Ingersoll-Rand 900829, Maintenance Manual

Page: 52 / 142

Refrigeration Service Operations
50
8. Recharge the unit.
Drier
Removal
1. Recover the refrigerant charge.
2. Disconnect the ORS nuts at the ends of the
drier.
3. Loosen the mounting hardware and remove
the drier.
Installation
1. Coat the new O-rings with refrigerant oil
(same type that is used in the system) and
place the new O-rings in the ORS fittings on
the ends of the drier.
2. Install the new drier and tighten the mounting
screws and nuts.
3. Install and tighten the ORS nuts. Hold the
drier with a back-up wrench on the hex behind
the ORS fitting.
4. Pressurize the system and test for leaks.
5. Evacuate and recharge the system.
High Pressure Transducer
Removal
1. Recover the refrigerant charge.
2. Remove the condenser grille if necessary.
3. Disconnect the wires and remove the
transducer.
Installation
1. Install and tighten the switch and reconnect
the wires.
2. Pressurize the system and test for leaks.
3. Reinstall the condenser grille (if removed).
4. Evacuate and recharge the system.
Defrost Solenoid Test
1. Install a gauge manifold set on the engine
driven compressor.
2. Disconnect the 2-pin connector with the LIS
and CLU wires in main wire harness from
wires to the liquid injection switch at the
engine driven compressor.
3. On Model 30 and 50 units disconnect the
2-pin connector with the 26 and CHM wires in
main wire harness from the wires to the
condenser blocking solenoid.
4. Set the thermostat on the lowest setting.
5. Start and run the unit in Cool on the engine
driven compressor until the suction pressure
stabilizes.
6. Check the temperatures of the refrigeration
lines on both sides of the defrost solenoid by
hand. A temperature difference between the
two sides of the defrost solenoid indicates it is
leaking.
7. Use the In-Cab Control Box to place the unit
in defrost.
NOTE: The defrost termination switch must
be closed for the unit to enter defrost. Use a
jumper wire to connect the 12 and CHB
circuits in the main wire harness at the 2-pin
connector for the defrost termination switch
if the evaporator temperature is not low
enough to close the defrost termination
switch.
8. The suction pressure should rise. If the suction
pressure does not rise, the defrost solenoid is
not opening. Check the continuity of the
wiring and the solenoid coil before assuming
the solenoid is faulty.
9. Reconnect the wires that were disconnected
and remove the gauge manifold set when
finished with the test.
Liquid Injection Solenoid Test
See “Testing Liquid Injection Solenoid Valve and
Metering Orifice” on page 40.