Cannot Pump Down
refrigeration
Description
With SV1, SV2, and SV4 closed, the compressor cannot pull the low side down to 10 PSIG (0.68 bar), and Pretrip aborts with “PRETRIP FAILED IN TEST 12, 13 or 14” in MessageCenter.
Activation Conditions
With SV1, SV2, and SV4 in the closed position, the compressor is not able to pull the low side of the refrigerant system down to 10 PSIG (0.68 bar).
Unit Behavior
Pretrip will abort and “PRETRIP FAILED IN TEST 12, 13 or 14” will be displayed in MessageCenter.
Reset Conditions
Auto reset if Pretrip is started again, or alarm may be manually reset using the display mounted keys or by turning the unit off, then back on again.
Corrective Actions
1. Check Compressor Drive Coupling: Verify that compressor coupling is intact and the compressor crankshaft is turning. Repair as required. 2. Check System Pressure: Check and compare compressor discharge and suction pressures with those shown in unit data. Refer to Section 1.9.12 for instruction on comparison. 3. Manually Check Refrigeration System: Perform a low side pump down, refer to Section 1.7.2. Suction pressure must drop to at least 0 psig. If this check does not pass, continue to Check Compressor Pump Down. 4. Manually Test Refrigeration System: See Refrigeration Troubleshooting, Section 1.3.3, for “System Will Not Pump Down”. Must pass all tests.