Check Refrigeration System
refrigeration
Description
The refrigeration system is running and discharge pressure is less than 5 psig (0.34 bar) higher than suction pressure for more than 30 seconds; engine and electric operation alarm only, or shut down if configured.
Activation Conditions
The refrigeration system is running and the discharge pressure is less than 5 psig (0.34 bar) higher than suction pressure for more than 30 seconds.
Unit Behavior
Engine Operation: Alarm only or (if configured for shutdown) engine and unit shutdown and alarm. Electric Operation: Alarm only or (if configured for shutdown) refrigeration system shutdown and alarm with PSCON still energized.
Reset Conditions
Auto reset when discharge pressure is more than 20 psig (1.36 bar) above the suction pressure when in alarm only, or auto reset after 30 minutes when shutdown is configured or alarm may be manually reset via keypad or by turning the unit off, then back on again.
Corrective Actions
1. Verify Compressor Is Running - Check compressor Amp draw - CCON T1-T2, T1-T3, T2-T3. Check all three voltage legs. Must be within voltage limits shown in Section 2.10. 2. Perform Pretrip Check - Clear Active Alarm list, then run Pretrip and check for any new alarms. Any active alarms must be corrected and cleared before proceeding. 3. Check System Pressures - Install manifold gauge set and check and compare compressor discharge and suction pressures with those shown on the microprocessor display. Suction pressure must be above 3 psig (0.2 bar) Discharge pressure must be more than 5 psig (0.3 bar) higher than the suction pressure. Suction and Discharge Pressures must have the same reading on gauges and on microprocessor display. 4. Check Compressor - Check compressor for excessive vibration or noise. Replace compressor. Refer to Section 8.8.