MicroTech II - Service Manual
Contents
1. 11 T 11 12 PEA TOn E O 12 LIMITATIONS wert udo BE o NR at eda dace a a leds inact ta esas 12 NN 13 RPP SS 14 PROBE nd md md nd nr DR DURER 15 CONDENSATION CONTROL WITH CUT ENABLING 16 Via res od eee 16 Becr euo TTE TTE 16 PY TP RE Ze REGULATION E inte beset E A E PUER a s dvr TEE DI FETU IE PITE I TE A ETT 17 ELECIRONALVE MANAGEMENT 18 e EL Um 18 WATER PRESSURE CONTROL FOR PFS UNITS strata er aer renta sae esee im 20 CONTROL LOGIC OF THE COOLING TOWER FOR PFS isoaxantatssrimixisvx atv att dax taxa aaa mda maa etam ia 22 GORIDIBSSORL essa a E id estin ru xta a t cina a prinia 22 do 23 CONTROL LOGIC OF THE S WAY VALVE FOR PFS UNITS2. MicroTech II Control Forced Unloading Used inputs e Outlet Temperature B2 e pressure B7 Used Parameters e PreventThreshold of high temperature on discharge e High pressure Threshold e High pressure Differential e Antifreeze temperature Threshold e Antifreeze Differential Used Outputs e Unload Solenoids Principles of working Forced unload avoids the compressor to reach conditions of pressure able to lock it in alarm condition Compressor is forced to unload when e high pressure threshold is reached e antifreeze temperature threshold is reached Hold Phase hold pressure standby of compr by high pressure During compressor load if pressure reaches a reference value Dprevent Selectable by keypad under manufacturer psw controller holds compressor atthe load currently reached N B that situation is not an alarm not even a warning thus no message will appear on the display but a symbol will be displayed for Service personnel see mask information for further details Decrease Phase unloading pressure pressure warning If pressure in spite of the phase of hold pressure is still increasing until a new reference value Dwaming Selectable by keypad under manufacturer psw controller will force compressor to unload until a pressure value Dwaming diff will be reached Also diff is keypad selectable in the same mask Of Pwaming under manufacturer psw N B that situation is a warni
3. 23 l N 24 SENERAI DESCRIPTIO CURED CURRERE RR 24 EE 24 PUP RI 25 26 NETWORK eC 27 e EIER 27 28 28 Terminal configuration 3 29 Display of the terminal connection 30 Release 1 0 01 05 01 page 2 2 Service Manual Preliminary Version 0 7 Applications and functions carried out by the system Type of controlled units air water only chiller air water chiller heat pump Compressor maximum number Max 1 compressor for MicroTech II card with max 4 MicroTech II card capacity controls Compressor type Screw compressors Compressor call rotation Rotation of all the compressors with FIFO logic Electronic expansion valve management EXV Management of the EX7 and EX8 Alco valve Safety for each refrigeration circuit High pressure pressure switch
4. AL36 DamagedprbeB7 o Jeat X j60sc AL37 DamagedprbeB8 Jat j60sc AO Pump maintenance CTC mn 1 Compressor 1 maintenance y LE AL42 Compressor2maintenance To y jmn ALSO Offineuntl CE to 30e ALS Offineunt2 Eto 30sec AL54 Evaporator fan thermal o o E Mj AL55 Damaged 32k clockcard DRIVERI __ d 160 Driverl Probe error mamn Selectable CS AL61 Drivel Stepmotorerr J J jme AL62 Driverl Eepromeror ss Circuit man selectable AL63 Drivel Batteryeror Cicut _ selectable 64 Driverl High pressure mae Selectable ti FAL65 Driverl Lowpressure Cd Circuit Selectable Enabling AL66 Driverl SuperHeat o ma jseecabe AL67 Driver Valvenotclsedduringstop man 7 AL68 Driverl waitforvalvereopening dema 169 Driverl waitforbatteryrecharge
5. AL70 Driver waitfor eeprom restat man DRMR2 _ __ __ 180 Drive2 Probeemr jselectbe ALBI Driver2 Step motorerror Cieut T ma y AL82 Drive2 Eepromeror j Cicut ma jseletbe CC AL83 Driver2 Bateyerr man AL84 Driver2 Highpressure _ mae selectable CCS AL85 Driver2 Lowpressue j Cicut ma selectable Enabing AL86 Driver2 Super Heat o AL87 Drive2 Valve not closed during stop I AL88 Drive2 waitforvaverepenng mam AL89 Driver2 wait for battery recharge ma y AL90 Driver2 waitforeepromrestat O l o o man E Release 1 0 01 05 01 page 25 25 Service Manual Preliminary Version nelle aA MicroTech II Control Driver alarms The alarms coming from the driver cards also report the indication of the driver that has generated the alarm in the example D 3 Example m Drv AL60 ouperheat alarm When an alarm mask appears relative to the driver card above left the writing Driver appears furthermore on the right D indicates the driver whilst U indicates
6. Code Alarm Description Compressor Fan Pump System Reset Delay Enabling o Off Off Off _ auto man CE es l LL ALO1 Severe alarm no enabling both master and slave Antifreeze alarm resetting mode can be set by user default 15 manual i ino 04 master and slave AL06 selectable 0 0 ALIO Low pressure pressure swith selectable i AL11 Low pressure pressure switch Cirutt2 selectable AL12 High pressure pressure switch1 P Cicutl ALI3 High pressure pressure Cirut2 nooo ALI4 pressure switch Ciruit selectable ALIS Oil differential pressure switch2 Cirut2 selectable AL16_ Compressorlthermal Compl jn AL17 Compressor 2 thermal Comp2 nooo AL20 Fanithermal CT nooo AL21 Fan2thermal CE jn AL2 Fan3thermal jo 60sec 60sec f 0 0 0 0 0 0 7j AL32 Damaged probe B3 _ 60sc AL33 Damaged probe B4 Jat j 60sc AL3 Damaged probe B5 o Jat o j 60sc AL35 DamagedprbeBO _ j 60sc
7. Preliminary Version nelle MicroTech II Control Compressor Rotation The compressor call rotation causes the hour number and the start stop number of different compressors to be equivalent Rotation is carried out according to a FIFO type logic this means that the first compressor to start will be the first to stop As a consequence of this behaviour remarkable differences could occur in the initial phase as regards the working hours of the various compressors but at full working such differences will increasingly attenuate The rotation only involves the compressors not the capacity controls Compressor rotation can be disabled using the appropriate parameter Management without rotation e Start C1 C2 C3 C4 C5 C6 C16 e Stop C16 C15 C14 C13 C12 C11 C1 Management with FIFO rotation the first compressor to start will be the first to stop Start C1 C2 C3 C4 C5 C6 C16 e Stop C1 C2 C3 C4 C5 C16 Release 1 0 01 05 01 page 14 14 Service Manual Preliminary Version nelle MicroTech I Control Condensation regulation Condensation can be carried out as follows e on off bound to the compressor working without the pressure transducers e on off or modulating bound to the reading of the pressure transducer if the high pressure transducers have been enabled e on off or modulating bound to the reading of the battery 1 and 2 temperature probes 1 and 2 if the battery temperature
8. Contactor Line Contactor Star Contactor Delta Time between Line and star Star Duration Limitations at compressor start MicroTech II Control Time between star and delta Two kind of limitations at the start are considered both allow compressor to start with delta contactor by passing star contactor Enabling is the same for both in the following cases 1 When specific values for high and low pressure are over selectable by mask 2 When threshold of equalized pressure is over selectable by mask In the software this pressure is the average between low and high pressure Release 1 0 01 05 01 page 12 12 Service Manual Preliminary Version Sg t PUMP DOWN Management Pump down function is executed at compressor shutdown It ends due to the low pressure switch or in case this faults for maximal time Pumpdown Used Inputs e pressure transducer Used Parameters e Pump down type e Pump down enabling by switch with unit off e Pump down Setpoint in fix mode disabling e Pump down MaxTime Used Outputs e Liquid Solenoid Valve If enabled pump down arrives either when compressor stops by logic either when unit is stopped by ON OFF switch Its time is selectable and it can end for max time or by pressure switch In case of alarm stopping the unit or the compressor pump down ends immediately Release 1 0 01 05 01 MicroTech II Control page 13 13 Service Manual
9. Low pressure pressure switch Oil differential pressure switch Compressor thermal Condensation fan thermal High Discharge Temperature on the compressor Phase Monitor Star Delta Transition Failed Low Delta Pressure between Suction and Discharge S ystem security A serious alarm input stops the whole unit available both in the MASTER and SLAVE unit A flow controller input stops the whole unit available both in the MASTER and SLAVE unit A pump thermal input stops the whole unit Remote on off input without alarm signaling Regulation type Proportional or proportional integral regulation on the evaporator input probe Condensation The condensation can be carried out according to temperature or pressure The fans can be managed according to ON OFF mode Or with a 0 10 V modulating signal Accessories Supervision with RS 422 R S485 serial card EVD driver backup EVBAT battery module Release 1 0 01 05 01 MicroTech II Control page 3 3 Service Manual Preliminary Version nelle MicroTech II Control Master slave system architecture The system is composed of at least two up to four MicroTech Ils connected to the local network of which the first acts as master and the following act as slaves Master function Temperature regulation All compressor call Manages the system alarms Management of a refrigeration circuit start stop alarms EXV Communication possibility with an external super
10. LA MicroTech II Control Regulation Outlet temperature regulation CONTINUOUS UNLOADING Used Inputs e Inlet Temperature e Outlet Temperature Used Parameters e Regulation Setpoint e Outlet temperature Regulation Band e Continuous unloading Dead Band Dead band e Pulse Period Minimum Pulse Time for solenoid 1 Maximum Pulse Time for solenoid 1 Minimum Pulse Time for solenoid 2 Maximum Pulse Time for solenoid 2 Enabling to continuous power ramp up Time of forced ON for solenoids before compressor start up Used outputs e Digital Output n 6 for solenoid 1 e Digital Output n 7 for solenoid 2 Principles of working Continuous unloading uses 2 solenoids to control screw compressor slide and thus its capacity control is performed by outlet temperature Logic of solenoids is selectable by mask the following table shows the default configuration SOLENOID A SOLENOID B COMPRESSOR BEHAVIOR OFF fixed ON Compressor just started o in forced power decrease OFF ON pulsating Floating power decrease fixed OFF fixed OFF Dead band with system in pause ON pulsating ON pulsating Floating power increase ON fixed solenoid is always ON not pulsating OFF fixed solenoid is always OFF not pulsating ON solenoid floats with a trend toward the state of ON fixed OFF solenoid floats with a trend toward the state of OFF fixed In the graphic is sketched the mode of working of the unload solenoids Slide moves by pulses of i
11. is requested to allow the unit to work with a reduce noise level In those units it 5 needed to limit the number of spins of the fans until an assigned pressure of condensation Whenever the pressure of condensation goes over the allowed limit controller will release the maximum signal speeding up fans until the maximum regime of rotation Here below a table explaining the graphic following LE e MicroTech Il Reference Inverter Differential Differential Value the controller is releasing the maximum proportional signal reference 10 vdc That value added to the value of the point A gives the pressure of max rotation speed for the fans NN M Point of transition for the relay of the 1 fan of each circuit for disabling the work of the fan speed regulator fans off BEEN EN NM Point of transition for the Ha of the 1 fan of each circuit for the work of the fan speed regulator fans on OUS FE reste tere fan speed pressure where fan speed changes maximum signal us control of the rotation speed of the fans Set high pressure switch Set Point of the high pressure switch Volt A C D B E bar In the case a regulation with cut enabling is not requested to have a simple continuous fan regulation based on a proportional signal following the condensation pressure set as follows under Manufacturer psw points B E F e F 10 Volts xxx bar Release 1 0 01 05 01 pa
12. outlet delayed at the start and at full function e Evaporator antifreeze alarm probe function in evaporator outlet with operation set and reset differential with manual reset e Digital input serious alarm unit immediate stop with manual reset The reset of the alarms is executed by pressing twice the alarm button No driver alarm is of the serious type Alarm historical If you use the clock card having the MICROTECH IICLKMEMO code with eeprom 32K it will be possible to have a historical of the last 900 alarms being occurred There are two masks of the alarm historical one which displays the chiller parameters setpoint band inlet temperature and outlet temperature stored when an alarm occurs and another one that displays the driver parameters superheat pressure temperature and valve position stored as soon as an alarm takes place For each alarm it is possible to store Mask 1 CHILLER Code of the activated alarm Date and hour of the activation Regulation setpoint Regulation band Inlet temperature Outlet temperature Mask 2 DRIVER Code of the activated alarm Date and hour of the activation S uper heat temperature Valve position in steps Pressure from driver Temperature from driver The data of this historical remain stored in the eeprom of the above mentioned card Release 1 0 01 05 01 page 24 24 Service Manual Preliminary Version MeQuay LA MicroTech Il Control Alarm table
13. probes have been enabled Used inputs high pressure probe C1 B7 high pressure probe C2 B8 battery temperature probe C1 B3 battery temperature probe C2 B4 Used outputs Fan 1 Fan 2 Fan 3 C1 AOUT fan speed regulation C2 AOUT2 fan speed regulation Used parameters Condensation control selection none pressure temperature Type of condensation battery Single Separated Condensation S et P oint Condensation Band Number of fans for battery P revent function enabling P revent threshold P revent differential Output voltage relevant to the inverter minimum speed Output voltage relevant to the inverter maximum speed S peed up time inverter On off condensation connected to the compressor working With this type of condensation the fan working will be subordinated solely to the compressor working Stopped compressor stopped fan Started compressor started fan On off condensation connected to the temperature or pressure sensor With this type of condensation the fan working will be subordinated solely to the compressor working and to the value read by the pressure or temperature sensors as a function of a set and of a band When the pressure temperature will be lower or equal to the set all the fans will be stopped when the pressure temperature increases up to set band all the fans will be started It will be possible to select condensation with single battery or with separated battery with the single battery condens
14. the MicroTech Il card connected to the driver indicated In the example the alarm comes from the driver no 3 which is connected via pLAN to the MicroTech Il card no 2 This numeration is relative to the allo connection diagram explained above and successively proposed again thermoregulation probe of all the system L Terminal LCD 4x20 Short summary of the driver card alarms probe error malfunctioning or failure of the temperature and or pressure probe step motor error valve motor connection damage eeprom error writing or reading eeprom malfunction battery error battery malfunction high pressure on the EXV driver the operating pressure has exceeded the MOP max threshold low pressure on the EXV driver the operating pressure has exceeded the LOP min threshold superheat alarm valve not closed during stop valve not completely closed after the last blackout waitfor valve reopening warning wait for valve complete closing in order to restart correctly wait for battery recharge warning wait for battery recharge wait for eeprom restart warning wait for eeprom restart See the mask list at the end of the manual for more information Furthermore it is possible to stop the circuit compressor s when the relative driver reports the alarm battery error and or low pressure mode for EXV driver LOP mode It is also possible to enter a delay for the last alar
15. 1 2diff on 2 Step off Stp Stp diff e Three steps Control The first relay is enabled when reached the value of the Setpoint 1 3 of the differential The second step is enabled when reached the value of Setpoint 2 3 of the differential The third step is enabled when reached the value of Setpoint the differential Steps will be disabled as per the following schematic on 1 Step off Spt 1 3 diff on 2 Step off Spt 2 3 diff on 3 Step off S pt Spt 1 3 diff N B the number of steps controlling the cooling tower is selectable by keypad under User password Release 1 0 01 05 01 page 22 22 Service Manual Preliminary Version MeQuay LA MicroTech II Control PFS with two Compressors Used Inputs e Condenser inlet water Temperature Used Parameters e Setpoint Insertion Tower Steps e Insertion Differential e Number of Available Tower Steps Used Outputs e First Step Cooling Tower OD12 Second Step Cooling Tower OD13 e Third Step Cooling Tower OD08 Units with two compressors install two MicroTech Il cards connected in network Each card owns three digital outputs for tower control Thus the maximum number of steps is six Control logic is similar to the three steps control as previously specified In the case is requested to enable from 4 to 6 steps the three digital outputs OD12 OD13 and OD08 of the SLAVE card will be enabled Control logic is as previously specified Differential is
16. Service Manual Preliminary Version McQuay Italia S p A MCQUAY Microfech ll Control pLAN Driver for Modular Chillers McQuay ALS WHS PFS With screw compressors 1 to 4 circuits Helease of the Manual 1 0 01 05 2001 Service Manual Preliminary Version MeQuay LA MicroTech II Control Contents APPLICATIONS AND FUNCTIONS CARRIED OUT BY THE SYSTEM 3 MASTER SLAVE SYSTEM ARCHITECTURE n 4 EIS mim q mmm mmm mi NU mu 5 AIR WATER UNIT WITH MAX 4 SCREW COMPRESSORS MCQUAY ALS WHS sssssssee enne 5 WATER WATER UNIT WITH MAX 2 SCREW COMPRESSORS MCQUAY PES 6 ee ee eee ee eu eeu ee eu eeu ee ea eee ea ta eeu ea ea eeu ea ea eee ee ea ee ee ea eee ee eae ee ea eee ee eu eee ee ea ea ee eu eu ee en eeu ee nn cde dn dud 7 OUTLET TEMPERATURE 7 CONTINUOUS E E E 7 sitse meu eso uem Forced WIM OAM vicar 10 START UP OF A SINGLE
17. als on the contrary if a shared terminal exists the latter will be updated only if the involved MicroTech II have presently its control From the logical point of view the following diagram is valid PRIVATE PRIVATE MicroTech Il l SHARED i MicroTech MicroTech ll PRIVATE _ e n example the shared terminal is associated with 4 1 0 cards but in the example only the 2 can display data and receive keypad commands from it The switching between cards takes place in a cyclic sequence 1 52 53 54 51 by pressing the button or a combination of two to which this function has been assigned e The communication can also occur automatically upon direct request of the program For instance a 1 0 card can request the control of the shared to display alarms or on the contrary give it to the following one at a precise established time cyclic rotation Release 1 0 01 05 01 page 28 28 Service Manual Preliminary Version MeQuay LA MicroTech Il Control The number and type of terminals is established during the initial network configuration The relevant data are stored in the EEPROM memory of each single 1 0 card Terminal configuration procedure The first operation to be performed when for the fist time a pLAN network is to be started or an 1 0 is replaced is the activation of the terminal configuration procedure Before beginning such procedure make sure tha
18. ation the fans will be controlled by the higher pressure temperature with the separated battery condensation each sensor of pressure temperature controls its own fan Modulating condensation connected to the pressure or temperature sensor With this type of condensation the fan control will be carried out through a 0 10 V analog output proportional to the request of the pressure temperature sensors Also in this case it will be possible to select condensation with single battery or with separated batteries Control will be identical with the above one If the lower limit of the ramp is greater than OV we will not have a proportional straight line but as in the first part of the graph one step below the dif Set P oint 10 Volt 0 Volt DANG Prevent Alarm high pressure Threshold batt temperature Prevent Function That function selectable under Manufacturer password 15 to avoid the circuits stop for high pressure When this threshold is reached with compressor on compressor is forced to unload until the pressure falls down the setpoint a selectable differential Release 1 0 01 05 01 page 15 15 Service Manual Preliminary Version MeQuay LA MicroTech Il Control When this threshold is reached with compressor on fans are forced on until the pressure falls down the setpoint a selectable differential Condensation Control with cut enabling This logic is applied to the units where the continuous speed control
19. ded into three categories e Only signalling alarms only display and buzzer signalling signalling on display buzzer alarm relay e Circuit alarms deactivate only the relative circuit signalling on display buzzer alarm relay e Serious alarm deactivates the entire system signalling on display buzzer alarm relay Only signalling alarms e Unit maintenance alarm e Compressor maintenance alarm e Damaged or disconnected clock card alarm e Mains disconnected unit alarm e Driver alarms driver high pressure super heat and absence of valve closing during the last stop not closed valve during stop Circuit alarm e High pressure press contr alarm immediate compressor stop with manual reset e pressure alarm delayed at the compressor start immediate full function manual reset e Compressor thermal alarm immediate compressor stop with manual reset e 11 differential alarm delayed atthe acquisition with manual reset Fan thermal alarm immediate fan stop with manual reset e Driver probe error alarm stop compressor s of the relative circuit e Driver motor error alarm stop compressor s of the relative circuit e Driver eeprom error alarm stop compressor s of the relative circuit e Driver battery malfunct alarm stop compressor s of the relative circuit can be enabled e Driver low pressure alarm stop compressor s of the relative circuit can be enabled and delayed Serious alarms e Water flow failure alarm digital
20. divided per the number of steps selectable by keypad Each step is inserted based on the temperature of the inlet water reaching the value of Spt diff n grad Control Logic of the 3 way valve for PFS units Used Inputs e Condenser inlet water Temperature Used Parameters e Setpoint on Condenser Temperature on the zero voltage scale e Differential of Full Scale Used Outputs e Analog Signal of Control Valve 0 10V YO The control system of the cooling water on the condenser can be done also by a three way bypass valve That valve installed by the Customer be controlled through a 0 10V analog signal from the output YO of the MASTER card By keypad it is possible to introduce the Setpoint of condenser return water temperature corresponding to an output of 0 volt More a temperature differential has to be settled corresponding to a signal of 10 volt To set the valve a percentage of minimum valve opening has to be selected es 10 corresponding to 1 volt output and a percentage of maximum valve opening es 90 corresponding to 9 volt output Logic is similar to that of the inverter control on air cooled units 10 V 10096 Max valve opening keypad selectable Min valve opening keypad selectable 0 V 0 Stp C Stp Diff C Release 1 0 01 05 01 page 23 23 Service Manual Preliminary Version nelle MicroTech II Control ALARMS General description The alarms will be divi
21. e compressor with partial capacity will start decrease When stopped one by one the remaining compressors will shut down as described b Assume the temperature is in the zone of floating decrease and one compressor is in phase of decrease If temperature goes up suddenly over point E that compressor will start decreasing even if it has needed before to reach the maximal power Release 1 0 01 05 01 page 8 8 Service Manual Preliminary Version MeQuay EA MicroTech II Control In program masks will be selectable Output Setpoint of the regulation User Menu Point B Temperature Band for output regulation User Menu 3 between B and E Neutral Band to control continuous unloading User Menu gt between C and D Solenoid Configuration for the phase of stand by Solenoid Configuration for the phase of increase Solenoid Configuration for the of decrease Period pulses Manufacturer Menu Max and Min Duration of pulses on solenoids 1 and 2 Manufacturer Menu Time of forced ON of solenoids at compressor start Manufacturer Menu Duration Of the pulse Pulse Period Pulse period Pulse period MASTER card controls the effective start and stop of the compressors and the rotation by the ordinary regulation in output the handling of the relays of unload is done by each SLAVE controlling the continuous unload of the corresponding compressor Release 1 0 01 05 01 page 9 9 Service Manual Preliminary Version Manuas
22. ge 16 16 Service Manual Preliminary Version MeQuay LA MicroTech II Control Antifreeze regulation Used inputs e Output temperature probe Used parameters output probe enabling antifreeze heater Set Point antifreeze heater differential antifreeze alarm S et P oint antifreeze alarm differential Used outputs e antifreeze heater Each MicroTech Il unit can manage the antifreeze regulation provided that the output temperature probe is connected and enabled Antifreeze alarm activation Antifreeze heater activation Antifreeze diff Heater diff Antifreeze set Heater Set The antifreeze regulation is always energized also when the machine is OFF both summer working and winter working Note the antifreeze alarm on any MicroTech Il unit stops the entire machine Release 1 0 01 05 01 page 17 17 Service Manual Preliminary Version MeQuay MicroTech II Control Electro valve Management This software is configured to handle only the E lectro valve liquid injection Used Inputs Discharge Temperature B4 Used Parameters Enabling threshold electro valve differential electro valve Inihibited Outputs Economizer solenoid Valve oil cooler liquid injection Working Description Electro valves are activated based on the discharge temperature of the compressor as showed in the graphic Enabling threshold Discharge temperature of the compressor Enabling thresho
23. hat on working temperature of cooling water will decrease excessively for example due to an anomalous control of the cooling tower In this case the compression ratio could go down the minimum limit of 2 0 The controller will react by controlling the compression ratio as previously described Compression ratio will be controlled back between 2 1 and 2 3 playing on the control of the expansion valve Release 1 0 01 05 01 page 21 21 Service Manual Preliminary Version MeQuay MicroTech II Control Control Logic of the cooling tower for PFS PFS with single compressor Used Inputs Condenser inlet water Temperature Used Parameters e Setpoint Insertion Tower Steps e Insertion Differential e Number of Available Tower Steps Used Outputs e FirstStep Cooling Tower OD12 Second Step Cooling Tower OD13 e Third Step Cooling Tower OD08 Control logic must be proportional to the input in the following way e step control the first relay is enabled when reached the value of setpoint the differential The relay is disabled when temperature goes down the setpoint es Spt 30 C Diff 25 C Tecc 35 C Tdisecc 29 9 C on off Stp Stp tiff e Two steps Control The first relay is enabled when reached the value of setpoint half differential The second step 15 enabled when reached the value of setpoint the differential Steps will be disabled as per the following schematic on 1 Step off Stp Stp
24. ld electro valve Liquid injection 85 C Differential 10 Release 1 0 01 05 01 page 18 18 Service Manual Preliminary Version Sg t Regulation on water water units chiller only Used inputs Evaporator Inlet Temperature Evaporator Outlet Temperature Condenser Inlet Temperature Condenser Outlet Temperature Used Outputs e Compressors e Digital Output n 6 for solenoid 1 e Digital Output n 7 for solenoid 2 Used Parameters Unit type Special features of working 1 Water Pressure Control 2 Tower Control on Condenser Line 3 Three Way Valve Control on Condenser Line Release 1 0 01 05 01 MicroTech II Control page 19 19 Service Manual Preliminary Version Huila MicroTech II Control Water pressure control for PFS units Used Inputs condenser inlet water temperature e evaporator inlet water temperature Used Parameters e Setpoint of First Opening in Cold Start e Setpoint of High Discharge Superheat Used Outputs e Driver EXV8 Valve e Compressor Output e Liquid injection solenoid Cold Normal Start Start P1 P re Start 1 6 Valve Valve Closing Dead Band Opening Cold Start Reverse to 21 23 WPC Normal Logic gt On Working 2 0 P re start Input values are converted in pressure based on the internal pressure temperature table e fthe ratio of these pressures is upper than 1 6 the controller will start compressors fo
25. ling Evaporator flow controller enabling Evaporator flow controller enabling Evaporator flow controller enabling Remote On Off enabling U T U ing U U 0 Phase Monitor enabling Phase Monitor enabling Phase Monitor enabling Phase Monitor enabling Double Setpoint Analog inputs Only Chir uni ed UNIT 2 Slave n 1 UNIT 3 Slave n 2 UNIT 4 Slave 3 Digital outputs Only Chiller unit UNIT 2 Slave n 1 UNIT 3 Slave n 2 UNIT 4 Slave n 3 Unloaderlcomp lC Unloaderlcomp2C Unloadericompj3C jUnloaderlcomp4C Circuit 1 condens Fan 1 Circuit 2 condens Fan 1 Circuit 3 condens Fan 1 Circuit 4 condens Fan 1 Circuit 1 condens Fan 2 Circuit 2 condens Fan 2 Circuit 3 condens Fan 2 Circuit 4 condens Fan 2 Unloader 1 comp 1 C Liquid Inj 1 Liquid Inj 2 Liquid Inj 3 Liquid Inj 4 Unloader 1 comp 2 C Unloader 1 comp 3 C 4 Unloader 2 1 5 Unloader 2 comp 2 5 Unloader 2 comp 3 5 Unloader 2 comp 4 S Circuit 1 condens Fan 3 Circuit 2 condens Fan 3 Circuit 3 condens Fan 3 Circuit 4 condens Fan 3 Analog outputs OnlyChillerunit UNIT 1 Master UNIT 2 Slave 1 UNIT 3 Slave 2 UNIT 4 Slave 3 Condens fan speed reg 1 Condens fan speed reg 2 Condens fan speed reg 3 Condens fan speed reg 4 Release 1 0 01 05 01 page 5 5 Service Manual Preliminary Version MeQuay LA MicroTech Il Control WATER WATER Unit with max 2 sc
26. llowing the normal start procedure e ratio is lower than 1 6 the controller will start compressors following a logic of cold start Cold Start Controller opens the expansion valve at 20 value selectable by keypad and it starts compressor Instead of controlling the superheat MicroTech Il checks for compression ratio absolute discharge pressure absolute evaporation pressure opening or closing the expansion valve to maintain that ratio between 2 1 and 2 3 If that ratio goes down 2 1 controller closes the valve if the ratio goes over 2 3 opens it Between these values the valve will remain steady dead band During the WPC superheat and subcooling will reach very high values but they will be ignored there is no alarm of low high superheat While evaporator and condenser water temperatures approach design conditions the value of suction superheat decreases continuously Cold start can be considered at the end when suction superheat reaches 2 C A this point control is left to the Alco driver targeting suction superheat around 0 5 C During cold start the following anomalous conditions can happen 1 Low suction pressure If electronic expansion valve closes excessively to ensure the minimum compression ratio it is possible the suction pressure goes down the freeze value In that case controller will reduce load of the compressor s until the suction pressure will come back at least at 0 C In case that situation is not
27. m the default is alarm enabled with a 0 second delay m manuf 246 Drv Driver alarms iotop driver 2 compressors if in lerr of battery N Release 1 0 01 05 01 page 26 26 Service Manual Preliminary Version MeQuay EA MicroTech II Control pLAN network All the devices connected to the pLAN network are identified through their own address If the same address is assigned to several units the network can not operate Since terminals and MicroTech II 1 0 cards utilise the same type of addressing terminals and MicroTech II cards with the same identifier cannot exist The values selectable for the address range from 1 to 16 as to the terminals and from 1 to 16 with regard to the I O cards The overall number of peripherals that can be connected t the network is 16 Actually maximum combinations can be 8 terminals 8 1 0 cards 1 terminal 15 cards etc The addresses are set up for the terminals through the dipswitches placed on the back whereas for the I O cards the network option card 15 required I O card address Network option card MICROTECH 0000 MICROTECH The network option card 15 available in two versions only dipswitch and LED Cod MICROTECH IIADR0000 dipswitch LED and calendar clock Cod MICROTECH Such card is indispensable for the network operation of the MicroTech II 1 0 cards also if only one MicroTech Il board is used The following table rep
28. ncreasing or decreasing time depending on the system 15 in the zone of increasing or decreasing power The only data to be inserted by the user is the Dead Band inside the Outlet temperature Regulation Band all remaining thresholds will be calculated automatically by the software Outlet temperature Regulation Band Stop comp with Floating decrease dead band reg Dead band Floating increase A B D E Setpoint Release 1 0 01 05 01 page 7 7 Service Manual Preliminary Version Hula V A MicroTech II Control Logic of the Continuous unloading through the points of the graphic Compressors will start when temperature will be higher than the upper end of the neutral zone Setpoint band Consequently compressors will start after point E and increasing pulses will have the maximal duration At compressors start discharge is forced for a selectable time Temperature higher than point E compressor start Compressor start is controlled by the values of outlet water temperature they start in sequence with a selectable interstage requested to reach the full power increasing power by pulses of maximal duration After this time compressor is assumed at the top of the power consequently each device will continue to work at the reached power Temperature between D and E zone of floating increase In that temperature band only the last compressor started will float in increase of power for an i
29. nfinite time unless it reaches full conditions The remaining compressors keep working on the reached power value Modulation pulses will have variable duration based on the temperature Temperature between D and C neutral zone In the neutral zone logic remain in stand by and all compressors keep working on the reached power value Temperature between C and B zone of floating decrease e With compressors rotation all compressors go in stand by except for the first started starting to float in decrease with pulses of duration increasing with the temperature decrease e Without compressors rotation all compressors go in stand by except for the last started starting to float in decrease with pulses of duration increasing with the temperature decrease Temperature under point B compressors shutdown When temperature falls down point B regulation Setpoint compressors start floating in decrease with pulses of maximal duration the real shutdown arrives after a selectable interstage to assume compressor is arrived at minimum power Description of the Logic based on Temperature models without capacity sensor temperature increase When outlet temperature exceeds point E the first compressor is starter floating in increase with maximal pulse duration Assumed temperature keeps over point E increase will continue for a selected time until we can consider compressor at full capacity At this point the second compressor will be reque
30. ng not an alarm thus no message will appear on the display but a symbol will be displayed for Service personnel see mask information for further details High pressure Phase high pressure When reached the high pressure value selectable by keypad under manufacturer psw controller goes in alarm stops compressor without pumpdown and sends a message of alarm on the display Logic is described on the following graphics a high pressure threshold High pressure Differential antifreeze temp threshold Outlet Temperature Differential Release 1 0 01 05 01 page 10 10 Service Manual Preliminary Version SF 0 7 s p a Start up of a single compressor Used inputs e Thermostat inlet temperature Used Parameters e Delay time to start Used Outputs e Fan group e Liquid solenoid Valve e Compressor Description of the logic Start phases are described in the following graphic THERMOSTAT LIQUID SOLENOID FAN GROUP COMPRESSOR Delay to Start Release 1 0 01 05 01 MicroTech II Control page 11 11 Service Manual Preliminary Version alia S p A Start of the compressor motor Used Inputs e Inlet Temperature Used Parameters e Time between star and line e Star pulse duration e Time between star and delta Outputs used e Contactor Line e Contactor Star e Contactor Delta Description of the Logic Motor star is described in the following diagram
31. orts dipswitch codify for pLAN address from 1 to 16 Swl m L dee In the standard application EPSTDEMCHA modular chiller addresses for the MicroTech Il units 1 2 3 hr hr Release 1 0 01 05 01 page 27 27 Service Manual Preliminary Version MeQuay LA MicroTech II Control Terminal address Terminal card viewed from behind Microprocessore On DOCU ek Off Dip switch 12345678 Conn Conn stampante rete locale The address of the terminals is set up through the dipswitch bench found on the back The address is selectable in the 1 16 range by utilising the 1 5 dipswitch The address value is obtained via the following table see also previous paragraph The terminal of the 4 relay MicroTech II units must have an address greater than 5 Unit terminal mE n 1 2 3 4 H H H H Address 5 dip switches Terminal management e Each MicroTech II card connected to the network can manage several terminals max 3 The display on them occurs simultaneously and not independently it the same thing as having keypads and displays connected in parallel Each terminal associated to a certain card can be private or shared A terminal 15 said to be private if it displays exclusively the output of an I O card A terminal is said to be shared if automatically or through keypad may be switched between several control cards Each MicroTech Il keeps constantly updated the display of the private termin
32. pletely the display and shows the message 1 0 Board xx fault e fthe terminal does not receive the message of network synchronisation token for more than 10 sec it clears completely the display and scows the message NO LINK e this is equivalent to the condition of OFF green LED for the I O cards Display of the network state Net TAT e n the program there is a procedure can be activated only in the LCD version that allows the display in real time the state and type of the peripherals actually being connected e Such procedure is activated by the simultaneous pressure of the 0 1 2 buttons or else Up Down Enter for at least 10 sec after the elapse of the first 5 sec you obviously enter the terminal configuration procedure The mask displayed is the following e The number after T indicates the address of the terminal on which the procedure is activated the symbols indicate the type of peripheral terminal MicroTech Il and the respective address e example the network turns out to be composed of MicroTech Il cards with address 1 2 and of 3 terminals with address 3 4 15 Release 1 0 01 05 01 page 30 30 Service Manual Preliminary Version MeQuay LA MicroTech II Control Release 1 0 01 05 01 page 31 31
33. rew compressors McQuay PFS Digital inputs Only Chiller unit MACHINE TYPE 3 UNIT 1 Master UNIT 2 Slave On Off by Main S witch On Off by Main S witch Evaporator flow controller enabling Evaporator flow controller enabling ing N e Oidfeental Oildfferental 3 Failed trans Y A Failed trans Y A High pressure switch 1 High pressure switch 2 Comp thermal 1 Comp thermal 2 U Phase Monitor enabling Phase Monitor enabling Double Setpoint U U Analog inputs Only Chiller unit n UNIT 1 Master UNIT 2 Slave 4 ComplOiTemp Com20iTem oipifTrnducerCici OiDifTnsduerCic2 7 SewontResetOverie Demand High pressure transducer 7 Volage amp mps E ComprCapactySensorcic 1 Compr Capacity Sensor crc Digital outputs Only Chiller unit N jUNITi Master UNIT 2 Slave 1 Circulationpump TN 2 Line Contactorcomp 1 Line Contactorcomp 2 4 Delta Contactor comp 1 Delta Contactor comp 2 6 Unloader 1 comp 1 C Unloadericomp2C 8 Circuit 1 condens Tower fan3 Circuit 2 condens Towerfan3 9 liquidi ds Liquid in 2 oT NU NU General alarm cumulat General alarm cumulat 10 11 12 Analog outputs n 1 Master UNIT 2 Slave LAN 1 Condens Tower fan speed reg 1 Condens Tower fan speed reg 2 Release 1 0 01 05 01 page 6 6 Service Manual Preliminary Version MeQuay
34. s OFF and master is ON the slave does not starts If the slave is ON andt master is OFF the slave does not start e The drivers have no start enabling are always ON this does not mean that the driver begins immediately to control because as long as the MicroTech Il units do not cause at least one compressor to start the driver continues to receive a 0 request and consequently the valve is kept closed Release 1 0 01 05 01 page 4 4 Service Manual Preliminary Version MeQuay LA MicroTech Il Control Input output list Below the inputs and outputs are listed as a function of the unit type a number has been associated to each type of machine This number is the principal parameter of the program as it identifies the input and output configuration In this way the configuration of the machine is made very easy because you need only choose the requested input and output list and select the associated number in the program configuration masks Each of the following pages contains 2 unit types and for each unit the MicroTech II inputs outputs from master and the inputs outputs of one of the slave MicroTech lls are described AIR WATER Unit with max 4 screw compressors McQuay ALS WHS Digital inputs Only Chiller unit MACHINE TYPE 0 UNIT 1 Master UNIT 2 Slave n 1 UNIT 3 Slave n 2 UNIT 4 Slave n 3 On Off by Main S witch On Off by Main S witch On Off by Main S witch On Off by Main S witch Evaporator flow controller enab
35. sted to start and it will work as described while the first one will keep working in steady configuration in theory at 10096 If temperature remains over point E step by step all compressors will follow in the same way e On temperature decrease Assume all compressors working and at full capacity When outlet temperature falls down to the zone of floating increase since compressors are at full capacity further power increase is impossible If temperature keeps falling down it wil reach the neutral zone where compressors will maintain a stable working Falling down again it will reach the zone of floating decrease Here starts floating in decrease the first or the last compressor started based on the rotation Decrease phase will continue for a time selectable until we can consider compressor at zero capacity next it will be shut down and a phase of decrease will start for a new compressor If temperature will remain in that zone all compressors will be shut down in the same way e Special Cases a Assume the temperature is over the point E and one compressor is in phase of increase If temperature falls down to the zone of floating increase the compressor still not arrived at full capacity will continue increasing its power with a duration of pulses now variable instead of fixed If temperature continues falling down it will arrive to the neutral zone where all compressors will work in steady mode next to the zone of floating decrease wher
36. t each 1 0 card and each terminal has been given the correct address during the network design It is important to remember that the address being set up through the dipswitches is received only if a reset of the device is carried out Furthermore you should to carry out a global resetting of all the network devices if you realise that you have chosen the wrong configuration of the addresses several cards with the same address The configuration procedure has to be activated for each I O card and must involve all the network terminals Such procedure can be activated from any terminal which can also have been timerarily connected only to carry out the configuration operations and removed when finished The operations to be done are the following Step 1 1 0 card selection The procedure is activated by pressing simultaneously the 0 1 2 buttons for atleast 5 sec for compatibility also the 4 Enter buttons carry outthe same function On Off Alarm If the display is of the LCD type the following mask is displayed Terminal Adr nn I O Board Adr 12 The Terminal Adr field fixed and represents the address of the terminal on which you are operating set up through the posterior dipswitch The 1 0 Board Adr field at first displays the address of the MicroTech II card actually connected to the terminal If the terminal is not connected to any MicroTech card the characters are shown Through the arrow buttons it is possible to modif
37. verified after 120 sec the controller will shut down 1 compressor in alarm of low pressure if after this the pressure will remain lower than zero after further 120 seconds it will stop in alarm also the second compressor The time of delay will be only 40 seconds if low pressure is equivalent to 10 C 2 High condenser pressure During that control it can happen that excessive refrigerant fill the condenser dramatically reducing the exchange surface In that condition condenser pressure could increase over the maximum allowed If so controller will unload following the logic of the pressure of condensation 3 High discharge superheat Closing the expansion valve saturated suction temperature will reduce and of course suction superheat will increase As a reaction also discharge superheat will increase If during the WPC discharge temperature should reach the selected value of 85 C selectable value the controller will active a procedure for cooling oil by enabling the output for the liquid injection solenoid If Release 1 0 01 05 01 page 20 20 Service Manual Preliminary Version nelle aA MicroTech II Control discharge temperature will keep in going up controller will stop at 95 C in alarm the corresponding compressor If otherwise temperature will go down the controller will disable the liquid injection when that temperature will be lower than the setpoint minus the selected differential On working It can happen t
38. visor Slave function Management of a refrigeration circuit start stop alarms EXV for each card Common functions Both master and slave manage configuration and regulation max 2 EVD drivers and consequently max 2 EXV valve each Regulation probe The thermo regulation probe have to be connected only to the master MicroTech Il Thermoregulation of the whole system Terminal LCD 4x20 Each MicroTech Il card driver card and terminal are identified with an address The terminal address is selected via the dip switches situated on the back of the terminals themselves whereas the address he 1 0 cards is always selected via dipswitches placed on a card with MICROTECH IIADR 0000 code without clock option or MICROTECH IICLKMEMO with clock option this card has to be inserted in the clock plug in connector The address dip switches ofthe EVD driver are on the back of the front cover removable of the driver itself The master MicroTech Il must have address 1 The MicroTech II slave must have address 2 The driver 1 must have address 3 The driver 2 must have address 4 The driver 3 must have address 5 The driver 4 must have address 6 The local terminal must have address 8 Note when the unitis ON all the MicroTech II cards and the drivers must be ON LED On Off on the terminal ON for all the units e The master unit starts stops all the units e The slave unit starts stops itself only If the slave uniti
39. y such selection in order to force the connection to another controller The values displayed during the selection are the addresses of the MicroTech Il cards actually being connected to network If no MicroTech the moment is active itis not possible to change the display By pressing the Enter button you get out of the first phase of the procedure which resides in the terminal and you enter the real terminal configuration mask see step 2 If the terminal remains inactive no button pressed for more than 15 seconds it automatically leaves the configuration procedure Step 2 selection of the associated terminals For LCD displays the displayed masks are Terminal Config Press ENTER to continue No In this mask the Enter button moves the cursor from one field to another whereas the arrow buttons change the current value of the field The P 12 symbol this case indicates that the 1 0 address 12 card has been selected Release 1 0 01 05 01 page 29 29 Service Manual Preliminary Version MeQuay EA MicroTech II Control e leave the configuration procedure and store select the field and with the cursor buttons until Y es appears and then press Enter To get out without storing it is necessary to wait for 30 sec without pressing any button Display of the terminal connection state e terminal shows the state of inactivity of the CPU card of which it is displaying the output clears com
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