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warning - North America Transport Air Conditioning

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2. 1 2 4 Main Control Box The main control box includes a main controller logic board assembly See Figure 1 8 a relay board anda connector ribbon cable See Figure 1 9 The main controller microprocessor module contains the electronic hardware to measure inputs and process the a Connectors J1 24 Volt power input J2 Micromate Display interface J3 Manual control inputs Interlock inputs WTS low pressure switch etc Relay Board interface Sensor inputs Thermistors etc Diagnostics interface RS232 DB9 A P Configuration Jumpers outputs to automatically control the air conditioning and heating system to maintain temperatures inside the coach The microprocessor section has built in memory facility for checking proper operation this includes checks of the program memory data memory and analog It has a self test feature which is executed when the system is first powered up D2 Blinks once per second in normal operation On steady to indicate alarms detected D3 Off in normal operation blinks out alarm codes 2 digits each when alarms detected Figure 1 8 Logic Board 1 7 T 329 24V O Ot i F2 F4 FS F6 F8 F9 210 038 018 068 047 061 090 077 031 083 B 054 057 051 030 026 E d D6 a Relays K1 K2 K7 K8 K13 K14 K15 K16 K17 K18 K19 K20
3. 1 8 1 10 System Operating Controls upper left hand switch panel 1 9 1 11 Heating System Flow Diagram 1 12 1 12 Air Conditioning Refrigerant Flow Diagram 1 1 14 2 1 Capacity Control Diagram 2 2 4 1 Suction or Discharge Service Valve 4 1 4 2 Manifold Gauge Set R 134a 4 2 4 3 Compressor Service Connections 4 3 4 4 Refrigerant Service Connections 4 5 4 5 Checking High Pressure Switch 4 7 4 6 Thermostatic Expansion Valve 4 7 4 7 Thermostatic Expansion Valve Bulb and Thermocouple Installation 4 8 4 8 Removing Bypass Piston Plug 2 4 9 4 9 Model O5G Compressor 4 9 4 10 Removing Driver Control Box 4 14 5 1 Electrical Schematic Diagram Legend and Symbols
4. 5 1 5 2 Electrical Schematic Diagram 5 2 5 3 Electrical Schematic Diagram 5 3 5 4 Electrical Schematic Diagram 5 4 5 5 Electrical Schematic Diagram 5 5 LIST OF TABLES Table Page 1 1 Part Model Number Chart 1 1 1 2 Additional Support Manuals 2 1 1 221 Controller Testlist 4 ovas cibi RO CI E oe aay ea ate eee E ie 2 4 2 2 Parameter Codes 2 5 3 1 Error Godes gh heed eine tcl oiu 3 1 23 2 Alatim CodeS 3 2 3 3 General System Troubleshooting Procedures 3 4 4 1 Checking Refrigerant Charge 4 6 4 2 Checking Refrigerant Charge 4 6 4 3 Temperature Sensor AT TSC TSD and TSR Resistance 4 11 4 4 Suction and Discharge Pressure Transducer SPT and DPT Voltage
5. 4 12 4 5 Logic Board Configuration 4 15 4 6 R 134a Temperature Pressure 4 4 16 T 329 iv SECTION 1 DESCRIPTION 1 1 INTRODUCTION This manual contains Operating and Service Instructions and Electrical Data for the Model 68G5 105 Coach Air Conditioning and Heating equipment with Micromax furnished by Carrier Transicold Division for the MCI J Series Intercity coach Table 1 1 provides a model number chart The Model 68G5 105 equipment see Figure 1 1 consist of a condenser a main evaporator with integral heater a driver evaporator with integral heater optional parcel rack evaporators compressor assembly main control box driver display panel check valve assembly temperature sensors and a bypass heat valve The 68G5 air conditioning and heating equipment interfaces with electrical cabling a parcel rack evaporator thermostat kit refrigerant piping engine coolant piping ductwork and other components furnished by the coach manufacturer to complete the system Table 1 1 Part Model Number Chart Modei No Refrigerant Controller Fan Motors Parcel Rack Connection 6865 105 R 134a 24VDC Table 1 2 Additional Support Manuals Driver Evaporator Driver Evaporator Driver Display Control Box Panel Parcel Rack Evaporator A Main Evaporator Main Controller Aisle
6. 3 1 3 27 SYSTEM ALARMS be 3 1 3 2 1 Alarm Codes 2 2 2 3 1 3 2 2 VACHIVALON rimus viia emiaex edu RR ath Senay 3 1 3 2 3 Alarm Queue lx as ea Mote hae a E 3 1 3 2 4 Alarm Clear ite aan 3 1 3 9 TROUBLESHOOTING 3 1 3 3 1 System Will Not Cool 2 3 4 3 3 2 System Runs But Has Insufficient Cooling 3 4 3 3 3 Abnormal Pressures 3 4 3 3 4 Abnormal Noise Or Vibrations 3 4 3 3 5 Control System 2 2 3 5 3 3 6 No Evaporator Air Flow Or Restricted Air Flow 3 5 3 3 7 Expansion Valve 3 5 3 3 8 Heating Malfunction 2 222 3 5 0 oa tos ET 4 1 4 1 MAINTENANCE 4 1 4 2 SUCTION AND DISCHARGE SERVICE VALVES 4
7. wines eave E abe a Anges RA CERTA EA Rua 2 2 2 9 3 Heating ree sabe ned 2 2 2 3 4 Vent Mode 2 2 2 3 5 Compressor Unloader 2 2 2 3 6 Evaporator Fan Speed Selection 2 3 2 3 7 Fan Motor Operation Sequence 2 3 2 3 8 Condenser Fan Control en 2 3 2 3 9 Compressor Clutch 0 1 2 4 2 3 10 Liquid Line Solenoid Control 2 4 2 39 11 Alarm Description mur E iR RUE VOU dee UEM eat ae eee 2 4 2 3 12 Hour Meters 2 4 i T 329 TABLE CONTENTS Continued Section Page 24 MICROPROCESSOR DIAGNOSTICS 2 4 tigen 2 4 2 4 2 Diagnostic ed ak Pah ee Re ee he eA a ee 2 4 2 4 3 System Parameters RP REX EE 2 4 2 4 4 Test 2 4 TROUBLESHOOTING 22 55 52 pe TUR 3 1 3 4 SELF DIAGNOSTICS
8. top of piston A small Teflon seat ring at the bottom of the piston must be removed GASKET CAPSCREWS NOT INTERCHANGEABLE WITH CONTROL VALVE SCREWS SPRING FLANGE COVER COMPRESSOR HEAD BYPASS PISTON PLUG Figure 4 8 Removing Bypass Piston Plug Remove the high pressure switch and pressure transducer assemblies and install on replacement compressor after checking switch operation Install compressor in unit by performing steps c through g in reverse sequence It is recommended that new locknuts be used when replacing compressor Install new gaskets on service valves and tighten bolts uniformly d Re install and tension the compressor drive belt e Unlock and turn main battery disconnect switch to ON position Attach two lines with hand valves near vacuum pump to the suction and discharge service valves Fully backseat open counterclockwise both suction and discharge service valves Remove vacuum pump lines and install manifold gauges Start unit and check refrigerant level Refer to paragraph 4 7 1 Check compressor oil level Refer to paragraph 4 12 5 Add or remove oil if necessary Check compressor unloader operation 4 12 4 Compressor Unloaders Although the electric unloaders are non adjustable they will require some periodic maintenance Service kits are available for repair of the electric unloaders solenoid and stem assemblies
9. Shaft Seal Reservoir Twin Port Only Suction Pressure Transducer Bracket Belt Guard Weatherpack Clutch Coil Connector Electric Solenoid Unloader Discharge Valve Connection Size 16 ORS Discharge Service Valve Discharge Valve Charging Port O Ring Oil Drain Plug Solenoid Unloader Electric Connectors High Pressure Switch Discharge Pressure Transducer Capscrew Lockwasher Special Washer Lock Nut Key Suction Valve Charging Port Suction Service Valve Clutch Assembly Oil Fill Plug 23 2 Level Sightglass Suction Valve Connection Size 24 ORS O Ring 0 0 I o Oi gt CO Figure 1 3 Compressor Assembly 1 3 T 329 1 2 2 Compressor Assembly The compressor assembly See Figure 1 3 includes the refrigerant compressor clutch assembly suction and discharge service valves high pressure switch suction and discharge pressure transducers suction and discharge servicing charging ports electric solenoid unloaders and a shaft seal reservoir for the 05G Twin Port compressor only The compressor raises the pressure and temperature of the refrigerant gas and forces it into the condenser tubes The clutch assembly provides a means of belt driving the compressor by the coach engine The suction and discharge service valves enable servicing of the compressor
10. To check the unloaders proceed as follows a Ensure that the compressor is fully loaded Heat the interior of the coach if necessary T 329 7 w wu Electric Unloader 7 Valve 8 Suction Service Valve Charging Port Suction Service Valve Clutch Oil Fill Plug Bottom Plate Oil Drain Plug Oil Level Sight Glass Oil Pump 10 O Ring Discharge Service Valve Service Port Figure 4 9 Model O5G Compressor b Connect manifold guages to the compressor 9 Slowly frontseat the suction valve until 26 psig shows on the suction guage The first unloader should energize check for magnetism at the unloader coil increasing suction pressure by 3 to 5 psig Slowly open the suction valve until the suction gauge reads 32 psig The first unloader should de energize decreasing suction pressure by 3 to 5 psig to show it is operating properly To check the second unloader continue to frontseat the suction valve until 21 psig shows on the suction guage The second unloader should energize check for magnetism at the unloader coil increasing suction pressure by 3 to 5 psig Slowly open the suction valve until the suction guage reads 28 psig The first unloader should de energize decreasing suction pressure by 3 to 5 psig to show it is operating properly Back seat the suction service v
11. 4 959 8 s 108 074 Ew quens uer 3e o ws rn 38 s wr 128 e 2892 16 1580 s iss 140 137 150 66 2629 1848 1843 15 es 2841 1976 1927 329 4 16 SECTION 5 ELECTRICAL SCHEMATIC DIAGRAMS 5 1 INTRODUCTION This section contains Electrical Schematic Diagrams covering the Models listed in Table 1 1 Contact your Carrier Transicold service representative or call the technical hot line at 800 450 2211 for a copy of the schematic for your specific model BOLS END SYMBOL IPTIO A WIRE GROUND AT T TEMPERATURE SENSOR GROUND STUD CONNECTION XXBPHV BY PASS HEAT VALVE CONDENSER CONNECTOR BUS INTERFACE POWER STUD xCB CIRCUIT BREAKER xxCB CIRCUIT BREAKER A CONNECTOR PIN CFRI CONDENSER FAN RELAY 1 CFR2 CONDENSER FAN RELAY 2 A NORMALLY OPEN CONTACT CM1 CONDENSER FAN MOTOR 41 CM2 CONDENSER FAN MOTOR 2 A NORMALLY CLOSED CONTACT CL LUTCH RELAY CSRI ONDENSER SPEED RELAY A DIODE DC F VER CONTROL CONNECTOR BUS INTERFACE DC VER CONTROL BOX CIRCUIT BREAKER 1 SPLICE CONNECTION DC VER CONTROL BOX CIRCUIT BREAKER 2 DC VER CONTROL BOX FAN RELAY LOW SPEED DE A VER EVAPORATOR CONNECTOR BUS INTERFACE DEMI VER EVAPORATOR MOTOR 1 DEM2 VER EVAPORATOR MOTOR 2 VER HEAT VALVE VER LIQUID LINE CONNECTOR BUS INTERFACE VER LIQUID SOLENOID VALVE PT SCHARGE PRESSURE TRANSDUCER R A VER RAM AIR CONNECTOR BUS INTER
12. Diagnostics 2 1 2 5 Discharge Pressure 2 3 Driver Control Box 4 13 Driver Display Panel 1 9 Driver Evaporator 4 14 Driver Evaporator 1 5 Driver Evaporator Air Filter 4 14 Driver Evaporator Blower 4 14 INDEX E Electrical Specifications Controls 1 10 Electrical Specifications Motors 1 10 Evacuation And Dehydration 4 4 Evaporator Assemblies 1 4 Evaporator Coils 1 13 Evaporator Fan Speed Selection 2 3 F Fan Motor Operation Sequence 2 4 Filter Drier 4 7 Fuse 1 11 H Heating 2 2 Heating Flow Cycle 1 12 High Pressure Switch 1 11 Hour Meter 2 5 Humidity Sensor 4 12 Introduction 1 1 L Liquid Line Solenoid 2 4 Logic Board 1 7 2 1 3 1 4 15 Low Pressure Transducer 1 11 Main Control Box 1 7 Main Evaporator Assembly 1 6 Main Evaporator Blower Assembly 4 12 Main Evaporator Or Heater Coil 4 13 Maintenance Schedule 4 1 Manifold Guages 4 2 Micrormate Control Panel 2 1 3 1 Modes Of Operation 2 2 Index 1 T 329 O Oil Charge 1 10 Oil Adding Charge 4 10 Operating Controls 1 9 Operating Instructions 2 1 P Parcel Rack Evaporator 4 14 Parcel Rack Evaporator 1 5 Pre Trip Inspection 2 1 Pressure Transducer 4 11 4 12 R Refrigerant Charge 1 10 4 6 Refrigerant Charge Removal 4 3 Refrigerant Leak Check 4 4 Refrigerant Removal From Compressor 4 3 Refrigerant Service Connections 4 5 Refrigeration System Components 1 10 Relay Board 1 8
13. Energizes evaporator fans in low speed Energizes evaporator fans in high speed not energized in low speed Energizes condenser fans in low speed Energizes condenser in high speed not energized in low speed Energizes the A C clutch and liquid line solenoid valve Energizes unloader 1 Energizes unloader 2 Energizes fresh air damper Energizes reheat coolant valve Energizes the fault light output Energizes the boost pump Energizes the driver s liquid line solenoid valve b Connectors JA JB JC Relay board connector communication to system Boost pump Ribbon Cable Logic Module to Relay Board c Fuses F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 T 329 Fresh air relay Unloader 1 relay Evaporator fan motor relay Fault light out relay Unloader 2 relay Heater relay Clutch relay Spare Condenser motor fan relay Boost pump relay D2 D6 D26 D30 D51 D54 D57 D63 D66 D69 D72 D17 D38 D18 D68 D47 D61 D90 D77 D31 D83 Evaporator fans output active high speed Evaporator fans output active Condenser fans output active Condenser fans on high speed A C clutch and liquid line solenoid valve output active Unloader 1 output active Unloader 2 output active Heat output active RCV Fault output active Boost pump output active Driver s liquid line solenoid valve active Fresh air relay fuse out Unloader 1 relay fuse out Evaporator fan motor relay fuse
14. Replacing High Pressure Switch 4 7 T 329 INDEX S Safety Devices 1 11 Safety Summary General i Schematic Diagram 5 3 5 5 5 6 Self Diagnostics 3 1 Servicing Motor Brushes 4 12 Shaft Seal Reservoir 4 8 Suction and Discharge Service Valves 4 2 Suction Pressure 2 3 Superheat Check Measure 4 8 System Parameters 2 4 System Pumpdown 4 2 System Service 4 1 System Shutdown 2 1 System Start up 2 1 T Temperature Control 2 2 2 3 Temperature Pressure Chart 4 16 Temperature Sensor 4 11 Thermostatic Expansion Valve 4 7 Troubleshooting 3 1 U Unloader Control 2 2 V Vent Mode 2 2 Index 2 2 Carrier Carrier Transport Air Conditioning Borerumbachankoad A United Technologies Company York PA 17402 USA Carrier Transicold Division Tel 1 800 673 2431 Carrier Corporation Fax 1 717 764 0401 Transport Air Conditioning Group P O Box 4805 Syracuse N Y 13221 0 5 www carrier transicold com A member of the United Technologies Corporation family Stock symbol UTX TRANSICOLD 2005 Carrier Corporation Printed in U 5 A 0805
15. T 329 4 11 1 Replacing 4 6 Pump down low side of the unit Refer to paragraph 4 4 the Expansion Valve See b insulation Presstite from expansion valve ulb c Loosen retaining straps holding bulb to suction line and detach bulb from the suction line d Loosen flare nut on equalizer line and disconnect equalizer line from the expansion valve e Remove capscrews and lift off power head and cage assemblies and gaskets f Check clean and remove any foreign material from the valve body valve seat and mating surfaces NOTE Do not adjust the new replacement expansion valve Valves are preset at the factory g Using new gaskets install new cage and power head assemblies provided with repair kit 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 and insulate both with Presstite Ensure that retaining straps are tight See Figure 4 7 Connect equalizer line to the expansion valve j Evacuate and dehydrate Refer to paragraph 4 6 Open filter drier inlet valve liquid line service valve and all service valves l ae the coach for approximately 30 minutes on fast idle m Check refrigerant charge Refer to paragraph 4 7 1 n Check superheat Refer to paragraph 4 11 2 Suction Line end view TXV Bulb C
16. Table 3 1 Error Codes cox wag Program Memory Display program memory failure 3 2 SYSTEM ALARMS 3 2 2 Activation 3 2 1 Alarm Codes When alarms are detected they are placed in an alarm The Micromax Logic Board continuously monitors queue in the order at which they initiated unless the system parameters and will generate an ALARM if a alarm is already present Each alarm recorded will also parameter exceeds preset limits Alarms are indicated capture an evaporator hour meter reading and the controller will respond in accordance with the corresponding to the activation time If the AUTO key is information provided in Table 3 2 The alarm codes can pressed while an alarm is displayed the activation time be read by counting the number of times that the Logic capture will be shown Board CODE LED see Figure 1 9 flashes Each alarm code is a two digit number the first set of flashes is the 3 2 3 Alarm Queue first digit and after a slight pause the second set of flashes is the second digit The alarm queue consist of 10 alarm locations When m the alarm queue is full the Logic Board will take the The Micromate control panel display will indicate alarms required action but the alarm will not be recorded When with the code A or i where is an active alarm this situation occurs an Alarm Queue Full alarm will be prefix i is an inactive alarm prefix and is the alarm generated When the al
17. Transport Air Conditioning OPERATION AND SERVICE for 68G5 105 SERIES MCI J4500 COACH with MICROMAX Air Conditioning Unit T 329 Rev TRANSICOLD OPERATION AND SERVICE MANUAL TRANSPORT AIR CONDITIONING EQUIPMENT Model 68G5 105 Series for MCI J4500 Model Coach with Micromax 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 that must be understood and applied during operation and maintenance of the equipment covered herein The general safety notices are presented in the following three sections labeled First Aid Operating Precautions and Maintenance Precautions A listing of the specific warnings and cautions appearing elsewhere in the manual follows the general safety notices FIRST AID An injury 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 evaporator and condenser fans No work should be performed on the unit until all circuit breakers and start stop switches are turned off and the 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 e
18. 1 Resistor 2 Heat Valve Control Connector 3 Control Box 4 Ground Stud 5 Power Stud 6 Controller Interface Connector DC3 7 Driver Defrost Connector DC1 12 11 10 8 Driver Defrost Connector DC2 9 Circuit Breaker 10 Evaporator Fan Relay High Speed B 11 Evaporator Fan Relay High Speed A 12 Evaporator Fan Relay Medium Speed 13 Evaporator Fan Relay Low Speed 14 Heat Valve Controller Figure 1 4 Driver Control Box T 329 1 2 3 4 5 6 7 8 Access Panel Fan and Motor Electrical Connector Nameplate Air Bleed Valve Solenoid Valve and Coil Thermal Expansion Valve RAM Actuator Suction Outlet Connection Liquid Inlet Connection Side Access Panel Top Access Panel Thermal Expansion Valve Evaporator Coil Assembly RAM Air Door Liquid Inlet Connection Size 11 16 ORS Suction Outlet Connection 1 7 16 ORS Service Port Condensate Drain Connections Air Filter Evaporator Coil Assembly Heater Coil Assembly 11 Fan and Motor Motor Mount Bracket Condensate Drain Connection Relay Thermostat Not supplied by Carrier Fig
19. Blade missing or broken 3 3 5 Control System Malfunction Will not control Sensor or transducer defective Relay s defective Microprocessor controller malfunction Logic Board J3 connector unplugged 3 3 6 No Evaporator Air Flow Or Restricted Air Flow Air flow through coil blocked Coil over Dirty 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 7 Expansion Valve Malfunction Low suction pressure with high Low refrigerant charge superheat Wax oil or dirt plugging valve orifice Ice formation at valve seat Power assembly failure Loss of bulb charge Broken capillary tube Side to side differ Wax oil or dirt plugging valve orifice Ice formation at valve seat Power assembly failure Loss of bulb charge Broken capillary ence Warm Coil 3 3 8 Heating Malfunction Insufficient 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 No Heating Check Tighten Replace Check Check Replace Defrost coil Clean Cl
20. Suction and discharge access 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 Transducers convert refrigerant pressures into electrical signal inputs which are sent to the main controller The high pressure switch HPS is a normally closed switch its 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 coach For more detailed information on the compressor refer to manual number 62 02756 or 62 11052 05G Twin Port 1 2 3 Evaporator Assemblies The evaporator assemblies include a driver evaporator assembly See Figure 1 5 a main evaporator assembly See Figure 1 7 and may include two parcel rack evaporator assemblies See Figure 1 6 The driver evaporator assembly includes an evaporator coil assembly a thermal expansion valve a heater coil assembly an evaporator heat valve EHV two fan and motor assemblies an air filter and two condensate drain connections The evaporator heat valve EHV for the driver evaporator is installed in the piping outside the evaporator assembly In addition the driver evaporator has an actuator which controls the outside RAM air damper upon receipt of signal from the main controller The main evaporato
21. This option is only available in logic module software revisions 1 9 and newer and drivers display software revision 1 3 and newer Otherwise P35 will not be active and set point tempera ture 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 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 T 329 2 6 SECTION 3 TROUBLESHOOTING CAUTION Do not under any circumstances attempt to service the microprocessor Should a problem develop with the microprocessor replace it 3 1 SELF DIAGNOSTICS that the Logic Board STATUS and CODE see A self test is performed by the Micromax Logic Board Figure 1 9 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 ER where is the error prefix and is the error error codes can be read by counting the number of times number
22. 1 43 MANIFOLD GAUGES 4 2 4 3 1 Installing R 134a Manifold Gauge 4 2 44 PUMPING THE SYSTEM DOWN OR REMOVING THE REFRIGERANT CHARGE 4 2 4 4 1 System 1 2 2 4 2 4 4 2 Removing the Refrigerant Charge 4 3 4 4 8 Refrigerant Removal From An Inoperative Compressor 4 3 4 4 4 Pump Down An Operable Compressor For Repair 4 3 45 REFRIGERANT LEAK CHECK 4 4 4 6 EVACUATION AND DEHYDRATION 4 4 4 6313 Generali 4 4 4 6 2 Preparations iue metre dels e ee uie neta eh E 4 4 4 6 3 Procedure for Evacuation and Dehydrating System 4 4 47 ADDING REFRIGERANT TO 6 4 6 4 7 1 Checking Refrigerant Charge 4 6 4 7 2 Adding Full Charge 2 4 6 4 7 8 Adding Partial Charge 4 6 4 8 CHECKING FOR NONCONDENSIBLES 4 6 4 9 CHECKIN
23. 10 21 11 91 10 89 12 66 11 91 13 61 12 93 14 42 i With an accurate temperature gauge measure the condenser inlet air temperature NOTE Do not use a temperature gun as it measures surface temperature and not air temperature T 329 1 If the actual discharge pressure is higher than the discharge pressure range the system may be over charged 2 If the actual discharge pressure is lower than the discharge pressure range the system may be under charged 3 If the actual discharge pressure is in the discharge pressure range the system charge is adequate NOTE Many system related problems will effect system pressures Use General System Troubleshooting Procedures Table 3 3 3 to determine other possible causes before adding or removing refrigerant 4 7 2 Adding Full Charge a a and dehydrate system Refer to paragraph 4 6 b Place appropriate refrigerant cylinder on scales and connect charging hose from container to filter drier inlet valve Remove air from hoses c Note weight of refrigerant and container d Open liquid valve on refrigerant container Midseat filter drier inlet valve and allow refrigerant to flow into the unit Refer to paragraph 1 3 for correct charge e When drum weight scale indicates that the correct charge has been added close liquid line valve on drum and backseat the filter drier inlet valve 4 7 3 Adding Partial Charge NOTE Refrigerant charge is critical when adding ch
24. 7 Adding Oil to Service Replacement Compressor 4 10 4 12 8 Removing Oil from the Compressor 4 10 4 13 TEMPERATURE SENSOR 4 11 4 14 SUCTION AND DISCHARGE PRESSURE TRANSDUCER CHECKOUT 4 12 4 15 REPLACING SENSORS AND TRANSDUCERS 4 12 4 16 SERVICING MAIN EVAPORATOR BLOWER ASSEMBLY 4 12 4 17 ACCESSING MAIN EVAPORATOR MOTOR BRUSHES 4 12 4 18 SERVICING MOTOR BRUSHES 4 12 4 19 SERVICING THE MAIN EVAPORATOR AND HEATER 4 13 4 20 REMOVING THE CONDENSER ASSEMBLY 4 13 4 21 SERVICING THE CONDENSER COIL 4 13 4 22 SERVICING THE CONDENSER 4 13 4 23 SERVICING THE DRIVER CONTROL 4 13 4 24 SERVICING THE DRIVER EVAPORATOR 4 14 4 24 1 Access Cover Removal 4 14 4 24 2 Blower Removal 4 14 4 24 3 Air filter 2 4 14 4 24 4 Removal of Evaporat
25. Control 1 7 1 2 5 System Operating Controls And Components 1 9 1 2 6 Other Carrier Supplied 1 1 9 1 38 REFRIGERATION SYSTEM COMPONENT SPECIFICATIONS 1 10 1 4 ELECTRICAL SPECIFICATIONS WOUND FIELD MOTORS 1 10 1 5 ELECTRICAL SPECIFICATIONS MAIN CONTROLLER INPUT SENSORS AND TRANSDUCERS renes eret pU LU DR VOIR WIR IUS Ca SI ee Ses 1 10 1 6 SAFETY DEVICES veste e HER RI 1 11 1 7 HEATING ENGINE COOLANT FLOW CYCLE 1 12 18 AIR CONDITIONING REFRIGERANT 1 13 OPERATION gere IRIURE ERR RE ERR ERE dae pen emen da ru RU 2 1 21 STARTING STOPPING AND OPERATING INSTRUCTIONS 2 1 2 71 Power to Eogic Boards a pec RD Peas Ps bea ee eased dan 2 1 2 2 e E eM LLL VE A LE 2 1 2 1 3 Self Test and Diagnostics Check for Errors and or Alarms 2 1 2 1 4 Stoppilig secos telufinekcsceE R4 yl 2 1 2 2 PRE TRIP INSPECTION eR ER Dm ER E RR RU Ne REY RE nee as 2 1 2 3 OF OPERATION xe petite ea wed eo eee t see ee eek 2 2 2 31 Temperature 2 2 2 3 2 Cooling
26. DISCHARGE SERVICE TO DISCHARGE OR VALVE STEM CAP VALVES FROM SUCTION LIN The suction and discharge service valves See Figure 4 1 used on the compressor are equipped with mating flanges for connection to flanges on the IN SS compressor These valves are provided with a double seat and a gauge connection which allows servicing of lt lt 55 T US the compressor and refrigerant lines Turning the valve stem counterclockwise all the way PORT TO VALVE out will backseat the valve to open the suction or COMPRESSOR STEM discharge line to the compressor and ACCESS VALVE gauge connection In normal operation the valve is ACCESS VALVE CAP R 134a backseated to allow full flow through the valve The CERS valve should always be backseated when connecting Service Val the service manifold gauge lines to the gauge ports Service Valve vave gt Frontseated Backseated Turning the valve stem clockwise all the way forward clockwise counterclockwise will frontseat the valve to close off the suction or 4 ihe compressor and epemtne Figure 4 1 Suction or Discharge Service Valve 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 line is open to both the compressor and the gauge connection 4 1 T 329 4 3 MANIFOLD GAUGES Th
27. 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 Ambient Temperature This value is the outside temperature measured by 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 Superheat Not used Analog Set Point Not used Temperature A C Control Window This is the number of degrees F above setpoint at which the unloaders will be 1 both energized This value be modified between 0 and 10 degrees F The default value is 1 degree F P10 A C Control Window This is the number of degrees above AC control 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 degrees above AC control window two at which the evaporator fan speed will be set
28. PORT CONDENSER ASSEMBLY PARCEL EVAPORATOR PARCEL RACK ASSEMBLY LIQUID LINE MAIN LIQUID LINE SOLENOID VALVE SOLENOID VALVE FILTER DRIER DISCHARGE gt CHECK VALVE i SERVICE CONDENSER PORT PARCEL EVAPORATOR ASSEMBLY PLUG LIQUID LINE KING SERVICE DISCHARGE LINE SERVICE VALVE PORT SERVICE VALVE SUBCOOLER SUCTION LINE DISCHARGE LINE SERVICE PORT COMPRESSOR Figure 1 12 Air Conditioning Refrigerant Flow Diagram 329 1 14 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 a 24 vdc power for the microprocessor electronics is supplied through the bus interface b 24 vdc 150 amp power from a fuse in the battery compartment supplies power for the clutch compres sor 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 MICROMATE CONTROL PANEL It eae the system be started in the automatic mode 1 Tostart t
29. Wait 5 minutes to verify that vacuum olds Once vacuum is maintained recharge low side with R 134a to 20 to 30 PSIG by admitting vapor from the refrigerant cylinder Backseat compressor service valves and disconnect manifold gauge set Discharge Service Valve and Port Suction Service Valve and Port Manifold Gauge Set 4 Vacuum Pump 5 Reclaimer 6 Refrigerant Cylinder 7 Thermistor Vacuum Gauge Figure 4 3 Compressor Service Connections 4 4 4 Pump Down Operable Compressor For Repair To service an operable compressor pump the refrigerant into the condenser coil as follows a Install manifold gauge set See Figure 4 3 b Unplug the suction pressure transducer SPT c Frontseat the compressor suction service valve by turning clockwise Start the unit and run in cooling until 10 hg 0 69 BAR of vacuum is reached Shut the system down and tag out system power source Frontseat the compressor discharge service valve and wait 5 minutes to verify vacuum is maintained If the pressure rises above vacuum open the compressor discharge service valve and repeat steps c and d until a vacuum is maintained f Service or replace components as required and leak check the compressor g Using refrigerant hoses designed for vacuum service connect a vacuum pump to center connection of manifold gauge set Evacuate system to 500 microns Close off pump valve isolate vacuum gauge and stop pump Wai
30. displayed press the DOWN arrow key to scroll through the list from the first to the last parameter or press the UP arrow to scroll from the last to 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 P1 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 Enter the diagnostic mode by pressing the UP and DOWN arrow keys simultaneously for 3 seconds En ter the test mode immediately by pressing the COOL button five times If control has no cool button usethe FRESH AIR button b In the test mode the display will read T where indicated the test number that is currently run ning c The initial indication will be TOO 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 next test 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 1 d To terminate testing press the 0 key Table 2 1 Controller Test List TOO of T05 Compressor amp Liquid On TOS T12 Spare Motor Input On Floor Blower Table 2 2 Parameter Codes CODE CODE
31. eight screws holding the panel in place Remove and service the control box by performing the following procedure T 329 HEADLIGHT DRIVER CONTROL BOX Figure 4 10 Removing Driver Control Box Turn main battery disconnect switch to OFF position and lock Remove the power wire from the power stud and the connector from the box Remove the 1 4 inch capscrew at the upper right cover of the box Pull the box laterally approximately 3 4 inch to the right to remove it from the pocket d Rotate box counterclockwise 90 degrees as shown in Figure 4 10 and carefully lift the box out Repair or replace defective components as necessary Re install the driver control box by reversing the above procedure 4 24 SERVICING THE DRIVER EVAPORATOR 4 24 1 Access Cover Removal a Remove stepwell access cover and disconnect 2 inch flex hose adapter Using a flat screwdriver unfasten three 1 4 turn fasteners from access cover on driver evaporator assembly b Open driver storage compartment and remove plug in sheet metal With screwdriver unfasten the last 1 4 turn fastener e Draw access cover towards the rear and slide to the right 4 24 2Blower Removal a Disconnect plugs and speed control from the blower b Undo latch and push the blower towards the rear c Drop the blower down and remove 4 24 3 Air filter Removal a With the access cover removed
32. evaporators circuit breakers protect those circuits During a high current condition the breaker or OEM fuse may open When power is removed from a device a breaker alarm willbe generated c Ambient Lockout The ambient temperature sensor located in the condenser section measures the condenser inlet air temperature When the temperature is below the cut out set point the compressor is locked out until the temperature rises above the cut in setting The set points will be programmed to cut out at 25 F 3 9 C and cut in at 35 F 1 7 C This setting protects the compressor from damage caused by operation at low temperatures T 329 1 7 HEATING ENGINE COOLANT FLOW CYCLE Heating circuit components furnished by Carrier Transicold include heater cores and an evaporator heat valve EHV for the main evaporator assembly Components furnished by the coach manufacturer include auxiliary heater and engine water pump hand valves and Y type strainers a coolant bypass heat valve and a driver s heat valve The main controller automatically controls the EHV valves during heating and reheat cycles to maintain required temperatures inside the coach Engine coolant glycol solution is circulated through the heating circuit by the engine and auxiliary water pumps When the evaporator heat valve solenoid is de energized the valve will open to allow engine coolant to flow through the heater coil See Figure 1 11 The valve is norm
33. out Fault light out relay fuse out Unloader 2 relay fuse out Heater relay fuse out Clutch relay fuse out Unloader 1 fuse out Condenser motor fan relay fuse out Boost pump relay fuse out Figure 1 9 Relay Board 1 8 Defrost Fan Speed Up Increase Selection Down Decrease Selection RANSICOLD Display On Off 6 Temperature Inside Outside Defrost Heat Control Fresh Air Automatic Control Parcel Rack On Off 1 x 174 Fan Speed Figure 1 10 System Operating Controls upper left hand switch panel 1 2 5 System Operating Controls And Components There are five controls on the driver s station which are located on the dashboard to the left of the steering wheel They affect the operation of the Carrier supplied equipment covered by this manual These controls include two rotating switches two rocker switches and the Micromate Control Panel The first rotating switch is the Defrost Fan Speed Switch Figure 1 10 This switch controls the driver evaporator blower motor speed The second rotating switch is the Heat Control Switch Figure 1 10 This switch controls the driver evaporator coolant valve Thethird control is the rocker switch for the Parcel Rack This switch will activate the parcel rack evaporator blowers The forth control is the rocker switch for the Auxiliary Heater This switch will activate the system to provide additional heat to engine coolant 1 9 The
34. out of the way f Remove the evaporator electrical panel assembly g Remove the liquid line 3 connection points and the discharge line 2 connection points that pass thru the evaporator and connect to the evaporator h Disconnect and remove the suction line i Disconnect and remove the heater hoses j Remove the door frame surrounding the evaporator enclosure k Remove the four bolts that secure the coil bracket to the drain pan Leave the coil bracket bolted to the evaporator coil until the coil has been removed from the coach WARNING When moving the coil care must be taken to avoid personal injury because of the weight of the coil Brace the top of the coil hold it in position m Remove the four bolts that secure the top of the coil to the evaporator housing n Rotate the top of the coil till the coil is horizontal and slide out of the evaporator housing o Re install by performing the above procedure in reverse 4 20 REMOVING THE CONDENSER ASSEMBLY a Remove two side access panels from rear of the last baggage bay b Remove and reclaim the entire refrigerant charge Refer to paragraph 4 4 2 c Turn main battery disconnect switch to OFF position and lock d Disconnect all electrical leads to the module e Disconnect refrigerant lines to the module f Remove the door latch stud to the right side of the condenser compartment g Remove the front panel and the eight screws faste
35. paragraph 4 7 4 9 CHECKING AND REPLACING HIGH PRESSURE CUTOUT SWITCH 4 9 1 Replacing High Pressure Switch a The high pressure switch is equipped with schrader valve to allow removal and installation without pumping the unit down b Unplug the wiring from the switch c Check switch operation Refer to paragraph 4 9 2 d Replace switch if it does not function as outlined below Refer to paragraph 4 9 2 4 9 2 Checking High Pressure Switch AX WARNING Do not use a nitrogen cylinder without a pressure regulator WARNING Do not use oxygen in or near a refrigeration system as an explosion may occur Remove switch from unit All units are equipped with schrader valves at the high pressure switch connection b Connect an ohmmeter across switch terminals If the switch is good the ohmmeter will indicate continuity indicating that the contacts are closed Cylinder Valve and Gauge Pressure Regulator Nitrogen Cylinder Pressure Gauge 0 to 400 psig 0 to 2 8 mPa Bleed Off Valve 1 4 inch Connection Figure 4 5 Checking High Pressure Switch c Connect switch to a cylinder of dry nitrogen See Figure 4 5 4 7 d Set nitrogen pressure regulator higher than cutout point on switch being tested Refer to paragraph 1 3 e Open cylinder valve Slowly open the regulator valve to increase the pressure until it reaches cutout point The switch should open which is indicated by an infinity reading
36. positive pressure of 1 0 psig 0 07 BAR 5 Front seat both manifold gauge set hand valves and disconnect from cylinder The gauge set is now ready for use b Connecting Manifold Gauge Hose 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 2 items 5 and 6 to the access valve 3 Turn the 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 c Removing the Manifold Gauge Set 1 While the compressor is still ON 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 in the manifold gauge set be sure set is brought to 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 4 4 PUMPING THE SYSTEM DOWN OR REMOVING THE REFRIGERANT CHARGE N
37. 2 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 P27 2 Hours This is the value of evaporator fan hours low P23 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 one degree in crements by using the arrow keys P29 Relay Module Voltage This is the voltage being supplied to the relay module P30 e Board Software This is the software version of the logic board ersion 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 8 4 P35 Default Display Tem This value determines what temperature value the driver s display will show as perature a default When the value is OFF set point temperature is displayed When the value is ON return air temperature is displayed
38. ATIONS MAIN CONTROLLER INPUT SENSORS AND TRANSDUCERS a Suction and Discharge Pressure Transducer Supply Voltage 4 5 to 5 5 vdc 5 vdc nominal Input Range 6 7 to 450 psig 0 05 to 30 62 BAR Output Voltage vdc 0 0098 x psig 0 4659 See Table 4 4 for calculations b Temperature Sensors Input Range 52 6 to 158 F 47 to 70 C Output NTC 10K ohms at 77 F 25 C See Table 4 3 for calculations 1 6 SAFETY DEVICES System components are protected from damage caused by unsafe operating conditions with safety devices Carrier Transicold supplied safety devices include a high pressure switch HPS low pressure switch LPS circuit breakers and fuses a Pressure Switches High Pressure Switch HPS During the A C mode compressor operation will automatically stop if the HPS switch opens due to an unsafe operating condition Opening HPS de energizes through the controller the compressor clutch shutting down the compressor The high pressure switch is installed in the center head of the compressor Low Pressure Transducer If the control monitors a pressure less than 10 psig R 134a by the suction pressure transducer mounted on the compressor the system will be shut down for at least one minute b Fuses and Circuit Breakers The Relay Board is protected against high current by an OEM supplied 30 amp fuse Independent 70 amp evaporator 100 amp condenser 40 amp driver s evaporator and 70 amp parcel
39. AY 1 POWER STUD CM10L TOME UNDE 9 5 COND SPEED RELAY 35 EVAP FAN LOW SPEED JA 5 EVAP FAN HIGH SPEED JA FRESH AIR oN ro DRIVER LIQUID SOLENOID VALVE JA i r UNLOADER 1 ZN ro UNLOADER 2 CLUTCH NC 4 ro HEAT VALVE JA m i po F4 SA 9c FAULT LIGHT OUT JA SOURCE BOOST PUMP SOURCE BOOST PUMP OUT JB JB JB q 10 15 GROUND STUD See Figure 5 1 for legend and symbols Figure 5 5 Wiring Schematic Relay Board and External Contactors 12 00486 00 5 5 T 329 2 B E 1 t t y g BEBE iA ROS i H 3 amp lt 2 BE i g ibe 5 8 8 Bos Figur Contact vehicle nufac a epectiic diagrami T 329 5 6 Air Conditioning Refrigerant Cycle 1 13 Alarm 2 4 3 1 Alarm Clear 3 1 Alarm Codes 3 1 Alarm Queue 3 1 Ambient Lockout 1 11 Checking For Noncondensibles 4 6 Checking High Pressure Switch 4 7 Checking Refrigerant Charge 4 6 Circuit Breaker 1 11 Clutch 2 4 Compressor 1 3 1 4 Compressor Oil Level 4 10 Compressor Re install 4 9 Compressor Removal 4 8 Compressor Unloaders 4 9 Condenser Assembly 1 2 4 13 Condenser Coil 4 13 Condenser Fan 2 3 Condenser Motor 4 13 Cooling Mode 2 2 D
40. FACE EVAPORATOR CONNECTOR BUS INTERFACE RH EVAPORATOR FAN RELAY HIGH SPEED RL EVAPORATOR FAN RELAY LOW SPEED V EVAPORATOR HEAT VALVE SV EVAPORATOR LIQUID SOLENOID VALVE EVAPORATOR MOTOR FUSE CUSTOMER SUPPLIED HIGH PRESSURE SWITCH HUMIDITY SENSOR PARCEL RACK CONNECTOR BUS INTERFACE PARCEL RACK MOTOR CURB SIDE ROAD SIDE PARCEL RACK A C SWITCH PARCEL RACK SOLENOID VALVE RAM AIR SOLENOID DRIVER RAM AIR SOLENOID PASSENGER SUPPLY AIR THERMOSTAT ROAD SIDE ONLY D FUSE MOTOR LSV PRESSURE SENSOR 2 PRESSURE SWITCH TEMPERATURE SENSOR RESISTOR DMM Ux AUTO RESET BREAKER THERMAL OVERLOAD NC X CU OU IL ID OX TD DD DD D n fn CO QOO OQ CD X LI THERMAL OVERLOAD NO SUCTION PRESSURE TRANSDUCER TEMPERATURE SENSOR CURB TEMPERATURE SENSOR ROAD RELAY N P E USED UNLOADER SOLENOID VALVE 1 UNLOADER SOLENOID VALVE 2 MODULE NDICATES THESE COMPONENTS ARE SUPPLIED BY MOTOR COACH INDUSTRIES CONNECTOR SET SPDT SWITCH NDICATES LED NDICATES WIRE CONNECTION TE INSIDE MODULE WIRES ARE FACTORY WIRED DULE TO MODULE WIRE CONNECTIONS ARE FIELD WIRED Figure 5 1 Electrical Schematic Diagram Legend and Symbols Based On Drawing No 62 10981 Rev 5 1 T 329 MAIN EVAPORATO
41. G AND REPLACING HIGH PRESSURE CUTOUT SWITCH 4 7 4 9 1 Replacing High Pressure 4 7 4 9 2 Checking High Pressure Switch 4 7 T 329 ii TABLE CONTENTS Continued Section Page 4 10 FILFER DRIER ace Ser eee a e ee EN Seeds 4 7 4 10 1 To Check Filter 4 7 4 10 2 To Replace Filter Drier 4 7 4 11 THERMOSTATIC EXPANSION VALVE 1 4 7 4 11 1 Replacing the Expansion 4 8 4 11 2 Check Measure 4 8 4 12 MODEL 05G COMPRESSOR MAINTENANCE 4 8 4 12 1 Shaft Seal Reservoir 1 1 22 22 4 8 4 12 2 Removing the 4 8 4 12 3 Re installing the Compressor 4 9 4 12 4 Compressor Unloaders 4 9 4 12 5 Compressor Oil Level 4 10 4 12 6 Adding Oil with Compressor in System 4 10 4 12
42. OTE To avoid damage to the earth s ozone layer use a refrigerant recovery system whenever removing refrigerant 4 4 4 System Pumpdown To service or replace the filter drier expansion valve evaporator coil or suction line pump the refrigerant into condenser coil as follows a Install manifold gauge set Refer to paragraph 4 3 b Startthe unit and allow it to run in the cool mode for 15 to 20 minutes c Unplug the suction pressure transducer SPT NOTE The following procedure may have to be repeated several times to maintain the 0 to 2 psig 6 9 kPa pressure depending upon amount of refrigerant absorbed in the oil Frontseat the liquid line King valve by turning clockwise Start system and run in cooling Stop the unit when the suction pressure reaches 1 psig 0 07 BAR Frontseat close suction service valve to trap the refrigerant in the high side of the system between the compressor suction service valve and the filter drier inlet valve The low side of the system will now be at 1 psig 0 07 BAR pressure and ready for servicing f Service or replace the necessary component on the low side of the system Leak check connections Refer to paragraph 4 5 h Evacuate and dehydrate the low side Refer to paragraph 4 6 i Reconnect the suction pressure transducer SPT j the low pressure alarm Refer to paragraph 3 2 1 4 4 2 Removing the Refrigerant Charge Connect a refrigerant recover
43. R CONDENSER iho rye 24VDC e 55 CMIOL 1 2 2 ow CM20L rH gt A 6 LSV 5 05 PSV 70A gt B ED 24VD0 O 0 A 1 2 BE DRIVER CONTROL BOX DRIVER EVAPORATOR do 30A DC DE gt 1 Pos 2400 S gt e bo 30 87 gt 2 EFRHB EFRHB 87A 30 H 87 3 R 2 0 OHMS 4 ANA EFRM x 87 EFRHA x01 062 DLSV gt A gt B PARCEL RACK ROAD SIDE PARCEL RACK CURB SIDE PR PR 3904 5 Be PR PR 570 2 AO 85 geo 85 GRD STUD PT GRD STUD gt A a on e bs THERMOSTAT See NO TAG for legend and symbols Figure 5 2 Electrical Schematic Diagram Sheet 1 of 2 Based On Drawing No 62 10981 Rev T 329 5 2 329
44. Reserved for the manufacturer Invert H2O When this configuration is removed the logic for the water temperature switch will be inverted Voltage When this configuration is removed the voltage selection will be changed from 12 to 24 vdc Security Reserved for the manufacturer M Psig Bars When this configuration is removed the display will indicate pressures in bars i When not removed the display will indicate pressures in psig E F J K L N C F When this configuration is removed the display will show temperatures in F When not removed the display will show temperatures in C PI Reheat When this configuration is removed reheat mode will use the PI algorithm to vary the duty cycle of the heat valve If it is not removed the heat valve will be on constantly 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 4 15 T 329 Table 4 6 R 134a Temperature Pressure Chart Temperature Pressure Lees hg Kg cm Bar C Kg cm2 e 30 1 Carper par ance 5 o 278 19 ce p s 67 176 52 2 9 ss 042 8 os 182 0 Temperature 50 10 455 320 314 LL ras ICON e RETO IC amp e2 29 9020 o 65 046 945
45. ally open so that if a failure occurs the system will still be able to supply heat DRIVER S HEAT VALVE AIR BLEED I VALVE DRIVER Y HEATER STRAINER CORE HEAT VALVE MAIN HEATER CORE HAND VALVE DRAIN VALVE STRAINER HAND VALVE A AUXILIARY HEATER BYPASS HEAT VALVE INDICATES COMPONENTS FURNISHED ENGINE WATER PUMP o ENGINE BY THE COACH MANUFACTURER Figure 1 11 Heating System Flow Diagram T 329 1 8 AIR CONDITIONING REFRIGERANT CYCLE When air conditioning cooling is selected by the main controller the unit operates as a vapor compression system using R 134a as a refrigerant The main components of the system are the reciprocating compressor air cooled condenser coil subcooler filter drier thermostatic expansion valves liquid line solenoid valves and evaporator coils See Figure 1 12 The compressor raises the pressure and the temperature of the refrigerant and forces it through the discharge line and the check valve into the condenser tubes condenser fan circulates surrounding air which is at a temperature lower than the refrigerant over the
46. alve remove the guage s to resume normal operation 4 12 5 Compressor Level o The compressor should be fully loaded six cylinder operation the unit should be fully charged and the compressor crankcase should be warm to the touch Start the unit and allow the system to stabilize Check the oil sight glass on the compressor to ensure that no foaming of oil is present after 20 minutes of operation If oil is foaming excessively after 20 minutes of operation check the refrigerant system for T 329 4 flood back of liquid refrigerant Correct this situation before proceeding Check the level of oil in oil level sight glass immediately after shutting down the compressor The lowest level visible should be at the bottom of the sightglass and the highest level should be at the middle of the sight glass See Figure 4 9 12 6 Adding Oil with Compressor in System Two methods for adding oil are the oil pump method and closed system method 4 a 4 a b d 2 NOTE Special care must be taken when working with POE oil that is used with HFC refrigerants such as R 134a as POE oil is very hygroscopic POE oil will easily absorb water Do not leave POE oil containers open to the atmosphere 12 6 1 Oil Pump Method One compressor oil pump that may be purchased is a Robinair part no 14388 This oil pump adapts to one U S gallon 3 785 liters metal refrigeration oil containe
47. ant container on weight scales Refer to paragraph 4 7 Reclaimer Manifold Guage Set Thermistor Vacuum Guage Vacuum Pump Refrigerant Cylinder Evaporator Service Port Liquid Line King Valve and Service Port Discharge Service Port Discharge DRIVER SOLENOID ee VALVE mmm Suction TXV BULB ERNE RAR RARER DRIVER EVAPORATOR SERVICE PORT ASSEMBLY 7 TXV BULB J PASSENGER EVAPORATOR ASSEMBLY PARCEL EVAPORATOR PARCEL RACK ASSEMBLY LIQUID LINE MAIN LIQUID LINE SOLENOID VALVE SOLENOID VALVE FILTER DRIER DISCHARGE CHECK CONDENSER lt VALVE ASSEMBLY SERVICE SIGHT GLASS CONDENSER gt gt SUBCOOLER PARCEL EVAPORATOR ASSEMBLY PLUG SERVICE 1 DISCHARGE LINE PORT SERVICE VALVE SUCTION LINE DISCHARGE LINE SERVICE PORT 8 COMPRESSOR Figure 4 4 Refrigerant Service Conne
48. aporator air flow or restriction Heating system Reheat coolant valve stuck open 3 3 3 Abnormal Pressures High discharge pressure Discharge transducer failure 22 Refrigerant overcharge 4 4 Noncondensable in system Check Condenser motor failure Check Condenser coil dirty Clean Low discharge pressure Discharge transducer failure See Note Compressor valve s worn or broken See bou 1 2 Low refrigerant ae High suction pressure Compressor valve s worn or broken See mas 1 2 Low suction pressure Suction service valve partially closed Open Filter drier inlet valve partially closed Check Open Filter drier partially plugged 4 10 Low refrigerant charge 4 7 Expansion valve malfunction 3 3 7 Restricted air flow 3 3 6 Suction transducer failure Replace Suction and discharge pressures Compressor valve defective See Table 1 2 tend to equalize when system is operating 3 3 4 Abnormal Noise Or Vibrations Compressor Loose mounting hardware Check Tighten 329 Worn bearings 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 4 See Table 1 2 See Table 1 2 3 3 7 4 12 6 Check Check Adjust Clean Table 3 3 General System Troubleshooting Procedures Continued INDICATION REFERENCE 3 3 4 Abnormal Noise Or Vibrations Continued Condenser or evaporator fans Loose mounting hardware Defective bearings Blade interference
49. arge to the unit do not add any more charge to the system after bubbles have been eliminated from the sight glass a Start the vehicle engine and allow the system to stabilize Refer to 4 7 1a to f b Connect charging hose from appropriate refrigerant cylinder vapor valve to compressor suction service valve c Open cylinder valve and add vapor charge Under the above conditions the system is properly charged when the condenser sight glass is clear with occasional bubbles showing Add or remove refrigerant until the proper charge is obtained d Backseat suction service valve Close vapor valve on refrigerant drum Replace all valve caps 4 8 CHECKING FOR NONCONDENSIBLES To check for noncondensibles proceed as follows a Stabilize system to equalize pressure between the suction and discharge side of the system The engine needs to be off for several hours b Measure temperature at any of the copper tubing in the condenser c Check pressure at the compressor discharge service valve d Determine saturation pressure as it corresponds to the condenser temperature using the Temperature Pressure Chart Table 4 6 If gauge reading is 3 psig 2 BAR or higher than the calculated P T pressure in step d noncondensibles are present f Remove refrigerant using a refrigerant recovery system Refer to paragraph 4 6 3 g Evacuate and dehydrate the system Refer to paragraph 4 6 h Charge the unit Refer to
50. arms are viewed this will be the number If no alarms are present the display will show first alarm to be shown To access the alarm codes press the UP and DOWN arrow keys at the same time and hold for 3 3 24 Alarm Clear seconds If multiple alarms are present the user can T scroll through each alarm by pressing the AUTO key When the end of the alarm list is reached the display will show Press VENT to scroll backward from the latest Se earliest 0505 using the ey to scroll back only the alarm code will be shown the alarm time will not be shown If the 3 3 TROUBLESHOOTING The user may clear inactive alarms using the Micromate control panel keypad Refer to paragraph 3 2 1 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 Table 3 3 3 1 329 Table 3 2 Alarm Codes ALARM TITLE CAUSE REMEDY CONTROLLER NO RESPONSE 11 Coil Freeze Coil temperature is less than 32 F and the compressor is op erating A12 Voltage The battery voltage is Check repair re greater than 32 volts alternator Low Voltage The battery voltage is less than 17 volts Return air tempera ture sensor failure or wiring defective Return Air Probe Failure Suction Pressure Transducer Failure Low Pressure Shutdown d
51. ature 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 equipped with unloader valves UV1 and UV2 each controlling two cylinders this allows the 05G to be operated 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 control it remains energized for two minutes to prevent short cycling Only one unloader may change state at a time when staging is required Operating 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 gr
52. ava kv d y uv HSJA 98 SEINS uaa _ v 10 98 00 21 8 vd2 lt lt V rd0 y 003 XH d sare E V 42 9 e Mii vr H 242 lt xxx 17 19 139 142 lt lt lt gt YOLWYOA VAT i g lt me LIEST gt ONO Hua ky e gt 8 2 LaS 3 v Ge 338 LZ lt lt gt gt 02 19 gt 8 61 338A 1 amp mz 91 gt a ka lt T 088344800 P C Y ast 4 9 gt y 01 1051 KY lt 6 051 JNN 200 ME gt a 9 330Q0R 31007 8353009 9 as D 90 89500 21 y Ko lt Bes zow xi bt z K AYASI lt 4 0 16c00 Zi 1 O0AZL ps d Figure 5 3 Electrical Schematic Diagram Sheet 2 of 2 Based On Drawing No 62 10981 Rev SEE FIG 5 4 24V MICROMATE CONTROL PANEL DISPLAY RELAY BOARD CLUTCH RELAY JUMPER LOGIC BOARD DRIVER LSV FAULT RELAY N EF HIGH EVAP MOTOR JUMPER OVERLOAD JA JUMPER li 5 5 9 L Es RE GRD PTB2 See Figure 5 1 for legend and symbols Figure 5 4 Wiring Schematic Logic Relay Board 12 00486 00 T 329 5 4 COND RELAY 2 CM20L A COND FAN REL
53. can also damage vehicles paint plastic parts engine drive belts and coolant hoses Beware of unannounced starting of the evaporator and condenser fans Do not remove the evaporator cover or condenser fan guards without disconnecting the vehicle battery cable Safety 1 T 329 Be sure power is turned off before working on motors controllers and electrical control switches Tag system controls and vehicle battery to prevent accidental energizing of the system Do not bypass any electrical safety devices e g bridging an overload or using any sort of jumper wires the system should be diagnosed and any necessary repairs performed by qualified service personnel When performing any arc welding on the vehicle disconnect the vehicle battery In case of electrical fire extinguish with CO never use water Disconnect vehicle battery power if possible SPECIFIC WARNINGS AND CAUTIONS WARNING Be sure to observe warnings listed the safety summary the front of this manual be fore performing maintenance on the HVAC system WARNING Do not use a nitrogen cylinder without a pressure regulator WARNING Do not use oxygen in or near a refrigeration system as an explosion may occur 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 compressor oil WARNING When moving the coil care
54. ctions 4 5 T 329 4 7 ADDING REFRIGERANT SYSTEM 4 7 1 Checking Refrigerant Charge a Connect an accurate high pressure gauge to the discharge service port at the compressor See Figure 4 4 b The condenser coil should be clean and free of any debris c Coach engine operating at high idle 800 1000RPM d The compressor should be fully loaded six cylinder operation e Unit must be operating in the cool mode until the discharge pressure has stabilized 3 to 5 minutes and the interior temperature is between 70 and 80 F 21 1 and 26 7 C f Discharge pressure at least 150 psig 10 21 BAR and stable for R 134a systems It may be necessary to partially block condenser airflow to raise discharge pressure 9 Observe the Liquid Line Sight Glass and use the following chart to determine the condition of the refrigerant charge Table 4 1 Checking Refrigerant Charge Sight Glass n Good Possible over charge Continue to step Liquid present Clear of all bubbles Liquid present Occasional bubbles present Liquid present Many bubbles present Good Possible under charge Continue to step i h If the conditions in steps b thru f are met and there is still doubt about the refrigerant charge level use Table 4 2 Table 4 2 Checking Refrigerant Charge Condenser Inlet Air Discharge Pressure Temperature Range 6 296 728 929 18 120 145 8 16 9 87 21 130 155 8 85 10 55 9 537123
55. ditioning compressor De energizing the clutch electric coil disengages the clutch and removes power from the compressor The clutch will be 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 pressure falls to the reset point of the high pressure switch The clutch coil will be de energized whenever the suction pressure decreases below 6 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 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 meter
56. e determined in step 8 from the temperature measured in this step The difference is the superheat of the suction gas Repeat steps 8 and 9 six times at three minute intervals and average the six readings to determine average superheat Average superheat should be 12 to 22 F 6 7 to 12 2 C 4 12 MODEL 05G COMPRESSOR MAINTENANCE 4 12 1 Shaft Seal Reservoir If compressor is fitted with a shaft seal reservoir it is recommended that the reservoir is serviced checked and drained at least once a year Refer to the 05G Twin Port workshop manual 62 11052 for complete instructions 4 12 2 Removing the Compressor If compressor is inoperative and the unit still has refrigerant pressure isolate the compressor and remove the refrigerant Refer to paragraph 4 4 3 If compressor is operative perform a pump down Refer to paragraph 4 4 4 a Turn main battery disconnect switch to OFF position and lock b Loosen the compressor drive belt and remove c Loosen bolts at suction and discharge service valve flanges and break seal to be sure pressure is released d Remove bolts from suction and discharge service valve flanges h Tag and disconnect wiring to the high pressure cutout switch discharge pressure transducer suction pressure transducer unloaders and the clutch Remove four bolts holding compressor to base Attach sling or other device to the compressor and remove compressor from the coach thro
57. e manifold gauge set can be used to determine system operating pressures add charge equalize or evacuate the system Low Pressure High Pressure Gauge Closed Frontseated Hand Valve Opened Backseated Hand Valve To Low Side Access Valve To High Side Access Valve 5 Red Knob Blue Knob Manifold Gauge Set Hose Fitting 0 5 16 Acme Refrigeration and or Evacuation Hose SAE J2196 R 134a Hose Fitting w O ring M14 x 1 5 High Side Field Service Coupler Low Side Field Service Coupler Figure 4 2 Manifold Gauge Set R 134a 4 3 1 An 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 CTD P N 07 00294 00 which includes items 1 through 6 see Figure 4 2 To perform service using the manifold gauge hose set do the following Installing R 134a Manifold Gauge Set 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 evacuated to remove contaminants and air as follows 2 Back seat turn counterclockwise both field service couplers See Figure 4 2 items 5 and 6 and midseat both hand valves 3 Connect the yellow hose to a vacuum pump and an R 134a cylinder T 329 4 2 4 Evacuate to 10 inches 0 69 BAR of vacuum and then charge with R 134a to a slightly
58. ean Replace Repair Replace Replace Repair Replace Repair Replace Clean Replace Clean Defrost Replace 4 11 ee Replace 4 11 Clean Check Replace Check Clean Open Repair Replace Repair Replace Check Replace Replace Repair Replace 1 7 Continuous Heating Reheat coolant solenoid valve stuck open 3 5 329 SECTION 4 SERVICE WARNING Be sure to observe warnings listed in the safety summary in the front of this manual before performing maintenance on the HVAC system NOTE Following completion of all maintenance or service activities the alarm queue should be cleared of any original alarms and any alarms generated during service Refer to paragraph 3 2 1 4 1 MAINTENANCE SCHEDULE MEUM REFERENCE OPERATION paragraph a Maintenance X Pre trip Inspection after starting X Check tension and condition of V belt b Weekly Inspection Perform daily inspection Check condenser evaporator coils and air filters for cleanliness 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 Clean evaporator drain pans and hoses Check wire harnesses for chafing and loose terminals Replace Tighten Check fan motor bearings None Check compressor mounting bolts for tightness None Check fan motor brushes 4 18 4 22 4 2 SUCTION AND
59. eases above 330 PSIG and UV1 has been energized for 30 seconds unloader UV2 is then energized this unloader will remain en ergized for 1 minute then be allowed to de energize when the pressure decreases below 245PSIG 2 3 6 Evaporator Fan Speed Selection Temperature control is the primary method of determining the fan speed selection Section NO TAG or section 2 3 7 1 describe relay operational status for the evaporator fans while Figure 2 1 provides Logic Board speed selections at various deviations from set point 2 3 7 Fan Motor Operation Sequence The evaporator and condenser fans are energized by relays on the relay board Depending on relay board configuration the fan ON and fan HIGH SPEED relays may be directly energized by the microprocessor or they may be energized by a set of interim relays 2 3 7 1 Relay Board 12 00486 01 On systems with relay board 12 00486 01 see Figure 1 9 Power is available from relay board terminal JC 1 see Figure 1 9 to the fan ON relays K1 amp K7 and fan HIGH SPEED relays K2 amp K8 and grounded thru terminals JC 2 3 4 5 When condenser operation is required the microprocessor energizes grounds thru JC 5 the condenser fan ON relay K7 Relay K7 closes it s contacts to energize the condenser fan relays CFR1 and CFR2 With the CFR relay contacts closed power flows from the circuit breaker through the relay contacts to the condenser fan motors When high speed co
60. eater than 3 F 1 7 C above set point UV 1 will be de energized to place the compressor at 10096 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 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 remain 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 and stays above 330 PSIG for 3 seconds unloader UV1 is energized this unloader will remain energized until the pressure de creases below 265 PSIG for a minimum of one min ute UV2 needs to be de energized for at least 30 seconds for before UV1 will de energize 2 Compressor Unloader UV2 Relay When the dis charge pressure incr
61. efective Discharge Pressure Transducer Failure T 329 Suction pressure transducer failure or wiring defective Discharge pressure transducer failure or wiring defective Low suction pressure Switch open or wiring Check causes of coil freezing Refer to section 3 3 6 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 13 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 3 An alarm will be gener ated and the system will shutdown The evapora tor fans will remain run ning while the compres sor 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 fan
62. egrees with the up and down keys to a value between 60 F and 80 F P19 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 2 5 329 Table 2 2 Parameter Codes Continued Code P20 Compressor Hours This is the number of hours of operation that the compressor has run with the High 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 High fans energized 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 P20 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 1 Hour This is the value of compressor hours low P21 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 2 Hours This is the value of evaporator fan hours high P2
63. emperatures falls below Logic Board set point The system will operate in these modes unless pressures override the Logic Board settings 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 Cooling 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 will operate in the reheat mode A controller programmed for reheat will maintain compressor operation and cycle the heat valve to allow reheating of the return air Interior temperature is maintained at the desired set point while additional dehumidification takes place T 329 2 2 2 3 3 Heating 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 air over the evaporator coil based on the temperature difference from setpoint 2 3 4 Vent Mode In the vent mode the evaporator fans are operated to circulate air in the bus interior 2 3 5 Compressor Unloader Control When operating in cooling the unloaders are used to reduce system capacity as return air temper
64. fifth control is the Micromate Control Panel Figure 1 10 which communicates with the Carrier Transicold Micromax microprocessor controller which consists of a logic board fuses and relays Modes of operation include Vent and Auto 1 2 6 Other Carrier Supplied Items Other Carrier supplied items include two return air temperature sensors two coolant control valves and a check valve The temperature sensors provide input to the controller on temperature conditions in the coach The bypass heat coolant control valve provides a path for coolant flow when all evaporator heat valves are closed The other coolant control valve is the heat valve that controls the flow of coolant to the driver heater coil The check valve is installed in the refrigerant discharge line at the condenser and allows refrigerant flow in only one direction to prevent liquid return to the compressor when the compressor is shut down T 329 1 3 REFRIGERATION SYSTEM COMPONENT SPECIFICATIONS a Refrigerant Charge R 134a 17 5 lb 8 kg b Compressor Model 05G No of Cylinder 6 Weight Dry 145 Ib 66 kg including clutch Oil Charge New Compressor 5 8 pints 2 7 liters Replacement Compressor 5 5 pints 2 6 liters Oil Level Level in sight glass between bottom of glass and middle of glass on compressor crankcase curbside Approved Compressor Oils R 134a Castrol SW68C Mobil EAL Arctic 68 ICl Emkarate RL68H c Thermostatic Expans
65. g Pressing the Micromate ON OFF button will stop system operation 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 12 5 c Check refrigerant charge Refer to section 4 7 1 d Ensure that self test has been successfully per formed and that there are no errors or alarms indi cated Refer to section 2 1 3 T 329 2 3 MODES OF OPERATION The system is operated by a Carrier Transicold Micromax microprocessor controller which consists of a logic board Figure 1 8 relay board Figure 1 9 and manual operator switches The logic board regulates operational cycles modes of the system by energizing or de energizing Relay Board relays in response to deviations in interior temperature Modes of operation include Cooling Heat and Vent Refer to Figure 2 1 and 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 Auto 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 t
66. he coach the third sensor is located in the condenser section The two inside sensors are wired in parallel and together send an averaged signal to the controller If one of these sensors fails the control function will continue with the remaining sensor The sensor located in the condenser section reads outdoor temperature i E S 20 E E 00557 2 30 32 e 50 60 80 90 100 ES alo P ie 4 14 SUCTION AND DISCHARGE PRESSURE TRANSDUCER CHECKOUT NOTE 1 System must be operating to check transducers T 329 2 Both transducers are mounted the compressor a With the system running use the driver display or manifold gauges to check suction and or discharge pressure s b Use a digital volt ohmmeter to measure voltage across the transducer and compare to values in Table 4 4 A reading within two percent of the values in the table would be considered good Transducer SPT and DPT Voltage Psig Voltage Psig Voltage sig Voltage 0 0466 115 1593 230 2720 60 1054 175 2481 290 3 308 80 1250 195 2377 310 3504 90 1348 205 2475 320 3602 4 15 REPLACING SENSORS AND TRANSDUCERS a Turn main battery disconnect switch to OFF position and lock b Tag and disconnect wiring from defective sensor or transducer c Remove and replace defective sensor or transducer d Connect wiring to replacement sensor
67. he evaporator to obtain maximum use of the evaporator heat transfer surface The low pressure low temperature liquid that flows into the evaporator tubes is colder than the air that is circulated over the evaporator tubes by the evaporator blower fan 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 coach 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 When ventilation only is selected by the main controller only the evaporator fans function to circulate air throughout the coach The refrigerant cycle will remain off T 329 DRIVER SOLENOID VALVE m Discharge gt mmm Liquid cma Suction TXV BULB DRIVER EVAPORATOR SERVICE PORT ASSEMBLY TXV BULB Ra Pa TA PA T Pa RA PA TAPA TPA MAIN EVAPORATOR ASSEMBLY SERVICE
68. he 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 2 The Micromate Control Panel Display see Figure 1 10 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 is programmed to display set point temperature 3 If ventilation only is desired press the Vent button Figure 1 10 to illuminate the indicator light and place the system in that mode of operation 4 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 5 To open or close the fresh air damper press the FRESH AIR button to illuminate the indicator light and bring the damper to the desired position 2 1 6 To read interior or exterior temperature press the TEMPERATURE button to illuminate the
69. indicator light and bring the display to the desired temperature reading After a 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 8 The Auto button places the system into the Auto mode where the system is energized to provide cool ing or heating as required to control the interior tem perature to the desired set point 9 For additional Micromate operating data refer to 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 alarm will be indicated by flashing 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 or on the Micromate display Refer to section 3 for definition of system errors and alarms and general troubleshooting procedures 2 1 4 Stoppin
70. ion Valve for R 134a Units 1 Main Evaporator Superheat Setting Nonadjustable 12 to 22 F 6 7 to 12 2 MOP Setting None 2 Driver Evaporator and Parcel Rack Evaporator Superheat Setting Nonadjustable 5 to 12 F 6 7 to 12 2 MOP Setting None d High Pressure Switch HPS Opens at 385 10 psig 26 2 68 BAR Closes at 285 10 psig 19 39 68 BAR 1 4 ELECTRICAL SPECIFICATIONS WOUND FIELD MOTORS a Main Evaporator Heater Blower Fan Motor Bearing Lubrication Factory Lubricated additional grease not required Horsepower High Speed 1 6 7 2 kw Low Speed 0 7 0 5 kw Full Load Amps FLA High Speed 56 Low Speed 28 Operating Speed High Speed 1550 Low Speed 1200 rpm Voltage 24 T 329 b Driver Evaporator Heater Blower Fan Motor Bearing Lubrication Factory Lubricated additional grease not required Full Load Amps FLA 9 5 Operating Speed High Speed 3300 rpm Medium Speed 1600 rpm Low Speed 1100 rpm Voltage 24 vdc c Condenser Fan Motor Bearing Lubrication Shell Dolium R Horsepower 0 8 hp 1 072 kw Full Load Amps FLA High Speed 32 Low Speed 21 Operating Speed High Speed 1800 rpm Low Speed 1600 rpm Voltage 24 vdc d Parcel Rack Evaporator Fan Motor Bearing Lubrication Factory Lubricated additional grease not required Full Load Amps FLA 9 5 Operating Speed 3300 rpm Voltage 24 vdc 1 5 ELECTRICAL SPECIFIC
71. lamp Nut and Bolt clamp Thermocouple TXV Bulb Shown in the four o clock position Figure 4 7 Thermostatic Expansion Valve Bulb and Thermocouple Installation 4 11 2 To Check Measure Superheat T 329 NOTE All readings must be taken from the leaving side of the evaporator a Open the evaporator compartment door in the third baggage bay Open filter access door c Remove Presstite insulation from expansion valve bulb and suction line d Loosen one TXV bulb clamp and make sure area under clamp above TXV bulb is clean e Place temperature thermocouple in contact with the suction tube and parallel to the TXV bulb and then secure loosened clamp making sure both bulbs are firmly secured to suction line See Figure 4 7 Reinstall insulation around the bulb f Connect an accurate low pressure gauge or install a manifold gauge set to the service port on the leaving side of the evaporator Refer to paragraph 4 3 9 Close evaporator access door being careful to route thermocouple sensing wire and guage hose thru the access hole to outside the evaporator Start coach and run on fast idle until unit has stabilized about 20 to 30 minutes i From the temperature pressure chart determine the saturation temperature corresponding to the evaporator outlet pressure Refer to Table 4 6 o 2 j Note the temperature of the suction gas at the expansion valve bulb Subtract the saturation temperatur
72. line drawn in step d b x Re secure the motor with the four bolts removed in step g Check fan rotation insuring that the fan wheels do not make contact with the fan housings Complete the procedure by performing steps a thru in reverse 4 18 SERVICING MOTOR BRUSHES If the brushes are broken cracked severely chipped or worn to 1 3 their original length replace them a Remove the four brush access doors on the motor b With fingers or a suitable hook lift the brush spring end up so the brush may slide up and out of the holder Loosen the brush screw to remove the brush shunt terminal Remove the brush To replace lift the brush spring and place the brush in the nee Position the end of the spring on top of the brush Connect the brush shunt terminal to its proper crossover with the brush screw assembled loosely Assure positioning of the brush to permit the brush shunt to travel freely in the holder slot as the brush wears If the brush hangs up commutator damage and motor failure will result e Tighten screw 4 19 SERVICING THE MAIN EVAPORATOR AND HEATER COIL a Drain engine coolant from the heater coil b Pump down low side of the HVAC system Refer to paragraph 4 4 1 c Remove remaining refrigerant Refer to paragraph 4 4 d Remove the evaporator motor by following paragraph 4 16 steps a thru f e Disconnect all remaining electrical connections move wires
73. must be taken to avoid personal injury because of the weight of the coil 4 CAUTION Do not under any circumstances attempt to service the microprocessor Should a problem develop with the microprocessor replace it yr Werne To prevent trapping liquid refrigerant in the manifold gauge set be sure set is brought to suction pressure before disconnecting CAUTION Care must be taken to ensure that the manifold common connection remains immersed oil at all times or air and moisture will be drawn into the system T 329 Safety 2 TABLE OF CONTENTS Section Page SAFETY SUMMARY 5 EET i GENERAL SAFETY NOTICES i FIRSTAID elut eee a a aA ME Wo e PA i OPERATING PREGAUTIONS iere E A 4 i MAINTENANCE PRECAUTIONS i SPECIFIC WARNINGS AND CAUTIONS i DESCRIPTION Ed a ian 1 1 INTRODUCTION 5 RU A e ERR REA 1 1 12 GENERALE DESGCRIPTION ntes baec dye 1 2 121 Condenser Assembly eoru n ebd teeters set eons 1 2 1 2 2 Compressor Assembly 1 4 1 2 3 Evaporator Assemblies 1 4 1 2 4 Main
74. nce Alarm 2 The evaporator hour Reset the 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 eno oh to energize suction pressure Re fer to section 3 3 3 High Pressure Warning Discharge pressure Check cause of high Alarm will be generated high enough to discharge pressure energize UV2 ed to section 3 3 3 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 3 3 329 Table 3 3 General System Troubleshooting Procedures INDICATION REFERENCE 3 3 1 System Will Not Cool Compressor will not run Active system alarm V Belt loose or defective Clutch coil defective Check Replace Clutch malfunction Check Replace Compressor malfunction See Table 1 2 Electrical malfunction Coach power source defective Check Repair Circuit Breaker safety device open Check Reset 3 3 2 System Runs But Has Insufficient Cooling Compressor V Belt loose or defective Check Compressor valves defective See Table 1 2 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 Check Restricted air flow No ev
75. ndenser fan operation is required the microprocessor energizes grounds thru JC 4 the HIGH SPEED relay K8 Relay K8 closes it s contacts to energize the condenser speed relay CSR With the CSR relay contacts closed power flows through the motor high speed circuit by passing the CSR resistor When evaporator fan operation is required the microprocessor energizes grounds thru JC 3 the relay K1 Relay K1 closes it s contacts to energize evaporator fan relay EFRL A circuit is established from the circuit breaker to the motor When high speed evaporator fan operation is required the microprocessor energizes grounds thru JC 2 the evaporator fan HIGH SPEED relay K2 Relay K2 closes its contacts to energize the evaporator speed relay ESRH which closes its contacts The circuit continues through the motor high speed circuit S2 to S3 adding an additional ground circuit 2 3 8 Condenser Fan Control The condenser fans energized when the compressor clutch output is energized The fans are started in low speed and will remain in low speed until the discharge pressure increases to 190 psig The fans will remain in high speed until discharge pressure decreases below 135 psig The fans will also be activated if a high pressure alarm has been activated and operation has not been locked out refer to Table 3 2 T 329 2 3 9 Compressor Clutch Control A belt driven electric clutch is employed to transmit engine power to the air con
76. ning the condenser to the coach h Remove the stabilizing bracket on the top of the condenser i Remove the eight screws securing the condenser door hinges to the frame j Remove condenser module by sliding out on mounting rails 4 21 SERVICING THE CONDENSER COIL a Remove the condenser assembly from the coach Refer to paragraph 4 20 b Remove side panel with control box c Remove front shroud and panel assemblies d Unbraze coil tubing connections and roll front module assembly forward to provide clearance for coil removal e Remove condenser coil f Repair or replace the condenser coil g Re install by performing the above procedure in reverse 4 22 SERVICING THE CONDENSER MOTOR a Turn main battery disconnect switch to OFF position and lock b Remove appropriate front condenser grill c Remove fan blade secure the shaft key to the motor shaft or fan hub slot d Disconnect the wires to the motor e Remove the four motor base mounting screws f Remove the motor and place on workbench g Repair or replace defective component s as required h For brush inspection replacement refer to paragraph 4 18 i Re install by performing the above procedure in reverse 4 23 SERVICING THE DRIVER CONTROL BOX The driver control box is located behind the return air panel below the passenger side dash and under the right headlight See Figure 4 10 Remove the return air panel by removing the
77. on an ohmmeter no continuity f Close cylinder valve and release pressure through the bleed off valve As pressure drops to cut in point the switch contacts should close indicating continuity on the ohmmeter 4 10 FILTER DRIER 4 10 1 To Check Filter Drier Check for a restricted or plugged filter drier by feeling the liquid line inlet and outlet connections of the filter drier If the outlet side feels cooler than the inlet side then the filter drier should be changed 4 10 2 To Replace Filter Drier a Pump down the unit Refer to paragraph 4 4 b Replace filter drier ensuring that the arrow points in the direction of the refrigerant flow c Drier can be evacuated at liquid line service valve See Figure 4 4 d Check refrigerant charge Refer to paragraph 4 7 1 Power Head Assembly Equalizer Connection Bulb Cage Assembly Seat Gasket Body Flange Capscrew Body Flange Gasket Figure 4 6 Thermostatic Expansion Valve 4 11 THERMOSTATIC EXPANSION VALVE The thermostatic expansion valve TXV is automatic device which maintains constant superheat of the refrigerant gas leaving the evaporator regardless of suction pressure The valve functions are a automatic response of refrigerant flow to match the evaporator load and b prevention of liquid refrigerant returning to the compressor Unless the valve is defective it seldom requires any maintenance All TXV s are non adjustable
78. or Heater Coil Assembly 4 14 4 24 5 RAM Air Actuator Removal 4 14 4 25 SERVICING THE PARCEL RACK EVAPORATOR 4 14 4 25 1 Motor Removal eich etek ro EE Verb eu VE iv eiu 4 14 4 25 2 Removal of Parcel Rack Evaporator Coil 4 14 4 26 LOGIC BOARD REPLACEMENT 4 15 ELECTRICAL SCHEMATIC 5 1 5 1 INTRODUCTION 2 AR EE RUE Dm REED ERE EMERGERE ce ee as 5 1 329 LIST OF ILLUSTRATIONS Figure Page 1 1 Coach Cutaway View 2 1 1 1 2 Condenser Assembly 1 1 2 1 3 Compressor Assembly 1 3 1 4 Driver Gorntrol Ole det eas ead ed eae C ae ga 1 4 1 5 Driver Evaporator Assembly 2 1 5 1 6 Parcel Rack Evaporator Assembly 1 5 1 7 Main Evaporator Assembly 2 1 6 1 8 Logic Board 1 7 1 9 Relay Board
79. or transducer e Checkout replacement sensor or transducer Refer to paragraph 4 13 or 4 14 as applicable T 329 4 12 4 16 SERVICING MAIN EVAPORATOR BLOWER ASSEMBLY a Turn main battery disconnect switch to OFF position and lock Remove access door located in the baggage compartment To remove the access door grab recessed handles and pull up Disconnect electrical connections to the motor d Remove blower transitions ducts Remove the four bolts securing the evaporator motor mounting plate motor and blower housing assembly to the bottom panel Remove motor and blower wheel assembly by sliding out of evaporator housing Repair or replace any defective component s as required Replace by reversing steps b thru f 4 17 ACCESSING MAIN EVAPORATOR MOTOR BRUSHES Turn main battery disconnect switch to OFF position and lock Remove access door Refer to 4 16 b c Disconnect electrical connections to the motor With a marker trace the outline of the motor on the motor plate Remove the four brush access doors on the motor Service two brushes top front and top rear Remove the four bolts securing the evaporator motor to the mounting plate Rotate the motor to gain access to the lower front brush Rotate the motor the opposite way to gain access to the lower rear brush j Rotate the motor back to its feet and position back to its original position guided by the out
80. orator liquid line solenoid valve and the parcel rack liquid line solenoid valve when so equipped closes when the system is shut down to prevent refrigerant migration and to isolate the filter drier for servicing when the compressor is shut down The king valves enable servicing of the condenser assembly The ambient temperature sensor measures ambient temperature and sends an electrical signal to the main controller m 1 h Condenser Coil Assembly Fusible Plug Liquid Line Outlet Fitting Parcel Rack Liquid Line Outlet Fitting Main Model Serial No Nameplate Fan Guard Filter Drier Venturi Ring Condenser Fan Motor CM1 Fan Blade Condenser Fan Motor CM2 Outside Temperature Sensor Negative Stud Moisture amp Liquid Indicator Positive Stud Positive Stud Liquid Line King Valve Discharge Shutoff King Valve Refrigerant Inlet Fitting Discharge Check Valve Figure 1 2 Condenser Assembly T 329 UI CUI UI uD mu UJ ur ur ur DRIVE END VIEW PUMP END VIEW
81. outside of the condenser tubes Heat transfer is established from the refrigerant inside the tubes to the condenser air flowing over the tubes The condenser tubes 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 The refrigerant leaves the condenser and then flows through the subcooler which subcools the refrigerant before it enters the thermal expansion valves this reduces flash gas in the evaporator From the subcooler the liquid refrigerant passes through the liquid line King service valve and then through a filter drier where an absorbent keeps the refrigerant clean and free of water From the filter drier the liquid refrigerant then flows through the main liquid line solenoid valve to the main evaporator and thermal expansion valve and to the 1 13 parcel rack evaporator solenoid valve if this option is active the parcel rack thermal expansion valve and through the driver solenoid valve if this option is active and to the driver thermal expansion valve The solenoid valves open during cooling to allow refrigerant to flow to the thermal expansion valves The main liquid solenoid valve and the parcel rack liquid line solenoid valve when so equipped closes during shutdown to prevent refrigerant migration The thermal expansion valves reduce the pressure and temperature of the liquid and meters the flow of liquid refrigerant to t
82. paragraph 4 6 Charge the unit Refer to paragraph 4 7 Ensure that self test has been performed and that there are no errors or alarms indicated Refer to paragraphs 2 1 3 and 2 4 2 4 6 EVACUATION AND DEHYDRATION 4 6 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 4 6 2 Preparation 2 NOTE 1 Using a compound gauge for determination of vacuum level is not recommended because of its inherent inaccuracy Never evacuate an open drive compressor below 500 microns T 329 a Evacuate and dehydrate only after pressure leak test Refer to paragraph 4 5 b Essential tools to properly evacuate and dehydrate any system include a good vacuum pump with a minimum of 6 cfm 10 2 mS hr volume displacement CTD P N 07 00176 11 and a good digital micron vacuum indicator CTD P N 07 00414 00 Keep the ambient temperature above 60 F 15 6 to speed evaporation of moisture If ambient temperature is lower than 60 F 15 6 ice may form before moisture removal is complete It may be necessary to use heater blankets heat lamps or alternate sources of heat to raise system temperature 4 6 3 Procedure for Evacuation and Dehydrating System a Remove refrigerant using a refrigerant recove
83. r and pumps 2 1 2 ounces 72 5 milliliters per stroke when connected to the suction service valve port Also there is no need to remove pump from can after each use When the compressor is in operation the pump check valve prevents the loss of refrigerant while allowing servicemen to develop sufficient pressure to overcome the operating suction pressure to add oil as necessary Backseat suction service valve and connect oil charging hose to port Crack open the service valve and remove air from the oil hose at the oil pump Add oil as necessary NOTE Allow time at least 60 seconds for the oil to flow thru to the crankcase and show on the sightglass 12 6 2 Closed System Method Install manifold gauge set See Figure 4 3 Unplug the suction pressure transducer SPT Frontseat the compressor suction service valve by turning clockwise Start the unit and run in cooling until 10 hg 25 4 cm hg of vacuum is reached Shut the system down and tag out system power source Frontseat the compressor discharge service valve and wait 5 minutes to verify vacuum is maintained Remove the crankcase oil fill plug on the side of the crankcase Replace the crankcase oil fill plug with a Carrier Service Parts no 889 fitting This fitting has a 1 4 inch flare access port with a shrader valve Using refrigerant hoses designed for vacuum service connect a vacuum pump to center connection of manifold gauge
84. r assembly includes an evaporator and heater coil assembly a thermal expansion valve an evaporator heat valve EHV a fan and motor assembly and two condensate drain holes There is also an evaporator control panel assembly which controls the main evaporator fans and condenser fans upon receipt of a signal from the main controller The optional parcel rack evaporator assemblies includes an evaporator coil assembly a thermal expansion valve a fan and motor assembly condensate drain connection and return air thermostat on the road side only The evaporator coils provide a heat transfer surface for transferring heat from air circulating over the outside surface of the coil to refrigerant circulating inside the tubes thus providing cooling when required The thermal expansion valves meter the flow of refrigerant entering the evaporator coils The heating coils provide a heat transfer surface for transferring heat from engine coolant circulating inside the tubes to air circulating over the outside surface of the tubes thus providing heating when required The evaporator heat valve s EHV controls the flow of engine coolant supplied to the heating coils The fans circulate the air over the coils The air filters filter dirt particles from the air before the air passes over the coils The condensate drain connections provide a means for disposing of condensate collected on the evaporator coils during cooling operation 14 13
85. ry system CTD P N MVS 115 F L CT for 115 volt power source or CTD P N MVS 240 F L CT for 240 volt power source The recommended method is connecting two lines 3 8 OD copper tubing or refrigerant hoses designed for vacuum service to the manifold guage set Attach one line to the condenser service King valve and the other line to the evaporator service port See Figure 4 4 c Connect lines to unit and manifold and make sure vacuum gauge valve is closed and vacuum pump valve is open To speed up evacuation time open solenoid valves electrically additional vacuum pump be added and connected to the compressor suction service port See Figure 4 4 Start vacuum pump Slowly open valves halfway and then open vacuum gauge valve f Evacuate unit until vacuum gauge indicates 1500 microns vacuum Close gauge valve vacuum pump valve and stop vacuum pump Break the vacuum with clean dry refrigerant or dry nitrogen Use the refrigerant that the unit calls for BAR system pressure to approximately 2 psig 0 14 h Remove refrigerant using a refrigerant recovery system or if using nitrogen vent to atmosphere i Start vacuum pump and open all valves Evacuate unit to 500 microns vacuum j Close off pump valve isolate vacuum gauge in system and stop pump Wait five minutes to see if vacuum holds k With a vacuum still in the unit the refrigerant charge may be drawn into the system from a refriger
86. s and heat and the system is locked out until the pow er is cycled or the alarm is reset Table 3 2 Alarm Codes Continued ALARM TITLE CAUSE REMEDY CONTROLLER NO RESPONSE High Discharge Pressure High 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 3 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 Breaker Trip Blown Fuse breaker fuse on the Check breakers fuse Alarm will be generated relay board has for tripped device Re tripped or relay pair short and reset has failed replace breaker fuse Evaporator Fan Overload TE RA fan over 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 Need ECL Neue Maintenance Alarm 1 The compressor hour Reset the mainte Alarm will be generated meter is greater than nance hour meter the value in Mainte nance Hour Meter 1 Maintena
87. s 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 NOTE If a replacement Logic Module is installed it is necessary to match the configuration jumpers See Figure 1 8 to the original board Refer to paragraph 4 26 2 4 4 Control a Activate the system by pressing the I O key on the Mi cromate panel 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 T 329 2 4 parameters to be viewed If there 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 2 While in the diagnostic mode press an UP or DOWN arrow key to switch the display to the Parameter Display With the first Parameter
88. s the rear for removal 4 26 LOGIC BOARD REPLACEMENT Control configuration is preset at the factory 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 8 to the original board Table 4 5 provides a list of jumper functions Carrier is not responsible for failures or damage resulting from unauthorized changes Table 4 5 Logic Board Configuration Configuration A High Reheat When this configuration is removed the unit will default to high speed in reheat mode and in the low speed cool band If not removed heat reheat will default 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 Dry Heat When this configuration is removed the unit will run on 10096 reheat instead of heat 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 Refrigerant R 22 R 134a When the refrigerant configuration is removed the refrigerant is set for R 22 The default refrigerant is R 134a With G removed and H removed 385 PSIG high pressure switch With removed and installed 300 PSIG high pressure switch Factory
89. set CAUTION Care must be taken to ensure that the manifold common connection remains immersed in oil at all times or air and moisture will be drawn into the system i Connect a refrigerant hose with a shrader depressor to the fitting described in step g above put the other end of the hose in a fresh oil container j Evacuate the compressor and observe the oil level in the compressor crankcase When the desired oil level is reached disconnect the hose from the fitting k Reinstall the crankcase oil fill plug Using refrigerant hoses designed for vacuum service connect a vacuum pump to center connection of manifold gauge set Evacuate system to 500 microns Close off pump valve isolate vacuum gauge and stop pump Wait 5 minutes to verify that vacuum holds m Once vacuum is maintained backseat compressor service valves and disconnect manifold gauge set n Reconnect the suction pressure transducer SPT 4 12 7 Adding Oil to Service Replacement Compressor Service replacement compressors may or may not be shipped with oil If the replacement compressor is shipped without oil add oil through the oil fill plug See Figure 4 9 4 12 8 Removing Oil from the Compressor a If the lowest oil level observed in paragraph 4 12 5 step c is above middle of the sight glass on compressor crankcase oil must be removed from the compressor by performing the following procedure If lowest oil level visible is below bo
90. slide right hand side air filter towards center and turn right corner past edge b Slide left hand side filter to the right and repeat as above c Clean replace filter and re install T 329 4 24 4 Removal of Evaporator Heater Coil Assembly a Clamp off silicon hose close to the input and output end of the heater core b Disconnect hose clamps and separate hose from fitting c Pump down the refrigerant system paragraph 4 4 1 Refer to d Disconnect liquid line solenoid valve plug e Disconnect expansion valve thermal bulb attached to the 7 8 inch copper tube f Disconnect 7 8 and 3 8 inch copper lines g Remove screws that attach the heater core to the unit h Lift evaporator coil up and pull towards the rear for removal 4 24 5 RAM Air Actuator Removal a Disconnect the plug b Remove the no 10 screw from the end of the spring on the RAM air actuator 4 25 SERVICING THE PARCEL RACK EVAPORATOR 4 25 1 Motor Removal a Disconnect the motor wires from the connector b Remove the two bolts from the motor mount and remove the motor c Remove the blower and motor assembly 4 25 2 Removal of Parcel Rack Evaporator Coil a Pump down the refrigerant system paragraph 4 4 1 Refer to b Remove the side access panel c Disconnect expansion valve thermal bulb attached to the 7 8 inch copper tube d Disconnect 7 8 and 3 8 inch copper lines e Lift evaporator coil up and push toward
91. t 5 minutes to verify that vacuum holds h Once vacuum is maintained backseat compressor service valves and disconnect manifold gauge set i Reconnect the suction pressure transducer SPT j the low pressure alarm Refer to paragraph 3 2 1 d T 329 4 5 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 It must be emphasized that only the correct refrigerant drum should be connected to pressurize the system Any other gas or vapor will contaminate the system which will require additional evacuation Ensure all the service valves and solenoid valves are open It will be necessary to energize the solenoid valves from an external power source Ifthe system is without refrigerant charge the system with refrigerant vapor to build up pressure between 30 to 50 psig 2 74 to 3 40 BAR c Add sufficient nitrogen to raise system pressure to a maximum of 150 psig 10 21 BAR Check for leaks It is recommended that an electronic leak detector be used to find refrigerant leaks in a system Testing joints with soapsuds is satisfactory and may be necessary under conditions when an electronic leak detector will not function correctly Remove refrigerant from system and repair any leaks f Evacuate and dehydrate the system Refer to
92. ters can release pressurized refrigerant Slowly release pressure and always wear appropriate safety wear Avoid breathing any refrigerant vapor lubricant vapor or mist Exposure to these particularly PAG oil mist may irritate your eyes nose or throat Always use a DOT Department of Transportation approved cylinder for storing used and recycled refrigerant Approved cylinders will be stamped DOT 4BW or DOT 4BA Carrier recommends a MACS Mobile Air Conditioning Society certification in Recovery Recycling to gain more information on handling and using refrigerants Never attempt to apply heat or open flame to a refrigerant cylinder High temperatures can raise the cylinder pressure to dangerous levels Carrier recommends using a heat blanket to increase the internal temperature of the refrigerant cylinder greatly increasing the transfer of refrigerant to the bus air conditioning system Never use compressed air shop air to leak test or pressure test a R134a system Under certain conditions pressurized mixtures of R134a and air can be combustible In addition shop air will inject moisture into the system Always use mineral oil to lubricate Rings hoses and fittings on R134a systems PAG oils will absorb moisture and become very acidic and corrosive Mineral oil will not absorb moisture and thus prevent corrosion Always wear gloves when working with PAG and Ester lubricants to prevent irritation to your skin R134a lubricants
93. to low This value can be modified between 0 and 10 degrees F The default value is 1 degree F 3 P12 Heat Control Window This is the number of degrees below setpoint before the reheat coolantvalve is energized This value can be modified between 0 and 10 degrees F default value is 2 degree F for heat and 4 degrees F for reheat P13 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 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 High This is the current state of the compressor high pressure switch input CL will Pressure Switch be displayed if it is closed and will be displayed if it is open P17 Condenser Fan Not used Speed Switch P18 Maximum Setpoint This is the maximum value that the operator will be allowed to set the setpoint temperature The value can be modified in d
94. ttom of the sightglass oil must be added to the compressor by following the procedure in paragraph 4 12 6 b Close frontseat suction service valve and pump unit down to 3 to 5 psig 21 to 34 kPa Reclaim remaining refrigerant NOTE If oil drain plug is not accessible it will be necessary to extract oil through the oil fill plug with a siphon tube 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 compressor oil c Remove the oil drain plug on the bottom plate of the compressor and drain the proper amount of oil from the compressor Replace the plug securely back into the compressor d Repeat step a to ensure proper oil level 4 13 TEMPERATURE SENSOR CHECKOUT An accurate ohmmeter must be used to check resistance values shown in Table 4 3 b Due to variations and inaccuracies in ohmmeters thermometers or other test equipment a reading within two percent of the chart value would be considered good If a sensor is bad the resistance value would usually be much higher or lower than the value given in the Table 4 3 Table 4 3 Temperature Sensor AT TSC TSD and TSR Resistance Tem P Resistance In Ohms E 7233 EIE 122 00 156 55 57 322 0 374 233 489 NOTE This system is equipped with three temperature sensors two located in the return air ducts inside t
95. ugh the right rear access door Set the compressor on a sturdy work surface 4 12 3 Re installing the Compressor NOTES 1 The service replacement 05G compressors are sold without shutoff valves Valve pads are installed in their place The optional unloaders are not supplied as the cylinder heads are shipped with plugs The customer should retain the original unloader valves for use on the replacement compressor 2 The piston plug that is removed from the replacement compressor head must be installed in the failed compressor if returning for warranty 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 3 and 4 12 5 5 Service replacement compressors are supplied with a suction filter sock for initial startup Ensure the filter sock is installed and removed in accordance with the instructions furnished a Remove the three socket head capscrews from both unloader valves on the side heads of the 05G compressor Remove the unloader valve and bypass piston assembly keeping the same capscrews with the assembly See Figure 4 8 The original unloader valve must be transferred to the replacement compressor The plug 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
96. ure 1 6 Parcel Rack Evaporator Assembly 1 5 T 329 1 2 3 4 5 6 7 8 9 329 16 15 13 14 12 Thermal Expansion Valve Refrigerant Liquid Inlet Connection 3 8 ORS Evaporator Heater Coil Assembly Heater Coil Inlet Connection 7 8 OD Evaporator Heat Valve EHV Blower Housing Right Blower Wheel Right Nameplate Condenser Fan Relay 2 CFR2 Condenser Fan Relay 1 CFR1 Condenser Fan Speed Relay CSR Evaporator Fan Relay Low Speed EFRL Evaporator Fan Relay High Speed EFRH Elastomeric Motor Mounts 2 Speed Motor Blower Wheel Left Blower Housing Left Service Port Coolant Drain valve Heater Coil Outlet Connection 7 8 OD Capillary Tube and Bulb TXV Refrigerant Suction Outlet Connection 1 ORS Air Bleed Valve Air Filter Channel Figure 1 7 Main Evaporator Assembly 11 10 9 8 1 6
97. vaporator and condenser fans Do not open the condenser fan grille or evaporator access panels before turning the power off and securing the power source Be sure power is turned off before working on motors controllers solenoid valves and electrical control switches Tag circuit breaker and power supply to prevent accidental energizing of circuit Do not bypass any electrical safety devices e g bridging an overload or using any sort of 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 static safe wrist strap In case of electrical fire open circuit switch and extinguish with CO never use water Familiarize yourself with the proper operation of any service equipment you will be using voltmeter amp probe manifold gauges etc Always read the owner s manual that is enclosed with the equipment Always follow the manufacturers instructions for your recovery recycling equipment Failure to do so could cause personal injury or damage to your equipment Never perform any maintenance or service on your equipment before consulting with authorized service personnel Always unplug unit before attempting any maintenance Removing internal fittings and fil
98. way Return Air END Wii Temperature Sensor Lah Check Valve Ambient Air Temperature Sensor Sw Bypass INDICATES COMPONENTS FURNISHED Heat BY THE COACH MANUFACTURER Valve Condenser Roadside Return Air Temperature Sensor Compressor Assembly Figure 1 1 Coach Cutaway View 424 329 1 2 GENERAL DESCRIPTION 1 2 1 Condenser Assembly The condenser assembly See Figure 1 2 includes a condenser coil fan and motor assemblies filter drier sight glass liquid line solenoid valve s king valves and an ambient temperature sensor The condenser coil provides a heat transfer surface for condensing refrigerant gas at a high temperature and pressure into a liquid at 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 tubes this results in condensing the refrigerant into a liquid The filter drier m 7 e removes moisture and other noncondensibles from the liquid refrigerant before it enters the thermal expansion valves in the evaporator assemblies The condenser is also fitted with a fusible plug which protects the system from unsafe high temperatures The main evap
99. y system to the unit at the condenser service King valve to remove refrigerant charge See Figure 4 4 Refer to instructions provided by the manufacturer of the refrigerant recovery system NOTE 1 Before opening up any part of the system a slight positive pressure should be indicated on the gauge When opening up the refrigerant system certain parts may frost Allow the part to warm to ambient temperature before dismantling this avoids internal condensation which puts moisture into the system When opening or closing the service valves care should be given to note if the packing around the valve stem is worn or may need adjustment to prevent refrigerant leaks 4 4 3 Refrigerant Removal From An Inoperative Compressor To remove the refrigerant from a compressor that is not operational do the following a Attach a manifold gauge set as shown in Figure 4 3 and isolate the compressor by front seating the suction and discharge valves Recover refrigerant with a refrigerant reclaimer If the discharge service valve port is not accessible it will be necessary to recover refrigerant through the suction service valve port only C Service or replace components as required and leak check the compressor Using refrigerant hoses designed for vacuum service connect a vacuum pump to center connection of manifold gauge set Evacuate compressor to 500 microns Close off pump valve isolate vacuum gauge and pump

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