature assembly and use it as a jacking bolt to remove the armature T 348 Use tool P N 07 00240 01 as in step a to pre vent crankshaft rotation f Using special tool CTD P N 07 00242 01 remove the rotor nut and rotor Retain original key Noting the position of the wire remove the three bolts holding the coil to the
72. hut off the reclaimer and verify the pressure does notrise Ifthe pressure rises continue reclaim ing until the pressure remains below atmospheric Add oil to compressor crankcase slowly through the oil fill plug opening see Figure 4 12 to bring level to mid range of allowed levels Evacuate compressor to 500 microns Backseat compressor suction and discharge valves start sys tem and recheck oil level Remove manifold gauge set 4 15 5 Checking Unloader Operation To check unloader operation do the following a Install a manifold gauge set as shown in Figure 4 6 Ensure both manifold valves are frontseated and cen ter connection is tight on blank fitting b Midseat compressor suction service valve Disconnect the suction pressure transducer Figure 1 6 This will force the controller to energize the unloader s Start the bus and run in cooling lower set point if re quired to ensure system remains in full speed cooling Locate the unloader connector at the compressor Observe manifold suction gauge while unplugging the connector Pressure should decrease 3 to 5 psi 0 2 to 0 4 bar when the unloader is unplugged and increase the same amount as the plug is recon nected Repeat test for second unloader if fitted If pressures do react as described check unload er coil or repair unloader mechanism as required When testing is complete reconnect transducer and unloader connectors and re
73. igh speed for a minimum period of 5 minutes The fans ill switch to low speed when discharge pressure decreases below 135 PSIG High speed will also remain activated if a high pressure alarm has been activated has not been locked out refer to Table T 348 2 3 9 Compressor Clutch Control A belt driven electric clutch is employed to transmit engine power to the air conditioning compressor De energizing the clutch electric coil disengages the clutch and removes power from the compressor The clutch willbe engaged when in cooling and disengaged when the system is off in heating or during high and low pressure conditions The clutch coil will be de energized if the discharge pressure rises to the cutout setting of the compressor mounted high pressure switch An alarm will be triggered if this condition exists for more than a 0 5 second The clutch coil will energize when the discharge falls to reset point of the high pressure switch The clutch coil will be de energized whenever the suction pressure decreases below 10 PSIG an alarm will be triggered if this condition exists for more than 10 seconds The clutch coil will energize when the suction pressure rises to the reset point If the alarm is triggered 3 times in a 30 minute time period the system will be locked out See 3 2 1 Alarm Codes The clutch coil is prevented from engagement when the ambient temperature is below ambient lockout setpoint
74. ightglass See Figure 4 12 If the oil level is correct release the coach into service If the level is above the 1 2 sight maximum proceed to step e If the level is be ow the 1 2 sightglass maximum proceed to step f WARNING Extreme care must be taken to ensure that all the refrigerant has been removed from the compressor crankcase or the resultant pressure will forcibly discharge compres sor oil e To remove oil and bring the level to the 1 2 sightglass maximum do the following 1 With the system off connecta manifold gauge set to the compressor suction and discharge service valves Front seat the service valves to isolate the compressor from the system See Figure 4 6 and reclaim the refrigerant to below atmospheric pres sure Shut off the reclaimer and verify the pressure does notrise If the pressure rises continue reclaim ing until the pressure remains below atmospheric 10 10 f 1 4 Drain pump out compressor until the level is brought to the proper level Evacuate the compressor to 500 microns Backseat the compressor service valves and repeatthe oillev el check procedure To add oil to the compressor do the following With the system off connecta manifold gauge set to the compressor suction and discharge service valves Front seat both service valves to isolate the compressor from the system See Figure 4 6 and reclaim the refrigerant to below atmospheric pres sure S
75. igure 1 11 Relay Board GR60 Continued 348 1 16 RELAY BOARD 24VDC 247 Or 2 F4 FS F6 F7 FB 017 038 018 068 047 061 090 077 031 bee 8063 miet ps 9030 902 Relays d LEDS K1 Energizes evaporator fans in low speed D2 Evaporator fans output active high K2 Energizes evaporator fans in high speed speed not energized in low speed D6 Evaporator fans output active K7 Energizes condenser fans in low speed D26 Condenser fans output active 8 Energizes condenser in high speed D30 Condenser fans on high speed not energized in low speed D51 A C clutch and liquid line solenoid valve K13 Energizes the A C clutch and liquid line output active solenoid valve D54 Unloader 1 output active K14 Energizes unloader 1 D57 Unloader 2 output active K15 Energizes unloader 2 D63 Heat output active RCV K16 Energizes fresh air damper D66 Fault output active K17 Energizes reheat coolant valve D69 Boost pump output active K18 Energizes the fault light output D72 Drivers liquid line solenoid valve active K19 Energizes the boost pump D17 Fresh air relay fuse out K20 Energizes the driver s liquid line solenoid D38 Unloader 1 relay fuse out valve D18 Evaporator fan motor relay fuse out b Connectors 068 Fault light out relay fuse out JA Relay board connector communication D47 Unloader 2 relay fuse out to system D61 Heater relay fuse out
76. ill contaminate the system and require additional evacuation T 348 4 6 Ensure the service valves open powerthe liq uid line solenoid valve from an external source If system is without refrigerant charge system with refrigerant vaporto build up pressure to approximate ly 30 PSIG 134 Add sufficient nitrogen to raise system pressure to 150 to 200 psig 10 21 to 13 61 bar Check for leaks The recommended procedure for finding leaks in a system is with an electronic leak de tector Testing joints with soap suds is satisfactory and may be necessary under conditions when an electronic leak detector will not function correctly Remove test gas and replace filter drier f Evacuate and dehydrate the system Refer to para graph 4 7 Charge the unit Refer to paragraph 4 8 Ensure that a Logic Board self test has been per formed and that there are no errors or alarms indi cated Refer to paragraph 2 1 3 4 7 EVACUATION AND DEHYDRATION 4 7 1 General The presence of moisture in a refrigeration system can have many undesirable effects The most common are copper plating acid sludge formation freezing up of metering devices by free water and formation of acids resulting in metal corrosion A triple evacuation R eferto paragraph 4 7 4 should be performed after a major System repair compressor evaporator or condenser replacement A one time evacuation Refer to par
77. in energized until the pressure increases to above 31 psig c Discharge Pressure Discharge pressure is also controlled by the unloaders 1 Compressor Unloader UV1 Relay When the dis charge pressure increases above set point A see chart below unloader UV1 is energized this un loader will remain energized until the pressure de creases below set point B see chart below Table 2 1 Unloader UV1 Relay Set PointA Set Point B S Unloader UV2 On R 134a sys tems when the discharge pressure increases above set point A see chart below unloader UV2 is ener gized this unloader will remain energized until the decreases below set point see chartbe ow Table 2 2 Unloader UV2 Relay Set PointA Set Point PSIG PSIG 2 3 7 Evaporator Fan Speed Selection Temperature control is the primary method of determining the fan speed selection Table 2 3 indicates relay operational status for the various fan motor states while Figure 2 1 provides Logic Board speed selections at various deviations from set point Table 2 3 Evaporator Fan Speed Relay Operation STATE HIGH EVAP FAN RELAY SPEED RELAYS Oi il 0 _ Low of High o 2 3 8 Condenser Fan Control The condenser fans start in low speed when the compressor clutch output is energized The fans will switch to high speed when the discharge pressure reaches 190 psig R 134a and will remain energized in h
78. is programmed to display set point temperature 2 To 5 system press the I O button to illuminate the indicator light and signal the Logic Board to per form start up Ensure the AUTO button indicator is illuminated If not press the AUTO button to place the system in the automatic mode After the pre trip inspection is completed the switches may be set in accordance with the desired control modes 3 If cooling only heating only or ventilation only is de sired press the corresponding button refer to Figure 1 14 to illuminate the indicator light and place the system in that mode of operation If low or high speed evaporator fan speed is desired press the FAN SPEED button to illuminate the indi cator light and bring speed to the desired level b 10 10 2 1 5 To open or close the fresh air damper if supplied press the FRESH AIR button to illuminate the indica tor light and bring the damper to the desired position To read interior or exterior temperature press the TEMPERATURE button to illuminate the indicator light and bring the display to the desired temperature After short delay the display will return to the default set point or return air temperature read ing 7 Setpoint may be changed by pressing the UP or DOWN arrow button The UP button will increase the setpoint temperature and the DOWN button will de crease the setpoint temperature For additional Micromate operating data refer t
79. itch to the off position NOTE Following completion of all maintenance or service activities the alarm queue should be cleared of anv origi nal alarms and anv alarms generated during service Refer to paragraph 3 2 1 NOTE To avoid damage to the earth s ozone laver use a refrigerant recoverv svstem whenever removing refriger ant When working with refrigerants you must comply with all local government environmental laws 4 1 MAINTENANCE SCHEDULE SVSTEM REFERENCE SYSTEM SECTION a EINE Maintenance X Pre trip Inspection after starting 2 2 X Check tension and condition of V belt None b Weekly Inspection X Perform daily inspection See above X Check condenser evaporator coils and air filters for cleanliness 1 5 X Check refrigerant hoses and compressor shaft seal for leaks Feel filter drier for excessive temperature drop across drier c Monthly Inspection and Maintenance Perform weekly inspection and maintenance See above Clean evaporator drain pans and hoses None Check wire harnesses for chafing and loose terminals Ae H Check fan motor bearings None Check compressor mounting bolts for tightness None Check fan motor brushes None 4 2 OPENING TOP COVER EVAPORATOR b Grasp the cover section under the bottom edge and lift up To open either side ofthe evaporatorassembly coverdo Locate metal rod prop secured behind the evapora a Twist all 5 of the 1 4 Turn cam locks counterclock d Liften
80. lating e Checkoutreplacementsensoror transducer Referto wires plugs attached to the Logic Board section 4 16 or 4 17 as applicable Damage to the board or wiring harness can f Repair or replace any defective componentis as re occur quired T 348 4 14 10 10 Table 4 2 Pressure Transducer Voltage Voltage Psig voltage Psig Voltage Psig Voltage Psig Voltage Psig Voltage _ Pao ose 0 0856 95 1397 150 1536 205 2475 260 308 Psig Voltage 50 0556 105 1495 160 2032 215 2573 3 12 0465 5 1007 1544 165 2083 220 252 275 3461 5 fej 1054 1593 2132 225 267 3210 E25 0712 80 1250 13s 1769 190 2325 245 2867 800 2406 is ei 90 1346 5 1587 200 255 2565 310 3504 4 19 LOGIC BOARD REPLACEMENT Control configuration is preset by the manufacturer and resetting of the parameters is not advised If a replacement Logic Board Is installed it is necessary to match the configuration jumpers See Figure 1 10 to the original board Table 4 3 provides a list of jumper functions Carrier is not responsible for failures or damage resulting from unauthorized changes Table 4 3 Logic Board Configuration Configuration High Reheat When this configuration is removed the unit will default to high speed reheat mode and in the low speed cool band If not removed heat reheat will def
81. lter Drier 4 8 Fresh Air System 1 6 Fuse 1 8 H HAZARD LABEL IDENTIFICATION Safety 1 Heat Lockout 1 8 Heating Cycle 1 12 Heating Mode 2 2 High Pressure Switch 1 7 1 8 4 8 Hour Meter 2 4 INTRODUCTION 1 1 L LEAK CHECK 4 6 Liquid Line Solenoid 2 4 4 9 Logic Board 1 15 2 1 3 1 4 15 Low Pressure Switch 1 7 1 8 4 8 M Maintenance Schedule 4 1 Micrormate Control Panel 2 1 3 1 Modes Operation 2 2 Noncondensibles Check For 4 7 O Oil Level 4 13 Operating Controls 1 7 Operating Instructions 2 1 OPTION DESCRIPTION 1 1 Index 1 T 348 P Pre Trip Inspection 2 1 Pressure Transducer 1 7 4 14 Pump Down 4 3 4 6 R Refrigerant Charge 1 7 4 3 4 7 Refrigerant R emoval 4 4 4 6 Refrigeration Cycle 1 10 Relay Board 1 16 1 18 Relay Board GR60 1 16 1 17 Rooftop Unit 1 4 S SAFETY DEVICES 1 8 SAFETY Safety 1 Self Diagnostics 3 1 SERVICE 4 1 Service Valves 4 2 Suction Pressure 2 3 Superheat 4 10 System Parameters 2 4 System Shutdown 2 1 System Start up 2 1 T 348 INDEX T Temperature Control 2 2 2 3 Temperature P ressure Chart 4 16 Temperature Sensor 1 7 4 13 4 14 Thermostatic Expansion Valve 1 7 4 10 Top Cover 4 1 4 2 Troubleshooting 3 1 Troubleshooting No CAN Communication 3 2 U Unloader Control 2 3 V Vent Mode 2 3 W Water Temperature S witch 1 7 Wiring S chematics 5 1 Index 2 10 10 WD
82. lugging valve orifice Ice formation at valve seat Power assembly failure Loss of bulb charge Broken capillary tube Wax oil or dirt plugging valve orifice Ice formation at valve seat Power assembly failure Loss of bulb charge Broken capillary 3 3 9 Heating Malfunction Insufficient heating No Heating Dirty or plugged heater core Reheat coolant solenoid valve s malfunctioning or plugged Low coolant level Strainer s plugged Hand valve s closed Water pumps defective Auxiliary Heater malfunctioning Reheat coolant solenoid valve s malfunctioning or plugged Controller malfunction Pump s malfunctioning Safety device open Check Tighten Replace Check Check Replace 4 16 4 17 Check Check Defrost coil Clean Clean Replace Repair Replace Replace Repair Replace Repair Replace Clean Replace Clean Defrost Replace Replace 4 13 Replace Replace 4 13 Clean Check R eplace Check Clean Open Repair R Repair R eplace Check R eplace Replace cl 1 Continuous Heating Reheat coolant solenoid valve stuck open T 348 3 6 10 10 SECTION 4 SERVICE 4A WARNING Be sure to observe warnings listed in the safety summary in the front of this manual before performing maintenance on the hvac svstem 4A WARNING Read the entire procedure before beginning work Park the coach on a level surface with parking brake applied Turn main electrical disconnect sw
83. move external 24 VDC from Liquid Line Solenoid h Charge system Refer to paragraph 4 8 2 4 7 4 Procedure for Evacuation and Dehydrating System Triple Evacuation a Remove refrigerant using a refrigerant recovery sys tem Refer to paragraph 4 5 4 b The recommended method is connecting lines re frigerant hoses designed for vacuum service as shown in Figure 4 6 c Energize the Liquid Line Solenoid Valve LSV 13 using an external power source 24 VDC d Start vacuum pump Slowly open valves halfway and then open vacuum gauge valve e Evacuate unit until vacuum gauge indicates 2000 mi crons Hg vacuum Close gauge valve vacuum pump valve and stop vacuum pump f Break the vacuum with nitrogen Raise system pres sure to approximately 2 psig g Purge the nitrogen from the system h Repeat steps d thru g one time i Start vacuum pump and open all valves Dehydrate unit to 500 microns Hg vacuum j Close off pump valve 23 and stop pump Wait five minutes to see if vacuum holds k Remove external 24 VDC from Liquid Line Solenoid Charge system Refer to paragraph 4 8 2 4 8 ADDING REFRIGERANT TO SYSTEM 4 8 1 Checking Refrigerant Charge conditions must be met to accurately The followin charge check the re a Coach engine operating at high idle b Unit operating fully loaded six cylinder in cool mode for 15 minutes c Compressor discharge head pressure to 150 PSIG
84. move manifold gauge set Disconnection of the suction pressure transducer will cause an A15 alarm Once the transducer is recon nected the alarm will go to inactive and can then be Cleared 4 16 TEMPERATURE SENSOR CHECKOUT a b An accurate ohmmeter must be used to check resist ance values shown in Table 4 1 Due to variations and inaccuracies in ohmmeters thermometers or other test equipment a reading within two percent ofthe chart value would be consid ered acceptable If a sensoris bad the resistance val ue would usually be much higher or lower than the value given in Table 4 1 Atleast one sensor lead must be disconnected from the controller before any reading can be taken Not doing so will result in a false reading Two preferred methods of determining the actual test temperature at the sensor are an ice bath at 32 F 0 C and or a calibrated digital temperature meter T 348 Table 4 1 Temperature Sensor Resistance d that the wiring to the transducer s is in good condition Resistance In Ohms Use digital volt ohmmeter to measure voltage F across the transducer connector corresponding to 20 165 300 terminals amp B See Figure 4 15 The reading should 117 800 85 500 f oe a vole sc measure wire ity between the connector positions corresponding to 1 62 400 See Figure 4 15 and 6 23 suction Logic 46 300 See Fig
85. n Compressor malfunction Check Replace Check Replace See Table 1 3 Electrical malfunction Coach power source defective Check R epair Circuit Breaker safety device open Check Reset 3 3 3 System Runs But Has Insufficient Cooling Compressor V Belt loose or defective Check Compressor valves defective See Table 1 3 Refrigeration system Abnormal pressures No or restricted evaporator air flow Expansion valve malfunction Restricted refrigerant flow Low refrigerant charge Service valves partially closed Safety device open Liquid solenoid valve stuck closed Restricted air flow No evaporator air flow or restriction Heating system Reheat coolant valve stuck open 3 3 4 Abnormal Pressures High discharge pressure Discharge transducer failure Refrigerant overcharge Noncondensable in system Condenser motor failure Condenser coil dirty Low discharge pressure Discharge transducer failure Compressor valve s worn or broken Low refrigerant charge High suction pressure Compressor valve s worn or broken See Table 1 3 Low suction pressure Suction and discharge pressures tend to equalize when system is operating Suction service valve partially closed Filter drier inlet valve partially closed Filter drier partially plugged Low refrigerant charge Expansion valve malfunction Restricted air flow Suction transducer failure 3 3 5 Abnormal Noise Or Vibrations Compressor 10 10 Loose mounting hardware Worn bearings
86. nt include high pressure switch HPS low pressure switch LPS circuit breakers 21 fuses a Pressure Switches High Pressure Switch HPS During the A C mode compressor operation will automatically stop ifthe HP S switch contacts open due to an unsafe operating condition Opening HPS contacts de energizes the compressor clutch shuttin down the compressor The high pressure switch HP S is installed in the center head of the compressor Low Pressure Switch LPS The low pressure switch is installed in the compressor andopens ona pressure drop to shut down the system when a low pressure condition occurs In addition if the microprocessor monitors a pressure less than 10 psig 0 68 bar by the suction pressure transducer mounted in the evaporator section the system will be shut down for at least one minute T 348 1 8 b Fuses and Circuit Breakers The system is protected against currentby supplied 125 amp fuse or circuit breaker Independent fuses or circuit breakers protect each evaporator blower motor and condenser motor assembly 5 amp fuses protect each relay board output 10 amp fuses protect ignition circuit output c Ambient Lockout The ambient temperature sensor located in the condenser section measures the condenser inlet air temperature When the temperature has fallen below the cut out set point the compressor is locked out until the temperature rises above the cut in setting The set points
87. o paragraph 2 4 2 1 3 Self Test and Diagnostics Check for Errors and or Alarms Self test of the main Logic Board electrical circuit is automatically initiated when the system is powered up If there is an error in the circuit an alarm will be indicated by nd LED s on the Logic Board If a Micromate is connected to the Logic Board the error code can also be read on the display If there are no errors in the circuit system will operate normally and flash the status LED at a one second interval During normal operation the Logic Board monitors system operating parameters for out of tolerance conditions If an out of tolerance condition occurs ALARM will be indicated through the code LED oron the Micromate Refer to section 3 for definition of system errors and alarms and general troubleshooting procedures 2 1 4 Stopping Placing the ON OFF switch in the OFF position or pressing the Micromate ON OFF button will stop the system operation by removing power to the Logic Board Note switches at the dash are supplied they will override control unless the J 3 plug on the logic board is disconnected 8 2 2 PRE TRIP INSPECTION After starting system allow system to stabilize for ten to fifteen minutes and check for the following a Listen for abnormal noises in compressor or fan mo tors b Check compressor oil level Refer to section 4 15 4 c Check refrigerant charge Refer to section 4 8 1 d Ensure t
88. ode will use the algorithm to the duty cycle of the heat valve If it is not removed the heat valve will be on constantly A p G K L M N o p Low Ambient Lockout When this configuration is removed the compressor clutch will disen gage at 25 F With this configuration in place the compressor will disengage at 45 F NOTE Designates J umpers 10 10 4 15 T 348 Table 4 4 R 134a Temperature Pressure Chart na farfar 146 3706 o 7 pus os pon pus s Las 2 pes pas Pun c 25 020 020 s on 37 026 05 060 059 076 974 102 158 12 19 138 ps 140 348 4 16 KE pas 17 11 278 15511 Ems 266 gt 22912 3 2 s 320 3 ise j 53 fs 1025 N 76 oy oy Wy Ww el el O LA 5 5 10 29 peri 1976 2 2 2 2 1 1 1 1 1 1 1 1 1 2 2 2 2 8 9 1 1 1 1 1 1 1 1 1 69 80 92 04 56 31 0 09 0 92 1 80 2 73 3 70 4 73 5 80 6 93 8 13 9 37 4 5 6 1 7 8 9 6 04 3 14 0 24 2 35 0 46 4 58 4 71 2 84 6 98 7
89. ondenser fans are operated to provide refrigeration as required The compressor is fitted with cylinder unloaders to match compressor capacity to the bus requirements Once interior temperature reaches the desired set point the system may operate in the clutch cycle or reheat mode A controller programmed for clutch cycle will de energize the compressor clutch and allow the system to operate in the vent mode until further cooling is required A controller programmed for reheat will maintain compressor operation and open the heat valve to allow reheating of the return air In the reheat mode interior temperature is maintained atthe desired set point while additional dehumidification takes place Controls may also be provided to allow manual operation of the evaporator fans in low or high speed and manual control of the fresh air damper in the open or closed position 15 REFRIGERATION SYSTEM COMPONENT SPECIFICATIONS a Refrigerant Charge R 134a 15 8 Lb 7 17 kg b Compressor UNTMODEL HES 05G No of Cylinders Weight Dry 145 Ibs W Clutch 65 77 kg Oil Charge 5 5 pints 2 6 liters 10 10 Oil Level Level in sight glass between Min Max marks on compressor crankcase curbside Approved Compressor Oils R 134a Castrol Icematic SW68C Mobil EAL Arctic 68 Emkarate RL68H c Thermostatic Expansion Valve Superheat Setting 12 2 F 6 7 1 C d High Pressure Switch HPS Opens at 350
90. ontrol window one at which the 2 first unloader will be energized This value can be modified between 0 and 10 degrees F The default value is 1 degree F P11 A C Control Window This is the number of Gates F above AC control window two at which the 3 evaporator fan speed will be set to low This value can be modified between 0 and 10 degrees F The default value is 1 degree F He i P12 at Control Window This is the number of degrees F below setpoint before the reheat coolantvalve is energized This value can be modified between 0 and 10 degrees F The default value is 2 degree F for heat and 4 degrees F for reheat Compressor Safety This number is the minimum time in minutes that the compressor must be off Off Delay after a high or low pressure alarm before it can be restarted This value can be modified between one and five minutes The default value is 1 P13 P14 Fan Delay This is the minimum time in seconds that the fans must run at a particular speed before changing to another speed This value can be modified between one and 60 seconds The default value is two seconds P15 Reheat Valve Delay This is the minimum time in seconds that the reheat valve must be in a par ticular state open closed before changing to another state This value can be modified between 1 and 60 seconds The default value is 2 seconds P16 Compressor CH This is the current state of the compressor high pressure switch input C L will Pressur
91. porator and condenser fans No work should be performed on the unit until all start stop switches are placed the OFF position and power supply is disconnected Always work in pairs Never work on the equipment alone In case of severe vibration or unusual noise stop the unit and investigate MAINTENANCE PRECAUTIONS Beware oF unannounced starting of the evaporator and condenser fans Do not open the unit cover before turning power off Be sure power is turned off before working on motors controllers solenoid valves and electrical controls Tag circuit breaker and power supply to prevent accidental energizing of circuit Do notbypass any electrical safety devices e g bridging an overload orusing any sortof jumper wires Problems with the system should be diagnosed and any necessary repairs performed by qualified service personnel When performing any arc welding on the unit disconnect all wire harness connectors from the modules in the control box Do not remove wire harness from the modules unless you are grounded to the unit frame with a static safe wrist strap In case of electrical fire open circuit switch and extinguish with CO gt never use water UNIT HAZARD LABEL IDENTIFICATION To help identify the hazard labels on the unit and explain the level of awareness each one carries explanations with appropriate consequences are provided below DANGER Indicates an immediate hazard which WILL result in severe personal
92. pressor hours low P 21 at which maintenance alarm Low 1 will be activated This value can be modified by the up and down arrow keys If both high and low values are zero the alarm is disabled P26 Maintenance 2 Hours This is the value of evaporator fan hours high P 22 at which maintenance High alarm 2 will be activated This value can be modified by the up and down ar row keys If both high and low values are zero the alarm is disabled 27 Maintenance 2 Hours This is the value of evaporator fan hours low P 23 at which maintenance alarm Low 2 will be activated This value can be modified by the up and down arrow keys If both high and low values are zero the alarm is disabled P28 Freeze Alarm Setting This is the value at which the freeze alarm will be activated The default value is 32 F This value can be modified between 20 F and 40 F in one degree in crements by using the arrow keys P29 JRelav Module Voltage This is the voltage being supplied to the relay module P30 Board Software This is the software version of the logic board Version P31 Software This is the software version of the display module ersion Heat Set Point Offset This value is the offset that can be used to change the points at which the unit switches between heat and vent in the heat mode A positive value will raise the critical temperatures winter use and a negative value will decrease the critical temperatures summer use
93. r is off The system is shut down until the voltage returns to normal levels The system is shut down until the voltage returns to normal levels All outputs except the evaporator fans will be de energized Both unloaders are ener gized One unloader is energi zed Condenser fans will run on high speed The clutch is de ener gized for the minimum off time The evaporator fans will remain running during this period After the compressor cycles off three times in 30 min utes all outputs will be de energized except for the evaporator fans and heat and the system is locked out until the pow er is cycled or the alarm is reset T 348 Table 3 2 Alarm Codes Continued ALARM TITLE CAUSE REMEDY CONTROLLER NO RESPONSE High Discharge Pressure discharge pres Check discharge The clutch is de ener sure switch open or pressure transducer gized for the minimum wiring defective reading wiring or off time The condenser cause of high dis and evaporator fans will charge pressure Re remain running during fer to section 3 3 4 this period After the compressor cycles off three times in 30 min utes all outputs will be de energized except for the evaporator fans and heat and the system is locked out until the er is cycled or the alarm is reset Breaker Trip Blown Fuse JA breaker fuse on the Check breakers fuse Alarm will be generated Alarm relay board has for tripped device Re tripped
94. rator fans 1 2 3 amp 4 in low speed Energizes evaporator fans 3 amp 4 in high speed not energized in low speed Energizes evaporator fan 5 in high speed or evaporator fans 5 amp 6 in low speed Energizes evaporator fan 6 in high speed not energized in low speed Connects the negative side of evaporator fans 1 amp 2 to ground high speed Connects negative side of evaporator fans 1 amp 2 to positive side of evaporator fans 3 amp 4 in low speed Connects the negative side of evaporator fan 5 to ground in high speed Connects the negative side of evaporator fan 5 to positive side of evaporator fan 6 in low speed Energizes condenser fans 1 amp 2 in high speed or condenser fans 1 2 3 amp 4 in low speed Energizes condenser fans 3 amp 4 in high speed not energized in low speed Energizes condenser fan 5 in high speed or condenser fans 5 amp 6 in low speed K10 Energizes condenser fan 6 in high speed K11 not energized in low speed Connects the negative side of condenser fans 1 amp 2 to ground high speed Connects negative side of condenser fans 1 amp 2 to the positive side of condenser fans 3 amp 4 in low speed 12 K13 K14 K15 K16 K17 K18 K19 K20 K21 K22 K23 K24 057 Ops4 i T 2 bis Connects the negative side of condenser fan 5 to ground high speed Connects the negative side of condenser fan 5 to the positive side of condens
95. repeating streams are shown STOP The Gateway unit is bad 10 10 s A12 High Voltage The battery voltage 15 Check repair or re greater than 32 volts alternator Low Voltage The battery voltage is less than 17 volts Return Air Probe Failure Suction Pressure Transducer F ailure Low Pressure Shutdown Discharge Pressure Transducer F ailure 10 10 Table 3 2 Alarm Codes ALARM TITLE CAUSE REMEDY CONTROLLER NO RESPONSE Coil temperature is less than 32 F and the compressor is op erating Return air tempera ture sensor failure or wiring defective Suction pressure transducer failure or wiring defective Discharge pressure transducer failure or wiring defective Low suction pressure switch open or wiring defective 3 3 Check causes of coil freezing Refer to section 3 3 7 Check repair or re place wiring or alter nator Ensure all connectors are plugged in Check sensor resistance or wiring Refer to para graph 4 16 Replace sensor or repair wir ing Ensure all connectors are plugged in Check sensor voltage or wir ing Replace sensor or repair wiring Ensure all connectors are plugged in Check sensor voltage or wir ing Replace sensor or repair wiring Check cause of low suction pressure Re fer to section 3 3 4 An alarm will be gener ated and the system will shutdown The evapora tor fans will remain run ning while the compres so
96. rge level in accordance with the proce dures of paragraph 4 8 1 4 8 3 Adding Partial Charge a Install manifold gauge set at the compressor suction service valve See Figure 4 6 b Place appropriate refrigerant cylinder on scale Pre pare to charge vapor refrigerant by connecting charg ing hose from container to center connection gauge manifold P urge air from hoses c Run the unit in the cool mode as described in section 4 8 1 With the suction service valve midseated open the refrigerant cvlinder valve and add vapor charge until the white balls are floating and a liquid level is de tected in the receiver sight glasses d Backseat the suction service valve Close the vapor valve on the refrigerant drum and note weight Re move the manifold gauge set and replace all valve caps 4 9 CHECKING FOR NONCONDENSIBLES To check for noncondensibles proceed as follows a Stabilize svstem to equalize pressure between the suction and discharge side of the svstem b Check temperature at the condenser and receiver c Check pressure at the filter drier inlet service valve d Check saturation pressure as it corresponds to the condenser receiver temperature using the Temperat ure Pressure Chart Table 4 4 e If gauge reading is 3 psig 0 20 bar or more than the saturation pressure in step d noncondensibles are present f Remove refrigerant using a refrigerant recoverv svs tem g Evacuate and dehvdrate the svs
97. se Set To connect the manifold gauge hose set for reading pressures do the following 1 Remove service valve stem cap and check to make sure it is backseated Remove access valve cap 2 Connect the field service coupler see Figure 4 4 to the access valve 3 Turn field service coupling knob clockwise which will open the system to the gauge set 4 Read system pressures 5 Repeat the procedure to connect the other side of the gauge set Removing the Manifold Gauge Set 1 While the compressor is still backseat the high side service valve 2 Midseat both hand valves on the manifold gauge set and allow the pressure in the manifold gauge set to be drawn down to low side pressure This returns any liquid that may be in the high side hose to the system CAUTION To prevent trapping liquid refrigerant the manifold gauge setbe sure setis broughtto suction pressure before disconnecting 3 Backseat the low side service valve Backseat both field service couplers and frontseat both manifold set hand valves Remove the couplers from the access valves 4 Install both service valve stem caps and access valve caps finger tight only 10 10 4 3 Low Pressure High Pressure Gauge Backseated Hand Valve rontseated Hand Valve To Low Side Access Valve To High Side Access Valve 5 Red Knob 6 Blue Knob Manifold Gauge Set Hose Fitting 0 5 16 Acme R
98. system through one of two relay boards and may be interrogated GER the optional CAN Data Communication Link T 348 Table 1 1 Option Legend Condenser Skins Kit Condenser Electrical Kit Condenser Fan Kit 2 Evaporator Skins Kit Evaporator Blower Kit Evaporator Refrigeration Kit Evaporator Connection Kit S D Left ORS With Out Front Connection Evaporator Connection Kit Indash Air Exchange Kit Controller Kit Micromax With GR60 Relay Board right Micromax Relay Board With CAN DATA right Micromax Relay Board igh ian Relay Board With CAN DATA e Micromax With GR60 Relay Board left Table 1 2 Option Table PID Condenser PID Evaporator AC353E Condenser Skins Kit Condenser Electrical Kit Condenser Fan Kit 3 Row Coil Refrigeration Kit MODEL 68AC 353 00002 00002 00004 00004 00006 00006 00007 348 1 2 Evaporator Connection Kit s D Evaporator Connection Kit In Dash Evaporator Refrigeration Kit MERE bab Evaporator Skins Kit ao es Evaporator Blower Kit GC Kit 10 10 Table 1 3 Additional Support Manuals Dash Air Option 1 Compressor 8 Main Harness 2 Discharge Check Valve 9 Driver Control 3 Refrigerant Lines 10 Power Harness 4 Compressor Harness 11 Main Circuit Breaker 5 Electronics Boards Power Relay 12 Battery 6 Liquid Line Solenoid 13 Alternator 7 AC353 Roo
99. tem Refer to para graph 4 7 4 T 348 h Charge the unit Refer to paragraph 4 8 2 4 10 CHECKING AND REPLACING HIGH OR LOW PRESSURE SWITCH 4A WARNING Do not use a nitrogen cvlinder without a pressure regulator 4A WARNING Do not use oxygen in or near a refrigeration system as an explosion may occur a Disconnect wiring and remove switch from unit All units are equipped with a schrader valve at the pres sure switch connections Connect switch to a cylinder of dry nitrogen See Figure 4 7 o Cylinder Valve and Gauge Pressure Regulator Nitrogen Cylinder Pressure Gauge 0 to 400 psig 0 to 27 22 bar Bleed Off Valve 1 4 inch Connection ON Figure 4 7 Checking High Pressure Switch c Connect an ohmmeter across switch terminals d Setnitrogen pressure regulator higher than the upper switch setting refer to paragraph 1 5 e For a high pressure switch close cylinder valve and open bleed off valve Open cylinder valve and slowly close bleed off valve The switch should open no continuity within required cut out tolerance Close cylinder valve and release pressure through the bleed off valve As pressure drops switch should close continuity within required cut in tolerance f For a low pressure switch close cylinder valve and bleed off valve Open cylinder valve to bring pres sure above the cutout setting Close the cylinder valve and slowly open bleed off valve The switc
100. the evaporator tubes is colder than the air that is circulated over the evaporator tubes by the evaporator fans Heat transfer is established from the evaporator air flowing over the tubes to the refrigerant flowing inside the tubes The evaporator tubes have aluminum fins to increase heat transfer from the air to the refrigerant therefore the cooler air is circulated to the interior of the bus Liquid line solenoid valve closes during shutdown to prevent refrigerant flow The transfer of heat from the air to the low temperature liquid refrigerant in the evaporator causes the liquid to vaporize This low temperature low pressure vapor passes through the suction line and returns to the compressor where the cycle repeats 10 10 Legend 22 a Discharge 23 N CONDENSER gm liquid d 21 Suction lt Refrigerant Flow 24 Discharge Service Valve Discharge Check Valve Service Port Discharge 20 20 High Pressure Switch Discharge Pressure Transducer Low Pressure Switch Crankcase Dash Air Liquid Line Option Suction Service Valve P ort Dash Air Suction Tee Option 10 Suction Pressure Transducer Evaporator Coil 12 Thermal Expansion Valve TXV 13 TXV Bulb 14 TXV Equalizer Line 15 Liquid Line Solenoid Valve 16 Filter Drier 19
101. trol it remains energized for two minutes to prevent short cycling Only one unloader may change state ata time when staging is required O perating parameters for temperature control suction pressure control and discharge pressure control are as follows a Temperature Control The unloaders are used to control system capacity by controlling compressor capacity 1 Compressor Unloader UV1 Relay When return air temperature falls to less than 2 F 1 1 C above set point unloader UV1 is energized If temperature rises to greater than 3 F 1 C above set point UV 1 will be de energized to place the compressor at 100 capacity 2 Compressor Unloader UV2 Relay When return air temperature falls to less than 1 F 0 6 C above set point unloader UV2 is energized If temperature rises to greater than 2 F 1 1 C above set point UV 2 will be de energized to place the compressor at 6696 capacity 10 10 2 3 b Suction Pressure The unloaders are used to control suction pressure and thereby prevent coil frosting 1 Compressor Unloader UV1 Relay When the suction pressure decreases below 26 psig unloader UV1 is energized unloading a cylinder bank two cylinders this output will remain energized until the pressure increases to above 34 psig 2 Compressor Unloader UV2 Relay When suction pressure decreases below 23 psig unloader UV2 is energized unloading the second compressor cylin der bank this output will rema
102. ulate the air over the coils The air filters remove dirt particles from the air Evaporator Coil Assembly Heat Coil Evaporator Return Air Filter Expansion Valve Filter Drier Blower amp Motor Assembly Suction Line before it passes over the coils The filter drier removes moisture and debris from the liquid refrigerant before it enters the thermostatic expansion valve the evaporator assembly Service valves enable isolation of the filter drier for service The thermostatic expansion valve meters flow of refrigerant entering the evaporator coils The liquid line solenoid valve closes when system is shut down to prevent flooding of the evaporator coils with liquid refrigerant A heat valve controls the flow of engine coolant water to the heating coils upon receipt of a signal from the controller The condensate drain connections provide a means for connecting tubing for disposing of condensate collected on the evaporator coils during cooling operation PID Model Serial Number Tag 8 Discharge Line 9 Service Valve 10 Liquid Line Solenoid 11 Heat Line Connection 12 Control Panel 13 Fresh Air Damper Figure 1 4 Evaporator Section Components 1 4 6 Fresh Air System Fresh Air System consists of a damper and damper operator The damper operator may be controlled by the driver if a switch is provided In the automatic mode itis controlled by the Micromax to open and close the 348
103. ure 4 15 and J 6 20 discharge Logic Board See Figure 5 2 for Logic Board loca 34 500 Log 32 700 Use a digital volt ohmmeter to measure voltage across the transducer at terminals A amp C See Figure 4 15 Compare to values in Table 4 1 A read 19 900 15 300 ing within two percent of the values the table would 11 900 be considered good 7 100 110 120 4 17 PRESSURE TRANSDUCER CHECKOUT O gl 60 m 9 NOTE System must be operating to check transduc ers Figure 4 15 Transducer Terminal Location a With the system running use the driver display and manifold gauges to check suction and or discharge 4 18 REPLACING SENSORS AND TRANSDUCERS pressure s simultaneously b Determine with the gauges whether one or both pres a Place main battery disconnect switch in OFF position sure readouts are correct If one is correct exchange and lock the pressure transducer locations If the problem T moves with the transducer replace the faulty trans b Tag and disconnect wiring from defective sensor or ducer transducer If the driver display read out disagrees with both val c Remove and replace defective sensor or transducer ues shown on the manifold gauges proceed to step d Sensor transducer connections are fitted with Schreader valves to facilitate replacement A CAUTION d Connect wiring to replacement sensor or transducer Use care when checking manipu
104. ut EEN REN 1 9 Figure 1 6 Refrigerant Flow Diagram 1 11 Figure 1 7 Heat Flow Diagram 1 12 Figure 1 8 Control Panel uuu a pu a a 1 13 19 Control Panel u pas at aus DEEP naan Sas masa 1 14 Figure 1 10 Logic Board eni et a eer be t x e e d e e Rte cen a 1 15 Figure 1 11 Relay Board 60 1 16 Figure L 12 Relay Board iie ue ukasa obs niaaa a Robur 1 18 Figure 1 13 Logic Board Data Communications 1 19 Figure 1 14 Micromate Control Panel 1 20 Figure 2 1 Capacity Control Diagram 2 2 Figure 4 1 Opening Top Cover 4 2 Figure 4 2 Condenser Cover Removal 4 2 Figure 4 3 Suction or Discharge Service Valve 4 2 Figure 4 4 Manifold Gauge Set R 134a 4 3 Figure 4 5 Compressor Service Connections 4 4 Figure
105. vents the circulation of cooler air throughout the vehicle as the engine comes up to temperature 2 3 4 Boost Pump When the unitis in the heat mode and if a boost pump is supplied by the coach manufacturer the boost pump relay is energized providing 24 VDC to activate the boost pump 2 3 5 Vent Mode In the vent mode the evaporator fans are operated to circulate air in the bus interior 2 3 6 Compressor Unloader Control When operating in cooling the unloaders are used to reduce system capacity as return air temperature approaches set point Operation of the unloaders balances system capacity with the load and thereby prevents overshoot from set point Relay Board mounted unloader outputs control the capacity of the compressor by energizing or de energizing unloader solenoid valves The model 05G compressor has three banks of two cylinders each Energizing a valve de activates a bank of cylinders The outboard cylinder banks of the 05G are with unloader valves UV1 and UV2 each controlling two cylinders this allows the 05G 7 with two four or six cylinders Whenever the compressor is started the unloaders are energized for a preset delay time to reduce starting torque After the delay unloaders may be de energized Any subsequent changes between energizing and de energizing the unloaders for temperature control is also staged for a preset delay time Once an unloader is energized for pressure con
106. which is ata temperature lowerthan the refrigerant over the outside of the condenser tubes Heat transfer is established from the refrigerant inside the tubes to the condenser air flowing over the tubes The condensertubes have fins designed to improve the transfer of heat from the refrigerant gas to the air this removal of heat causes the refrigerant to liquefy thus liquid refrigerant leaves the condenser and flows to the receiver The receiver serves as a liquid refrigerant reservoir so that a constant supply of liquid is available to the evaporators as needed and acts as a storage space when pumping down the system The receiver is equipped with two sight glasses to observe refrigerant charge level The refrigerant leaves the receiver and passes through the charge isolation valve to the liquid line solenoid T 348 valve From the Iud line solenoid valve the refrigerant enters the filter drier where an absorbent keeps the refrigerant clean and dry From the filter drier the liquid refrigerant then flows through the liquid line service valve to the thermostatic expansion valve The liquid line is equipped with a sight glass to observe the refrigerant for restricted flow The thermostatic expansion valve reduces pressure and temperature of the liquid and meters the flow of liquid refrigerant to the evaporator to obtain maximum use of the evaporator heat transfer surface The low pressure low temperature liquid that flows into
107. will be programmed to cut outat 45 F 7 2 C and cut in at 50 F C This setting protects the compressor from damage caused by operation at low pressures d Water Temperature Switch WTS When the the engine coolant temperature has fallen below the cut out set point the evaporator fans are locked out until the temperature rises above the cut in set point The set point will be programmed to cut in at 105 F 41 C 10 10 19 AIR FLOW coach ths for ambient air through the condenser and air through the evaporator are illustrated in Figure 1 5 COIL RETURN AIR FILTERS EVAPORATOR COIL HEATER COIL HEATER COIL EVAPORATOR COIL COACH RETURN AIR FILTER EVAPORATOR Return To Ambient From Ambient Through Fan Through Fan From Ambient Through Condenser CONDENSER hrough Condenser 10 10 Figure 1 5 System Air Flow 1 9 T 348 1 10 AIR CONDITIONING REFRIGERATION CYCLE When air conditioning cooling is selected by the controller the unit operates as a vapor compression system using R 134a as the refrigerant See Figure 1 6 The main components of the system are the reciprocating compressor air cooled condenser coils receiver filter drier thermostatic expansion valve liquid line solenoid valve and evaporator coils The compressor raises the pressure and the temperature of the refrigerant and forces it into the condenser tubes The condenser fan circulates surrounding air
108. y discharge compressor oil CAUTION Do not under any circumstances attempt to service the microprocessor Should a problem develop with the microprocessor replace it 4A CAUTION To prevent trapping liquid refrigerant in the manifold gauge set be sure set is brought to suction pressure before disconnecting 4A CAUTION Use care when checking manipulating wires plugs attached to theLogic Board Damageto the board or wiring harness can occur T 348 Safetv 2 10 10 SECTION 1 DESCRIPTION 1 1 INTRODUCTION This manual contains Instructions Service Instructions and Electrical Data forthe Model 68AC353 Air Conditioning and Heating equipment furnished by Carrier Transport Air Conditioning as shown in Table 1 1 and Table 1 2 Additional support manuals are referenced in Table 1 3 The Carrier Transicold model 68AC series units are of lightweight frame construction designed to be installed on the vehicle roof Model 68AC353 systems consists of a condensing section evaporator section and an engine compartment mounted compressor To complete the system the air conditioning and heating equipment interfaces with electrical cabling refrigerant piping engine coolant piping for heating duct work and other components furnished by the bus manufacturer See Figure 1 1 Operation of the units is controlled automatically by a microprocessor based Micromax Controller which maintains the vehicle s interior temperatur

OPERATION AND SERVICE for 68AC353

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