Originally Posted by Gettin there
Hello: Totally confused, Some say automatic transfer switch other say no. Looked everywhere for auto trans switch no luck or do not know what I am looking for.Generator- Generac series 50G model 9712-1 Motor home 1995 ford Conquest 102, Generator starts and runs great but with no power to cabin.Any help would be greatly appreciated.
Somewhere in the coach there is a transfer switch that prevents power being delivered to your 120V from both shore power and generator power at the same time, a condition definitely to be avoided. It is not part of the Generac unit and sits in a box of its own, typically 6" x 6" x 4" deep. In its non-energized state, the transfer switch permits power to pass from shoreside to your 120V breaker panel. When you start up the generator, it provides power to the relay in the transfer switch that disconnects the shoreside input and permits the generator to supply power to your 120V breakers.
Fire up the generator, turn on the breakers on the generator control panel and test one of the 120V outputs on the generator control panel with an appliance. If power isn't present, the generator motor runs, but no power is being delivered. If power is present, the generator is OK and the next suspect is a non operasting transfer switch.
When a generator delivers 120VAC to a properly operating transfer switch, there is typically this sequence:
1. Generator applies 120VAC to a circuit board in the transfer switch.
2. The circuit board delays firing the transfer switch relay for a preset period to permit the generator to come up to speed.
3. The transfer switch circuit board then rectifies the 120VAC to 120V DC and delivers it to the 120 VDC relay winding in the transfer switch which disconnects the shore power path and connects the path from the generator to the 120V breaker panel.
If the generator output is validated, the transfer switch should be located. The front panel is usually hinged and can be exposed to permit probing the relay winding contacts with a volt meter to determine if the relay is getting energizing voltage. Needless to say, caution should be exercised when dealing with exposed lethal voltages.
If there is 120VAC fouund at the input of the transfer switch circuit board but no 120VDC voltage on the relay winding contacts , the circuit rectifier board is bad. If 120VDC is found on the relay winding contacts, either the relay winding is open or some power contacts are sticking or have welded making the relay physically inoperable and will require replacement.