Carrier 68RF50 Neoplan-LA Operation And Service Manual Download

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T-271

Bus Air
Conditioning
Unit

Model
68RF50
NEOPLAN-LA

Summary of Contents for 68RF50 Neoplan-LA

Page 1: ...T 271 Bus Air Conditioning Unit Model 68RF50 NEOPLAN LA...

Page 2: ...ATION AND SERVICE MANUAL Carrier Transicold Division Carrier Corporation P O Box 4805 Syracuse N Y 13221 Carrier Corporation 1996 D Printed in U S A 0496 BUS AIR CONDITIONING UNIT MODEL 68RF50 NEOPLAN...

Page 3: ...2 Unit Runs But has Insufficient Cooling 3 1 3 3 Abnormal Pressure 3 1 3 4 Abnormal Noise and Vibrations 3 2 3 4 1 Abnormal Noise 3 2 3 4 2 Abnormal Vibration 3 2 3 5 Temperature Controller Malfunctio...

Page 4: ...e During Cooling with Reheat Mode 2 2 2 3 Temperature Controller Sequence During Heating Mode 2 3 2 4 Cooling Cycle High Speed Vent Mode Operation 2 4 2 5 High Speed Unloaded 2 cylinder operation Cool...

Page 5: ...iii iv LIST OF TABLES Table Page 1 1 Model Chart 1 1 1 2 Additional Support Manuals 1 1 1 3 Safety Devices 1 6 4 1 Pressure Switch Continuity Check 4 7 4 2 R 134a Temperature Pressure Chart 4 14...

Page 6: ...olled automatically by the temperature controller which maintains the vehicles interior temperature at the desired setpoint The units are equipped with a reheat cycling clutch switch to give the opera...

Page 7: ...Evaporator Blower 6 Evaporator Blower Motor 7 Evaporator Blower 8 Heater Coil 9 Evaporator Coil 10 Sight Glass 11 Return Air Opening 12 Evaporator Coil 13 Heater Coil 14 Evaporator Blower 15 Evaporat...

Page 8: ...nser Fan and Motor 5 Discharge Line Valve 6 Discharge Check Valve 7 Ambient Air Switch 8 Filter Drier Outlet Valve 9 Filter Drier 10 Receiver Outlet or Filter Drier Inlet Valve 11 Sight Glass Figure 1...

Page 9: ...RCS1 21 Circuit Breaker CB3 40 Amp 22 Circuit Breaker CB2 40 Amp 23 Circuit Breaker CB1 15 Amp 24 Evaporator Fan Relay 1 EFR1 25 Power Terminal Block PTB 26 Resistor 1 Evaporator RES1 27 Run Control S...

Page 10: ..._F 14 4_ C to 16_F 8 9_C at 40_F 4 4_C evap temp MOP Setting 53 9 4 psig 3 8 0 28 kg cm d Low Pressure Switch LPS R 134a Unit Opens at 10 3 psig 0 70 0 21 kg cm Closes at 25 3 psig 1 8 0 21 kg cm e Hi...

Page 11: ...ll circuit breakers when opened must be manually reset by depressing the breaker button When the High Pressure Switch HPS or Low Pressure Switch LPS opens and unit operation stops place the driver s A...

Page 12: ...TerminalBlock TC for operation of the control system for heating cooling or cooling with reheat modes of operation c Thermal Switches Low Ambient Thermostat LATH TheLowAmbient Thermostat LATH monitor...

Page 13: ...izing relay HR2 closes a set of normally closed HR2 contacts to activate the heating control circuit enabling the system to provide heating during the cooling with reheat mode Evaporator Fan Relay 1 E...

Page 14: ...OID VALVE The Liquid Line Solenoid Valve LLS is located in the evaporator section of the unit on the roof of the bus SeeFigure 1 1 Theelectricallyoperated solenoidvalve is energized when the Clutch Re...

Page 15: ...ceiver The receiver serves as a liquid refrigerant reservoir so a constant supply of liquid is available to the evaporator as needed and as a storage space when pumping down the system The receiver is...

Page 16: ...set of normally open ACR1 contacts to activate the cooling control circuit components Voltage is also applied to the Run Control Switches RCS1 and RCS2 With these switches in the ON position voltage i...

Page 17: ...ior temperature falls to 1 F below the thermostat setpoint and the Reheat Cycle Switch RHCS is set to the REHEAT position the thermostat switches from cooling only operation to cooling with reheat See...

Page 18: ...ge Cutout Relay senses circuit control voltage and de energizes to open normally open LVCO contacts to de energize the Clutch Relay CR during cooling when a low voltage condition occurs When the vehic...

Page 19: ...2 4 Figure 2 4 Cooling Cycle High Speed Vent Mode Operation Energized Circuit De energized Circuit...

Page 20: ...2 5 Figure 2 5 High Speed Unloaded 2 cylinder operation Cool Mode Operation Energized Circuit De energized Circuit...

Page 21: ...2 6 Figure 2 6 High Speed Semi Loaded 4 cylinder operation Cool Mode Operation Energized Circuit De energized Circuit...

Page 22: ...2 7 Figure 2 7 High Speed Fully Loaded 6 cylinder operation Cool Mode Operation Energized Circuit De energized Circuit...

Page 23: ...2 8 Figure 2 8 High Speed Unloaded 2 cylinder operation Cool with Reheat Mode Operation Energized Circuit De energized Circuit...

Page 24: ...2 9 2 10 Figure 2 9 Heating Cycle Low Speed Heat Mode Operation Energized Circuit De energized Circuit...

Page 25: ...SUFFICIENT COOLING Compressor Compressor valves defective See Note V belt loose Check Refrigeration system Abnormal pressures 3 4 No or restricted evaporator air flow 2 3 Expansion valve malfunction 3...

Page 26: ...See Note tend to equalize when unit is operating 3 4 ABNORMAL NOISE AND VIBRATIONS 3 4 1 ABNORMAL NOISE Compressor Loose mounting bolts Check Tighten Worn bearings See Note Worn or broken valves See N...

Page 27: ...ken capillary 4 12 Loose bulb Check Tighten Low superheat and liquid Superheat setting too low 4 12 slugging in compressor Ice holding valve open 4 7 4 12 Foreign material in valve 4 7 4 12 Pin and se...

Page 28: ...r and refrigerant lines Turning the valve stem counterclockwise all the way out will backseat the valve to open the suction or discharge line to the compressor and close off the gauge connection In no...

Page 29: ...4 SYSTEM PUMPDOWN To service or replace the filter drier expansion valve evaporator coil or suction line pump the system refrigerant into condenser coil and receiver tank as follows a Attach the gauge...

Page 30: ...refrigerant charge systemwith refrigerant to build up pressure between 30 to 50 psig 2 1 to 3 5 kg cm NOTES 1 It is recommended that the appropriate refrigerant used be used to pressurize the system...

Page 31: ...rant removal and evacuation leak test unit 2 Remove all remaining refrigerant charge in the system 3 Connect evacuation manifold vacuum pump vacuum gauge reclaimer and hoses as shown in Figure 4 4 All...

Page 32: ...g the system The correct charge is 16 lbs 6 When refrigerant cylinder weight scale indicates that the correct charge has been added close liquid line valve at the cylinder and backseat the filter drie...

Page 33: ...are nut using two open end wrenches i Open the filter drier inletvalve slowlyto purgethe filter drier momentarily Tighten the outlet flare nut using two open end wrenches j Immediately backseat fully...

Page 34: ...line from expansion valve 5 Remove flange screws and lift off power head and cage assemblies Check for foreign material in valve body 6 Install new gaskets and assemble new cage and power head assemb...

Page 35: ...c Drain coil by removing enough coolant from vehicle cooling system d Disconnect water line from the coil CAUTION If unit was recently operating be careful of remaining hot coolant in the hoses when d...

Page 36: ...material in the valve a To replace a burnout coil it is not necessary to drain the coolant from the system 1 Place the run control switch in the OFF position 2 Disconnect wire leads to coil 3 Remove c...

Page 37: ...l it is notnecessary toremove the refrigerant charge from the system 1 Place the run control switch in the OFF position 2 Disconnect wire leads to coil 3 Remove coil retaining clip and nameplate 4 Lif...

Page 38: ...pening inside the bus The filters should be checked for cleanliness periodically depending on operating conditions A dirty air filter will restrict the air flow over the evaporator coil This could cau...

Page 39: ...of liquid refrigerant Correct this situation before adding oil c Check the level of the oil in the sight glass with the compressor operating The correct level should be between 1 4 and 1 2 of the sigh...

Page 40: ...id 10 Discharge Service Valve Figure 4 12 Compressor Model O5G a To Remove Oil From the Compressor 1 If the oil level recorded in paragraph 4 20 2 is above 1 2 of the sight glass remove oil from the c...

Page 41: ...65 18 64 1 4 51 4 42 6 21 3 7 0 26 0 26 70 21 71 1 5 00 4 90 4 20 4 6 0 32 0 32 75 24 78 7 5 53 5 43 2 19 5 6 0 39 0 39 80 27 86 7 6 10 5 98 0 18 6 5 0 46 0 45 85 29 95 3 6 70 6 57 2 17 7 6 0 53 0 52...

Page 42: ...5 1 SECTION 5 ELECTRICAL 5 1 INTRODUCTION This section includes electrical wiring schematics for model 68RF50 for NEOPLAN LA The schematic shown in this section is for R 134a refrigerant systems...

Page 43: ...5 2 Figure 5 1 Electrical Wiring Schematic Diagram 68RF50 with Rotron Brushless Motors Dwg No C 070 935 Rev C Sheet 1 of 2...

Page 44: ...5 3 5 4 Figure 5 1 Electrical Wiring Schematic Diagram 68RF50 with Rotron BrushlessMotors Dwg No C 070 935 Rev C Sheet 2 of 2...

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