Overview:
There are no easy solutions. Finding wiring shorts requires compartmentalization of wiring in order to narrow the search area.
Process (Steps 1-13):
1. Does the 24VAC transformer breaker trip as soon as power is applied to the unit? If no continue to the next step, if yes then go to step 3.
2. Does the 24VAC transformer breaker trip during unit operation specifically when a particular component is started/engaged? If no turn off the main power to the unit then jump to step 10, if yes turn off the main power to the unit, find the appropriate connector on your control schematic, then jump to step 12.
3. Turn off the main power to the unit.
4. Remove all connections and or plugs (including thermostat, zone sensor, or BAS wiring)from the RTRM (Reliatel Microprocessor unit).
5. Per the schematic locate the connector that supplies 24VAC power to the board from the 24VAC transformer.
6. Orient that connector (45° or 90°) such that you only attach the pin that provides 24VAC power to the board and attach the connector (single pin only).
7. Restore power to the unit.
8. Does the 24VAC transformer breaker trip as soon as power is applied to the unit? If yes continue to the next step, if no then go to step 10.
9. Replace the RTRM (Reliatel Microprocessor unit). Jump to end.
10. Remove all connectors (including thermostat, zone sensor, or BAS wiring)from the RTRM (Reliatel Microprocessor unit).
11. Replace 1 connector at a time (beginning with the connector that provides 24VAC input to the board). Restore power after each connection to see if the breaker trips. If not shut down power and connect the next connector (and so on).
12. Once you locate the connector that trips the breaker use your unit schematic to thoroughly troubleshoot the appropriate wiring. Check for loose wiring, mis-wiring, failed components, etc. Jump to end.
13. 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.