Onan Generator Question

[smlranger]

I've recently discovered that if my coach is connected to shore power and you start the genset (Onan quiet diesel 7.5KW), the generator will run for less than one minute and abruptly shut down. If I shut off the shore power (flip the breaker at the power pedestal), the genset runs fine.

While I routinely would not need to run the genset if I have shore power, I would think the transfer switch could handle both inputs and just put the genset offline.

Is this generally the way these set ups work or do I have a problem with my transfer switch?

[Flagelpater]

I am not an Expert, however, the GenSet normally has priority, if it is producing power it will force the transfer switch to allow it to power the house. It is a mechanical device that should not allow both Shore and GenSet power to be provided at the same time. What unit do you have and what model GenSet? Are you minimizing the load before you turn the GenSet On? It sounds strange to me also that it works okay with shore power turned off.

[GaryKD]

Hi smlranger,
I agree with the previous post. The problem may be with the initial load being too much for the generator. This is because if the generator shuts down, we are talking about the mechanical engine. I know when my high wattage appliances kick in the generator must speed up considerably to deliver the electrical load. It is quite noticeable.

There could be a problem in the transfer switch, I've just never heard of the symption you describe being the transfer switch.

[RV Wizard]

I also think the load to too much for a sudden, cold generator output. Reduce the load of the coach before starting the generator. Let the generator warm up even beyond what the transfer switch allows and slowly add more load until you have it fully loaded. Let us know what you find.

[hamguy]

Quote:

Originally Posted by smlranger I've recently discovered that if my coach is connected to shore power and you start the genset (Onan quiet diesel 7.5KW), the generator will run for less than one minute and abruptly shut down. If I shut off the shore power (flip the breaker at the power pedestal), the genset runs fine. While I routinely would not need to run the genset if I have shore power, I would think the transfer switch could handle both inputs and just put the genset offline. Is this generally the way these set ups work or do I have a problem with my transfer switch?

Does it shut down when the xfer switch activates. If so (and it sounds like that is the case) it might be you have too much loading for the cold engine. Shut down the loads and try it that way. Good luck.

[smlranger]

Thanks for all the suggestions. When I was doing this, I did not think I had much of anything turned on the the coach to add load but I did have the heat pump set for heating and, frankly, wasn't paying much attention to whether or not it was actually on when I tried to start the genset.

So, last evening I tried again, making sure there were no loads on the system. Started genset with shore power on and it ran just fine. The transfer switch defaulted to the genset until I shut the generator down.

All is well. Thanks, again.

[JoeT]

Is this a great forum, or what?