Process (Steps 1- 12):
1. Is the red light lit on the unit's phase monitor? If yes, continue to the next step. If no, then continue on to step 11.
Image 1. Phase Monitor
2. Does the unit have line voltage? If yes, continue to the next step. If no, then continue on to step 6.
3. Is the unit missing line voltage on any of the three phases? If no, continue to the next step. If yes, then continue on to step 8.
4. Is the control wiring to the phase monitor correct (Refer to unit control schematic)? If yes, continue to the next step. If no, then continue on to step 10.
Image 2. Phase Monitor Installed
5. Is The main power to the unit reverse phased? If yes, then two power lines need to be swapped at the incoming power disconnect by a licensed electrician. If no, then the Phase monitor may be defective and needs to be replaced. Jump to End.
6. Is the unit disconnect shut off? If yes continue to the next step. If no then continue on to step 9.
7. Turn on the unit disconnect. Jump to End
8. Verify which unit fuses are blown. Replace as necessary. Jump to End.
9. Contact building maintenance for location of upstream circuit breaker and verify it is switched on. Jump to End.
10. Correctly install control wiring to the phase monitor per unit schematic. Jump to End.
11. Check to see if the unit shutdown circuit is open (Verify ~24VAC at Low Voltage Terminal Board pin 6).
12. End
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.