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4-13

T-288

Figure 4-11. Model 05G Compressor

b. Installing

NOTE

It is important to check the compressor oil
level of the new compressor.

1. The

original

unloader

valves

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 cap
screw into top of piston. A small Teflon seat ring
at bottom of piston must be removed.

NOTE

The service replacement compressor is
sold without shutoff valves (but with valve
pads). These should be placed on the old
compressor before shipping. Check oil
level in service replacement compressor. If
none add the applicable amount outlined in
section 1.2.b.

2. Remove the high pressure switch and install

on new compressor after checking switch
setting (refer to section 4.11).

3. Install compressor in unit by reversing step

4.18.a. It is recommended using new locknuts
when

replacing

compressor.

Install

new

gaskets on service valves and tighten bolts
uniformly.

4. Attach two lines to the suction and discharge

service valves.

Dehydrate

and evacuate

compressor to 500 microns (29.90” Hg
vacuum = 75.9 cm Hg vacuum). Turn off valves
on both lines to pump.

5. Fully backseat (open) both suction and

discharge service valves.

6. Remove vacuum pump lines and install

manifold gauges.

7. Start unit and check for noncondensibles

8. Check refrigerant level and add if necessary.

9. Check compressor oil level. (Refer to section

4.18.2.) Add oil if necessary.

10. Check compressor unloader operation.

11. Check refrigerant cycles.

4.18.2 Checking the Compressor Oil Level

NOTE

It may be necessary to preheat the coach
and/or operate the system in the Reheat
Mode to keep the compressor fully loaded
throughout this procedure.

a. Operate the coach for at least one-half hour at

fast idle engine speed with the temperature
controls at coolest setting and the compressor
fully loaded (six cylinder operation).

b. Ensure the system is fully charged, as

indicated in section 4.9, and the compressor
crankcase is warm to the touch after fifteen
minutes of operation.

NOTE

If the compressor is not level, an average
between both sight glasses will have to be
made to determine proper oil level.

c. Shut off the A/C system and immediately

record the oil level in the compressor oil level
sight glass(es). The correct level should be
between the “Min” and “Max” marks

on

compressor crankcase adjacent to the sight
glasses. If the oil level is below the “Min” mark,
add oil to the compressor, as outlined in the
following section. If the oil level is above the
“Max” mark, remove oil. If proper oil level is
obtained, the coach can be released into
service.

4.18.3 Adding Oil to the Installed Compressor

CAUTION

The appropriate compressor oil must be
used according to the refrigerant used in the
system. (Refer to section 1.2.b.)

There are three methods of adding oil to the
compressor , as outlined in the procedures that
follow. The oil sump method, paragraph a., is the
preferred method.

a. Oil Sump Method

1. With the system off, connect manifold gauge

set to the compressor service valves. Connect
the blue hose to the suction port and red hose
to the discharge port. (See Figure 4-2.)

2. Frontseat (clockwise) the compressor suction

and discharge service valves.

3. Reclaim the refrigerant in the compressor.

Shut off the reclaimer

and verify that

the

Summary of Contents for Carrier TRANSICOLD 68RM35-604-20

Page 1: ...T 288 Rearmount 68RM35 604 20 R 134a NYCDOT...

Page 2: ...MANUAL OPERATION AND BUS AIR CONDITIONING UNIT Rearmount 68RM35 604 20 R 134a Carrier Transicold Division Carrier Corporation P O Box 4805 Syracuse N Y 13221 Carrier Corporation 1999 D Printed in U S...

Page 3: ...r 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...

Page 4: ...rosive and toxic compounds WARNING Be sure to avoid refrigerant coming in contact with the eyes Should refrigerant come in contact with the eyes wash eyes for minimum of 15 minutes with potable water...

Page 5: ...1 3 TROUBLESHOOTING 3 1 3 1 UNIT WILL NOT COOL 3 1 3 2 SYSTEM RUNS BUT HAS INSUFFICIENT COOLING 3 1 3 3 ABNORMAL PRESSURES 3 1 3 4 ABNORMAL NOISES OR VIBRATIONS 3 2 3 5 TEMPERATURE CONTROLLER MALFUNC...

Page 6: ...r 4 13 4 18 5 Removing Oil from the Compressor 4 13 5 ELECTRICAL SCHEMATIC WIRING DIAGRAM 5 1 5 1 INTRODUCTION 5 1 LIST OF ILLUSTRATIONS Figure Page 1 1 Unit Assembly Back View 1 2 1 2 Unit Assembly I...

Page 7: ...l 05G Compressor 4 12 4 12 Compressor Oil Charge Connections 4 13 5 1 Electrical Schematic Diagram Legend and Symbols 5 2 5 2 Electrical Schematic Diagram 5 3 LIST OF TABLES Table Page 1 1 Model Chart...

Page 8: ...of the bus These units interface with the bus driver switches and pump to provide a complete air conditioning system All control systems are powered by 24 vdc supplied by the bus battery and alternato...

Page 9: ...11 Discharge Line Isolation Valve 12 Receiver Sight Glass Upper 13 Moisture Liquid Indicator 14 Unloader Pressure Switch UPS3 Upper 15 Condenser Fan Switch CFS Lower 16 Evaporator Fan Housing Curbsid...

Page 10: ...CS 1 Electrical Control Panel See Figure 1 3 2 Liquid Line Solenoid Valve 3 Thermostatic Expansion Valve TXV 4 Roadside Blower Housing 5 Air Filter 6 Evaporator Coil 7 Curbside Blower Housing 1 CDR 6...

Page 11: ...14 Cool Disable Relay CDR 15 Evaporator Speed Relay ESR 16 Power Terminal Block PTB 17 Return Air Probe 18 Air Conditioning Stop Relay No 2 ACSR2 19 Heat Relay HR 20 Air Conditioning Stop Relay No 1...

Page 12: ...k 05G Compressor Electric Unloader Pressure Switches UPS1 UPS2 UPS3 See Table 1 2 for settings 1 3 ELECTRICAL SPECIFICATIONS a Evaporator Blower Motor Bearing Lubrication Factory Lubricated additional...

Page 13: ...r no 2 Circuit Breaker CB2 Manual Reset Opens at 60 amps Excessive current draw by evaporator fan motor no 1 Circuit Breaker CB3 Manual Reset Opens at 60 amps Excessive current draw by condenser fan m...

Page 14: ...h set point then the evaporator fan motors will not operate when the thermostat is calling for heat Condenser Motor Overload COL1 and COL2 Each condenser fan motor is equipped with an internal thermal...

Page 15: ...ON position EFR1 and EFR2 relays are energized When energized a set of internal EFR1 and EFR2 contacts are closed to start the evaporator fan motors Evaporator Overload Relays OR1 and OR2 Evaporator o...

Page 16: ...nt supply of liquid is available to the evaporator coil as needed and as a storage space when pumping down the system The receiver is equipped with a sight glass to observe correct charge level and a...

Page 17: ...er Drier Outlet Valve 9 Thermostatic Expansion Valve 10 Evaporator Coil 11 Suction Line 12 Subcooler 13 Liquid Suction Heat Exchanger 14 Condenser Fan Switch CFS 15 Unloader Pressure Switch UPS3 16 Ch...

Page 18: ...ts to interrupt the compressor clutch circuit when the ambient temperature falls to 45_F 7 2_C Heat is then accomplished by cycling Boost Pump Motor BPM and Reheat Coolant Valve RCV to supply engine c...

Page 19: ...above the thermostat set point the HEAT COOL switch remains in COOL and the HIGH LOW switch remains in the HIGH position The thermostat discontinues supplying the signal to semi unload the compressor...

Page 20: ...2 3 T 288 Figure 2 2 Automatic High Speed Cool Mode Operation with Reheat TDR 10 SEC...

Page 21: ...2 4 T 288 Figure 2 3 Automatic High Speed Cool Mode Operation No Reheat TDR 10 SEC...

Page 22: ...2 5 T 288 Figure 2 4 Automatic High Speed Heat Mode Operation Below 45_F Ambient TDR 10 SEC...

Page 23: ...refrigerant flow Low refrigerant charge Service valves partially closed Safety device open Liquid line solenoid valve stuck closed 3 3 3 6 3 7 3 7 and 4 12 4 9 Open 1 4 Check 3 3 ABNORMAL PRESSURES Hi...

Page 24: ...s defective Motor brushes defective Evaporator fan loose or defective Return air filter dirty Icing of coil dirty coil Fan relays EFR1 OR EFR2 defective Safety device open Check 5 1 4 16 4 16 4 16 Cle...

Page 25: ...refrigerant lines Turning the valve stem counterclockwise all the way out willbackseat the valve to open the suction or discharge line to the compressor and close off the gauge connection In normal op...

Page 26: ...h O Ring Hose Fitting with O Ring Figure 4 2 R 134a Manifold Gauge Set Connections To service the refrigerant system the manifold gauge set is connected to the compressor suction low side service valv...

Page 27: ...d always be used whenever removing contaminated refrigerant from the system If a recovery system is not available proceed as follows a Equipment Required 1 Appropriate evacuated returnable refrigerant...

Page 28: ...the system prior to leak repair 8 Charge the unit as outlined in section 4 8 4 7 EVACUATION AND DEHYDRATION Proper evacuation and dehydration procedures are imperative when service repairs or compone...

Page 29: ...ifold vacuum pump vacuum gauge reclaimer and hoses as shown in Figure 4 4 All hand valves on manifold should be closed The compressor service valves should be midseated if used with service valve caps...

Page 30: ...Open filter drier inlet valve half way and allow the liquid refrigerant to flow into the unit Monitor weight of refrigerant cylinder to determine how much refrigerant is entering the system The corre...

Page 31: ...ight as viewed Finger tighten flare nuts h Tighten filter drier flare nuts using two open end wrenches i Install vacuum pump on filter drier inlet valve Evacuate to 500 microns and disconnect vacuum p...

Page 32: ...s No Continuity Switch Opens Continuity Switch Closes High Press ure HPS 300 10 psig 200 10 psig Low Press ure LPS 6 3 psig 25 3 psig Condenser Fan Speed CFS 250 10 psig 190 15 psig Unloader Pressure...

Page 33: ...firmly secured to suction line as shown in Figure 4 8 Place insulation around TXV bulb and thermocouple 4 Connect suction gauge to the service port on the compressor suction service valve 5 Set tempe...

Page 34: ...unger or deformed valve body assembly Failure to close may be caused by the following a Defective plunger or deformed valve body assembly b Foreign material in the valve It is not necessary to drain t...

Page 35: ...Clip Bolt 5 Venturi 6 Evaporator Motor 7 Hub Set Screw 7 Figure 4 10 Evaporator Fan Blower Assembly 4 16 1 Routine Examination and Cleaning a At regular maintenance periods remove brush covers and cl...

Page 36: ...second filter past the holding channel to the center position and remove e Repeat the above step with the third filter f Reverse the procedure for installing the new filters 4 18 COMPRESSOR 4 18 1 Rep...

Page 37: ...4 18 2 Checking the Compressor Oil Level NOTE It may be necessary to preheat the coach and or operate the system in the Reheat Mode to keep the compressor fully loaded throughout this procedure a Ope...

Page 38: ...n oil at all times Otherwise air and moisture will be drawn into the compressor 1 Connect manifold gauge set Place center charging line into compressor oil container as shown in Figure 4 12 Slowly ope...

Page 39: ...is no pressure at the oil drain plug d 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 c...

Page 40: ...5 0 26 0 26 70 21 71 1 490 2 5 00 4 90 4 20 4 6 31 7 0 32 0 32 75 24 78 7 542 6 5 53 5 43 2 19 5 6 36 6 0 39 0 39 80 27 86 7 597 8 6 10 5 98 0 18 6 5 44 8 0 46 0 45 85 29 95 3 657 1 6 70 6 57 2 17 7...

Page 41: ...5 1 INTRODUCTION This section contains Electrical Schematic Wiring Diagrams covering the Models listed in Table 1 1 Before performing operation and maintenance on the equipment ensure that precaution...

Page 42: ...HIGH PRESSURE SWITCH HR HEAT RELAY HR2 HEAT RELAY 2 LATH LOW AMBIENT THERMOSTAT LPS LOW PRESSURE SWITCH LSV LIQUID SOLENOID VALVE OR1 EVAPORATOR OVERLOAD RELAY 1 OR2 EVAPORATOR OVERLOAD RELAY 2 PTB P...

Page 43: ...5 3 T 288 Figure 5 2 Electrical Schematic Diagam Based on Drawing 68RM35 1038 12 TDR 10 SEC...

Page 44: ...1 4 7 4 8 Condenser Motor Overload 1 7 Condenser Speed Relay 1 4 1 7 1 8 Cool Disable Relay 1 4 1 8 Coolant Valve 3 2 D Description 1 1 3 1 Discharge Line Check Valve 1 2 Discharge Line Isolation Valv...

Page 45: ...Glass 1 2 Refrigerant Charge 1 5 Reheat Coolant Valve 1 5 2 1 3 2 4 9 Relay Board 1 1 1 4 1 8 Return Air Probe 1 4 S Safety Devices 1 5 1 6 3 1 3 2 Schematic Wiring Diagrams 5 1 Service Valves 3 1 Sub...

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