Tripp Lite SRCOOL33K, Service Manual

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9. Basic Test Procedure
If the test shows:
• Below normal high side pressure,
• Above normal low side pressure,
• Low temperature difference across coil,
Then the compressor valves are faulty; replace the compressor.
9.1.4 Compressor Thermal Overload (Internal)
The compressor is equipped with an internal overload. The overload is embedded in the motor windings to sense the winding
temperature and/or current draw. The overload is connected in series with the common motor terminal.
Should the internal temperature and/or current draw become excessive, the contacts in the overload will open, turning off the
compressor. The overload will automatically reset, but may require several hours before the heat is dissipated.
9.1.5 Testing the Internal Overload for Failure
If sufficient time has passed to allow the compressor to cool and the compressor still does not operate without any errors
displayed, it is possible the internal overload is defective.
1. Make sure there is no power to unit, then remove the leads from the compressor terminals.
2. Using an ohmmeter, test continuity between terminals C-S and C-R. If not continuous, the compressor overload has failed
and the compressor must be replaced.
9.2 Sealed Refrigeration System Repairs
9.2.1 Equipment Required for Refrigeration System Repairs
• Voltmeter
• Ammeter
• Ohmmeter
• E.P.A.-Approved Refrigerant Recovery System
• Vacuum Pump (capable of 200 microns or less vacuum.)
• Equipment for Copper Pipe Repair
• Electronic Halogen Leak Detector (G.E. Type H-6 or equivalent.)
• Accurate Refrigerant Charge Measuring Device:
o Balance Scales - 1/2 oz. accuracy
o Charging Board - 1/2 oz. accuracy
• High Pressure Gauge - (0 - 400 lb.)
• Low Pressure Gauge - (30 - 150 lb.)
• Vacuum Gauge - (0 - 1000 microns)
• Nitrogen
9.2.2 Equipment Requirements
The equipment required for refrigeration system repairs must be capable of:
• Recovery CFCs as low as 5%.
• Simultaneous evacuation from both the high-side service port (HP) and the low-side service port (LP).
• Introducing refrigerant charge into high side of the system.
• Accurately weighing the refrigerant charge actually introduced into the system.
• Facilities for flowing nitrogen through refrigeration tubing during all brazing processes.