Low / Unbalanced A/C Amps
electrical
Description
The compressor is on and AC current is low or unbalanced, and the unit shuts down and alarms in engine operation or shuts down refrigeration in electric operation.
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 and 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 the Active Alarm list, then run a 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. Check related splice points. (See wiring schematic Section 10.3) Verify there is no physical damage to harness, and no damage, moisture, or corrosion in connectors.