MCC 68AC353-102 MICROMAX Operation And Service Download Page 19

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1--10

2012 Mobile Climate Control

T-348 Rev. 07/2012

1.9 AIR FLOW

The paths for ambient air through the condenser and

coach air through the evaporator are illustrated in

Figure 1-5.

EVAPORATOR

FRESH AIR

HEATER COIL

EVAPORATOR COIL

From Ambient

Through Condenser

Through Fan

Return To Ambient

Through Condenser

CONDENSER

From Ambient

COIL RETURN

AIR FILTERS

Through Fan

COACH RETURN

AIR FILTER

Figure 1-5 System Air Flow

Summary of Contents for 68AC353-102 MICROMAX

Page 1: ...OPERATION AND SERVICE for 68AC353 102 MICROMAX REV 07 2012 T 348 Manual T 348 2012 Mobile Climate Control...

Page 2: ...ssembly 1 4 1 4 2 Discharge Check Valve 1 4 1 4 3 Rooftop Unit 1 5 1 4 4 Condensing Section 1 6 1 4 5 Evaporator Section 1 7 1 4 6 Fresh Air System 1 7 1 4 7 System Operating Controls And Components 1...

Page 3: ...Alarm Description 2 4 2 3 12 Hour Meters 2 4 2 4 MICROPROCESSOR DIAGNOSTICS 2 4 2 4 1 Control 2 5 2 4 2 Diagnostic Mode 2 5 2 4 3 System Parameters 2 5 2 4 4 Test Mode 2 6 TROUBLESHOOTING 3 1 3 1 SEL...

Page 4: ...ING REFRIGERANT TO SYSTEM 4 8 4 8 1 Checking Refrigerant Charge 4 8 4 8 2 Adding Full Charge 4 9 4 8 3 Adding Partial Charge 4 9 4 9 CHECKING FOR NONCONDENSIBLES 4 9 4 10 CHECKING AND REPLACING HIGH O...

Page 5: ...Data Communications 1 20 Figure 1 14 Micromate Control Panel 1 21 Figure 2 1 Capacity Control Diagram 2 2 Figure 4 1 Opening Top Cover Evaporator 4 2 Figure 4 2 Condenser Cover Removal 4 2 Figure 4 3...

Page 6: ...Brushless Motors 68AC353 102 2 102 7 5 11 Figure 5 11 Wiring Schematic Control Board Power Circuit Brushless Motors 68AC353 102 2 102 7 5 12 Figure 5 12 Wiring Schematic Condenser Motor Power Circuit...

Page 7: ...nit cover before turning power off Be sure power is turned off before working on motors controllers solenoid valves and electrical controls Tag circuit breaker and power supply to prevent accidental e...

Page 8: ...oach on a level surface with park ing brake applied Turn main electrical disconnect switch to the off position WARNING Do not use a nitrogen cylinder without a pressure regulator WARNING Do not use ox...

Page 9: ...To prevent trapping liquid refrigerant in the manifold gauge set be sure set is brought to suc tion pressure before disconnecting CAUTION Use care when checking manipulating wires plugs attached to t...

Page 10: ...arious options may be factory or field equipped to the base unit These options are listed in the tables and described in the following subparagraphs 1 3 1 Condenser Cover Skins The condenser section m...

Page 11: ...th a fresh air exchange assembly or an air exchange blank off plate Fresh air exchange assemblies may be of the 25 or 50 opening 1 3 11 Controller Kit The Micromax Controller operates the system throu...

Page 12: ...3 Left ORS With Out Front Box Connection Evaporator Connection Kit Indash 1 Right 2 Left Air Exchange Kit 1 0 to 50 2 None 3 0 to 25 Controller Kit 1 Micromax With GR60 Relay Board right 2 Micromax Re...

Page 13: ...ressure and temperature of the refrigerant and forces it into the condenser tubes The clutch assembly provides a means of belt driving the compressor by the bus engine The suction and discharge servic...

Page 14: ...vaporator section Micromax electronics and the Fresh Air System All components are accessible by lifting the condenser and evaporator top covers Descriptions of the systems are provided in the followi...

Page 15: ...rigerant circulating inside the tubes this results in condensation of the refrigerant into a liquid The receiver collects and stores liquid refrigerant The receiver is also fitted with a fusible plug...

Page 16: ...valve in the evaporator assembly Service valves enable isolation of the filter drier for service The thermostatic expansion valve meters flow of refrigerant entering the evaporator coils The liquid l...

Page 17: ...ystem may operate in the clutch cycle or reheat mode A controller programmed for clutch cycle will de energize the compressor clutch and allow the system to operate in the vent mode until further cool...

Page 18: ...pressure drop to shut down the system when a low pressure condition occurs In addition if the microprocessor monitors a pressure less than 10 psig 0 68 bar by the suction pressure transducer mounted i...

Page 19: ...r through the evaporator are illustrated in Figure 1 5 EVAPORATOR FRESH AIR HEATER COIL HEATER COIL EVAPORATOR COIL EVAPORATOR COIL From Ambient Through Condenser Through Fan Return To Ambient Through...

Page 20: ...bserve refrigerant charge level The refrigerant leaves the receiver and passes through the charge isolation valve to the liquid line solenoid valve From the liquid line solenoid valve the refrigerant...

Page 21: ...e Valve Port 9 Dash Air Suction Tee Option 10 Suction Pressure Transducer 11 Evaporator Coil 12 Thermal Expansion Valve TXV 13 TXV Bulb 14 TXV Equalizer Line 15 Liquid Line Solenoid Valve 16 Filter Dr...

Page 22: ...the heat valve during the heating and reheat modes to maintain required temperaturesinside thebus Enginecoolant is circulated through the heating circuit by the engine and an auxiliary boost water pum...

Page 23: ...mate Control T 348 Rev 07 2012 1 12 CONTROL PANEL WITH GR60 RELAY BOARD 1 5 4 3 2 1 Logic Board See Figure 1 10 2 Relay Board GR60 See Figure 1 11 3 Power Relay ON 4 Fresh Air 5 Terminal Block TB Figu...

Page 24: ...With CAN With Out CAN 9 2 1 3 4 5 8 7 6 1 Logic Board See Figure 1 10 2 Relay Board See Figure 1 12 3 Logic Board Data Communications See Figure 1 13 4 Power Relay ON 5 Fuses 6 Fresh Air 7 Power Term...

Page 25: ...J4 Interlock Inputs WTS low side pressure switch etc J5 Relay board interface J6 Sensor inputs Thermistors etc J7 Diagnostics interface RS232 DB9 J8 Not used D2 Blinks once per second in normal operat...

Page 26: ...high speed not energized in low speed K11 Connects the negative side of condenser fans 1 2 to ground in high speed Connects the negative side of condenser fans 1 2 to the positive side of condenser f...

Page 27: ...essure switch JP5 Spare output fresh air output heat valve JP6 Unloaders 1 2 g LEDS D 2 Relay K1 output active evaporator fans 1 2 3 4 energized D 6 Will be brightly lit if evaporator fans 1 2 3 4 are...

Page 28: ...Relay Board c Fuses F1 Fresh air relay F2 Unloader 1 relay F3 Evaporator fan motor relay F4 Fault light out relay F5 Unloader 2 relay F6 Heater relay F7 Clutch relay F8 Spare F9 Condenser motor fan re...

Page 29: ...2 Optional 4 Alt CAN_L CAN Port 2 Optional 5 N C 6 N C 7 N C 8 LED Gnd Status Indicator Optional 9 CAN_H J1939 Port 10 CAN_L J1939 Port 11 N C 12 N C Pin Function Remarks 13 RS 232 TXD HVAC Data Port...

Page 30: ...9 10 11 1 Display 2 DOWN Button decrease selection 3 UP Button increase selection 4 VENT Only Button 5 AUTO Button Automatic Control 6 COOLING Only Button 7 HEAT Only Button 8 FAN SPEED Button 9 FRES...

Page 31: ...desired press the corresponding button refer to Figure 1 14 to illuminate the indicator light and place the system in that mode of operation 4 If low or high speed evaporator fan speed is de sired pre...

Page 32: ...al cycles 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 the...

Page 33: ...er Control When operating in cooling the unloaders are used to reduce system capacity as return air temperature approaches set point Operation of the unloaders balances system capacity with the load a...

Page 34: ...a high pressure alarm has been activated and operation has not been locked out refer to Table 3 2 2 3 9 Compressor Clutch Control A belt driven electric clutch is employed to transmit engine power to...

Page 35: ...nnected NOTE When modifying the setpoint temperature for diagnostic purposes be sure to reset the setpoint when testing is complete 2 4 2 Diagnostic Mode The diagnostic mode can be entered by pressing...

Page 36: ...ion will be T00 This indicates the controller is in the test mode and all relays are de energized Press the DOWN arrow key to bring the Micromate to the next test screen and energize the corresponding...

Page 37: ...ator fan speed will be set to low This value can be modified between 0 and 10 degrees F The default value is 1 degree F P12 Heat Control Window This is the number of degrees F below setpoint before th...

Page 38: ...freeze alarm will be activated The default value is 32 F This value can be modified between 20 F and 40 F in one degree increments by using the arrow keys P29 Relay Module Voltage This is the voltage...

Page 39: ...n the value is ON alarms A33 and A34 will be displayed P41 Fresh Air Damper When the value is OFF the fresh air damper will operate 5 F above or below the control set point When the value is ON the fr...

Page 40: ...fter a slight pause the second set of flashes is the second digit The Micromate control panel display will indicate alarms with the code A or i where A is an active alarm prefix i is an inactive alarm...

Page 41: ...unit 5 Launch HyperTerminal software by clicking on start All Programs accessories communications Hy perTerminal 6 With the Caps Lock set press the S and 5 keys in unison then press Enter 7 With the...

Page 42: ...voltage or wiring Re place sensor or repair wiring Both unloaders are ener gized A16 Discharge Pressure Transducer Failure Discharge pressure trans ducer failure or wiring defective Ensure all connect...

Page 43: ...A25 Not used A26 Not used A31 Maintenance Alarm 1 The compressor hour meter is greater than the value in Maintenance Hour Meter 1 Reset the maintenance hour meter Alarm will be generated A32 Maintenan...

Page 44: ...eating system Reheat coolant valve stuck open 3 3 9 3 3 4 Abnormal Pressures High discharge pressure Discharge transducer failure Refrigerant overcharge Noncondensable in system Condenser motor failur...

Page 45: ...rost Check Replace 1 8 Check 3 3 8 Expansion Valve Malfunction Low suction pressure with high super heat Low refrigerant charge Wax oil or dirt plugging valve orifice Ice formation at valve seat Power...

Page 46: ...refrig erant When working with refrigerants you must comply with all local government environmental laws 4 1 MAINTENANCE SCHEDULE SYSTEM SYSTEM REFERENCE SECTION ON OFF a Daily Maintenance X X Pre tri...

Page 47: ...ator motor assemblies d Lift end of metal rod prop and place in plate on cover assembly 1 4 Turn Cam Lock 5 Places each side Hinge Plate Figure 4 1 Opening Top Cover Evaporator 4 3 REMOVING TOP COVER...

Page 48: ...gauge hose set do the following a Preparing Manifold Gauge Hose Set For Use 1 If the manifold gauge hose set is new or was exposed to the atmosphere it will need to be eva cuated to removecontaminant...

Page 49: ...ssure switch 8 c Start the system and run in cooling Stop the unit when suction reaches 2 psig 0 14 Bar d Frontseat the compressor suction service valve 6 to traprefrigerant inthe highside ofthe syste...

Page 50: ...f manifold gauge set Evacuate compressor to 500 microns Close off vacuum pump isolation valve 15 and vacuum gauge isolation valve 14 and stop pump Wait 5 minutes to verify that vacu um holds e Once va...

Page 51: ...6 Service Port Suction Service Valve 7 Suction Pressure Transducer 8 Low Pressure Switch to crankcase 9 Dash Air Liquid Tee Optional 10 Dash Air Suction Tee Optional 11 Charge Isolation Valve 12 Therm...

Page 52: ...4 Removing Entire System Charge To remove the entire refrigerant charge do the following a Connect a manifold gauge set to the system as shown in Figure 4 6 b Connect a reclaimer to the center manifo...

Page 53: ...open vacuum gauge valve items 22 23 e Evacuate unit until vacuum gauge indicates 500 microns Hg vacuum f Close off pump valve 23 and stop pump Wait five minutes to see if vacuum holds g Remove externa...

Page 54: ...g charging hose from container to center connec tion on gauge manifold Purge air from hoses c Run the unit in the cool mode as described in sec tion 4 8 1 With the suction service valve mid seated ope...

Page 55: ...for a restriction by feeling the inlet and outlet lines of the filter drier If the outlet side feels cooler than the inlet side then the filter drier should be changed 1 5 4 3 2 3 1 Filter Drier Inle...

Page 56: ...e the refrigerantcharge from the system b Place main battery disconnect switch in OFF posi tion and lock c Disconnect wire leads to coil d Remove coil locking nut and O Ring then the threaded collar e...

Page 57: ...the valve assembly into the unit again taking care to oil and install new O Rings h Fasten equalizer line to the expansion valve i Leak check the new valve and evacuate and dehy drate low side Refer t...

Page 58: ...il To removethe filters do the following a Place main battery disconnect switch in OFF posi tion and lock b Open the evaporator top cover Refer to para graph 4 2 c Grasp and lift the filter elements o...

Page 59: ...after checking switch op eration Refer to paragraph 4 10 i Remove clutch assemble and retain original clutch key Install on replacement compressor j Install compressor in unit by performing the re mov...

Page 60: ...stall spacer nuts and tighten to 7 8 ft lbs 1 0 to 1 1 mkg l Reconnect wiring and test clutch operation 4 15 3 Shim less Compressor Clutch As of February 4 2008 all 05G and 05K compressor clutches sup...

Page 61: ...vel is brought to the proper level 3 Evacuate the compressor to 500 microns Back seat the compressor service valves and repeat the oil level check procedure f To add oil to the compressor do the follo...

Page 62: ...heck transduc ers a With the system running use the driver display and manifold gauges to check suction and or dis charge pressure s simultaneously b Determine with the gauges whether one or both pres...

Page 63: ...ed Table 4 2 Pressure Transducer Voltage hg Voltage Psig Voltage Psig Voltage Psig Voltage Psig Voltage Psig Voltage 20 0 369 40 0 858 95 1 397 150 1 936 205 2 475 260 3 014 10 0 417 45 0 907 100 1 44...

Page 64: ...uration is removed transducers will assume to be present F Refrigerant R 22 R 134a When the refrigerant configuration is removed the refrigerant is set for R 22 The default refrigerant is R 134a G Uni...

Page 65: ...8 1 11 1 09 18 8 17 1 1 20 1 18 20 7 18 5 1 30 1 28 22 6 19 9 1 40 1 37 24 4 21 4 1 50 1 48 26 3 22 9 1 61 1 58 Temperature Pressure F C Psig Kg cm Bar 28 2 24 5 1 72 1 69 30 1 26 1 1 84 1 80 32 0 27...

Page 66: ...a Micromate control panel as the operators control there is no wiring to the Logic Board J3 connector instead the Micromate control panel is hard wired to the Logic Board connector J2 When the microm...

Page 67: ...5 2 2012 Mobile Climate Control T 348 Rev 07 2012 98 63069 Figure 5 1 Wiring Schematic Legend PM Motors 68AC353 102 102 4 102 5...

Page 68: ...5 3 2012 Mobile Climate Control T 348 Rev 07 2012 98 63069 Figure 5 2 Wiring Schematic Control Circuit PM Motors 68AC353 102 102 4 102 5...

Page 69: ...5 4 2012 Mobile Climate Control T 348 Rev 07 2012 98 63069 Figure 5 3 Wiring Schematic Power Circuit PM Motors 68AC353 102 102 4 102 5...

Page 70: ...5 5 2012 Mobile Climate Control T 348 Rev 07 2012 98 63098 Figure 5 4 Wiring Schematic Legend Brushless Motors CAN 68AC353 102 1 102 3 102 6...

Page 71: ...5 6 2012 Mobile Climate Control T 348 Rev 07 2012 98 63098 Figure 5 5 Wiring Schematic Control Circuit Brushless Motors CAN 68AC353 102 1 102 3 102 6...

Page 72: ...5 7 2012 Mobile Climate Control T 348 Rev 07 2012 98 63098 Figure 5 6 Wiring Schematic Power Circuit Brushless Motors CAN 68AC353 102 1 102 3 102 6...

Page 73: ...5 8 2012 Mobile Climate Control T 348 Rev 07 2012 98 63098 Figure 5 7 Wiring Schematic Condenser Circuit Brushless Motors CAN 68AC353 102 1 102 3 102 6...

Page 74: ...5 9 2012 Mobile Climate Control T 348 Rev 07 2012 98 63098 Figure 5 8 Wiring Schematic Evaporator Circuit Brushless Motors CAN 68AC353 102 1 102 3 102 6...

Page 75: ...5 10 2012 Mobile Climate Control T 348 Rev 07 2012 98 63116 Figure 5 9 Wiring Schematic Legend Brushless Motors 68AC353 102 2 102 7...

Page 76: ...5 11 2012 Mobile Climate Control T 348 Rev 07 2012 98 63116 Figure 5 10 Wiring Schematic Control Circuit Brushless Motors 68AC353 102 2 102 7...

Page 77: ...5 12 2012 Mobile Climate Control T 348 Rev 07 2012 98 63116 Figure 5 11 Wiring Schematic Control Board Power Circuit Brushless Motors 68AC353 102 2 102 7...

Page 78: ...5 13 2012 Mobile Climate Control T 348 Rev 07 2012 98 63116 Figure 5 12 Wiring Schematic Condenser Motor Power Circuit Brushless Motors 68AC353 102 2 102 7...

Page 79: ...5 14 2012 Mobile Climate Control T 348 Rev 07 2012 98 63116 Figure 5 13 Wiring Schematic Evaporator Motor Power Circuit Brushless Motors 68AC353 102 2 102 7...

Page 80: ...2 5 Discharge Check Valve 1 4 Discharge Pressure 2 4 E Evacuation 4 8 Evacuation One Time 4 8 Evacuation Triple 4 8 Evaporator Fan 1 8 2 4 Evaporator Section 1 7 Exit Alarm Queue 3 2 F Filter Drier 4...

Page 81: ...GR60 1 17 1 18 Rooftop Unit 1 5 S SAFETY DEVICES 1 9 Self Diagnostics 3 1 SERVICE 4 1 Service Valves 4 3 Suction Pressure 2 3 Superheat 4 12 System Parameters 2 5 System Shutdown 2 1 System Start up...

Page 82: ...onal performance in mobile climate comfort Every driver deserves the best possible vehicle climate with MCC products www mcc hvac com Member of MCC Group S Certified ISO 9001 and ISO 1 4001 Specificat...

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