Low / Unbalanced A/C Amps
electrical
Description
The compressor is on with low or unbalanced A/C amps, and the unit shuts down and alarms or shuts down refrigeration and alarms.
Activation Conditions
The compressor is on and AC Current Sensor 1, 2 or 3 is less than 5 amps for 10 seconds. OR, if the difference between AC Current 1 and AC Current 2, 2-3 or 1-3 is greater than 10 amps for 10 seconds.
Unit Behavior
Engine Operation: Engine and unit shutdown and alarm. Electric Operation: Refrigeration system shutdown and alarm with PSCON still energized.
Reset Conditions
Change unit to Electric Operation when AC Current Sensor 1 and 2 is greater than 7 amps for five minutes AND difference between AC Current 1 and AC Current 2 is less than 7 amps for five minutes OR alarm may be manually reset via keypad or by turning the unit off, then back on again.
Corrective Actions
1. 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. 2. Check Current Draw a. Use a clamp around A/C ammeter to check amps at power wires. Must be 1.0 Amp of reading in Unit Data. b. Check A/C amps with compressor running. Must be greater than 5 Amps. c. Compare A/C Amp readings between L1-L2-L3. Maximum allowable difference is 10 Amps. 3. Check Wiring - Inspect wiring from CT to CCB-31, 34, 12, and 10. Check related Splice Points. (See wiring schematic Section 10.2) Verify there is no physical damage to harness, and no damage, moisture, or corrosion in connectors.