The Two Compressor Run alarm occurs whenever the two units are required to use mechanical cooling at the same time. This alarm is an early warning that one of the units may have reduced cooling capacity.
Troubleshooting
| Possible Cause | Component to Check | Recommended Action |
| Reduced sensible capacity of lead unit | Air filter, condenser, refrigerant charge | Replace filter, clean condenser, and recharge refrigerant. |
| One unit unable to use mechanical cooling | Use step test to verify compressor operation on both units | Refer to A07, High Temp Alarm to troubleshoot compressor |
| Shelter heat load exceeds rated sensible capacity of an individual unit | Shelter heat load, unit sensible capacity | Add/upgrade unit. Reduce heat load by shutting down unused equipment. |
| Exceptionally high outdoor temperature (>>95˚F) | Expected behavior | Ensure site is not “leaky” and allowing hot air through holes in the shelter |
| Improper lag unit turn on point | F38 under L05 Menu | Recommended at least 5°F for F38 |