Thermo King T-1000R, Maintenance Manual

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Refrigeration Maintenance 10-49
5. Front seat the suction service valve to isolate the low side while it is still in a vacuum.
6. Watch the low pressure gauge attached to the suction access port. The low side pressure should not rise. It it does, there could
be a leak through one (or more) of following components: hot gas solenoids, purge valve, or hot gas bypass solenoid.
7. Remove the remote evaporator covers from the remote evaporators in all the zones in which the suction line solenoids are
being tested.
8. Backseat the receiver tank outlet valve to allow liquid refrigerant into the liquid lines.
9. Use the Mechanics/Premium HMI Control Panel to enter the Interface Board Test Mode. Refer to the appropriate
Microprocessor Diagnostic Manual for specific information about the Interface Board Test Mode.
10. Energize the suction line solenoid in the zone being tested with the Interface Board Test Mode.
11. Use a jumper wire to jump the LLS terminal on the terminal board in the remote evaporator of the zone being tested to +12
Vdc to open the liquid line solenoid.
12. Watch the low pressure gauge attached to the suction access port. The low side pressure should not rise. If it does, the suction
line solenoid is leaking or not closing. Check the continuity of the wiring and the solenoid coil before assuming the solenoid
is faulty.
13. De-energize the suction line solenoid in the zone being tested with the Interface Board Test Mode.
14. Watch the low pressure gauge attached to the suction access port. The low side pressure should rise. If it does not, the suction
line solenoid is stuck closed.
15. Remove the jumper wire from the LLS terminal on the terminal board in the remote evaporator of the zone being tested.
16. Repeat steps 10 through 15 for the other zone (or zones) being tested. If the low side pressure rose enough to be equal with
the high side pressure when the suction line solenoid was de-energized, open the suction service valve and repeat steps 2
through 9 before repeating steps 10 through 15 for the other zone (or zones).
17. Back seat the suction service valve. Perform a “Refrigerant Gauge Removal” procedure.
SUCTION PRESSURE REGULATOR (SPR) TEST
1. Attach a gauge manifold to the suction service valve and the discharge service valve.
2. Operate the unit in high speed heat until the system pressures stabilize.
3. Check the suction pressure on the gauge attached to the suction service port. It should be within the range shown for the SPR
setting in the “Specifications” chapter. If the setting is incorrect, remove the protective cap and try to adjust the SPR to the
correct setting before assuming it is faulty.
4. Remove the gauges to return the unit to normal operation.
SUCTION PRESSURE REGULATOR (SPR) 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 and use the suction access port to access the low side.
2. Unsolder and remove the SPR. Note the position of the SPR so the new one will be placed in the same position.
Installation
1. Clean the tubes for soldering.
2. Place the new SPR in the same position from which the old one was removed.
3. Use a heat sink or wrap the SPR with a wet rag to prevent damage and solder the tubing connections.
4. Pressurize the low side and test for leaks.
5. If no leaks are found, replace the liquid line drier then evacuate the low side.
6. Open the refrigeration valves and place the unit in operation.
7. Run the unit and test the SPR. Adjust the setting if necessary.