Thermo King T-1000R, Maintenance Manual

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Refrigeration Maintenance 10-50
SUCTION PRESSURE TRANSDUCER TESTING (UT-SERIES AND T-SERIES EXCEPT
T-500R/T-DAIRY)
The suction pressure transducer is located on the suction adapter on the compressor. It supplies pressure information to the
SR-3 Microprocessor Control System. Alarm Code 87 (Check Suction Pressure Sensor) indicates a possible problem with the
suction pressure transducer. The pressure reading can be monitored with a Mechanics/Premium HMI Control Panel by
pressing
the
G
AUGES
key. Check the reading by
comparing it to the reading on a low pressure gauge attached to the suction service
valve port.
Refer to the appropriate Microprocessor Diagnostic Manual for more information about the testing and operation of the suction
pressure transducer.
SUCTION PRESSURE TRANSDUCER REPLACEMENT
Removal
1. Pump down the low side and equalize the pressure to slightly positive. Make sure to front seat the suction service valve to
isolate the low side.
2. Disconnect the wires and remove the suction pressure transducer from the suction adapter.
Installation
1. Apply a refrigerant Loctite to the threads of the suction pressure transducer.
2. Install and tighten the suction pressure transducer and reconnect the wires.
3. Open the refrigeration valves and check for leaks before placing the unit in operation.
THROTTLING VALVE TEST
1. Attach a gauge manifold to the fitting on the side of the throttling valve and the discharge service port. A low loss fitting must
be used on the hose connected to the discharge service port.
2. Operate the unit in high speed heat until the system pressures stabilize.
3. Check the suction pressure on the gauge attached to the fitting on the side of the throttling valve It should be within the range
shown for the throttling valve setting in the “Specifications” chapter. If the setting is incorrect, try to adjust the throttling valve
to the correct setting by adding or removing shims under the bellows spring before assuming it is faulty.
4. Remove the gauges to return the unit to normal operation.
THROTTLING VALVE REPLACEMENT AND REPAIR
Removal
1. Pump down the unit using the refrigerant recovery system.
2. Front seat the suction service valve. Release remaining pressure.
3. Remove the suction service valve.
4. Unbolt and remove the throttling valve from the unit.
Disassembly
1. Remove the piston end cap.
2. Remove the cotter pin from the castle nut and remove the nut.
3. Remove the spring and piston.
4. Loosen all the bolts on bellows end cap.
CAUTION: This end cap is under slight spring pressure.