Plugged in and Generator

2oldman wrote:
Please enlighten us.. why would you be doing that?

I don't know that I would "NEED" to do it but as I was troubleshooting yesterday (I think it ended up being bad chassis batteries) I had it plugged into 120v and started the generator. I'm just trying to rule out that that is causing any of my issues (that was before I had figured out the chassis batteries weren't working right.

With Transfer switches, it is NEVER a good idea to transfer power under any load. Regardless of Shore Power or Genset. The reason is, there are contac points in a transfer switch and transferring under load will cause those points to arc and slowly build up deposits on those points until one day they fail to make contac even tho they close. The best way to transfer is to turn the MAIN breaker OFF at your inside Breaker panel and then either connect to Shore or allow the Genset to transfer, then turn the breakers ON. There is NO system out there that if wired to code will cause a problem (hazard), by turning the genset on when connected to shore power. Or Vice/Versa. Doug

Best to make it a habit that you unplug shore power when you run the generator. It MIGHT be wired correctly, but honestly...as much as it costs to repair stuff on our coaches....why risk it?

And you can definitely run the engine when the genny is running. Most everyone does it during the summer so they can run the house air conditioners while on the road.

Please enlighten us.. why would you be doing that?

On my Monaco coach, when the generator is started, and up to power, the transfer switch will shift from shore power to generator power. No harm done but it is best to check your owner's manual for each coach as many are different.

The automatic transfer switch does a good job. But, I always unplug from shore power before I start the generator. Just in case.

The auto transfer switch will not let the generator power connect when you have shore power. Sometimes when I run the engine while on shore power my battery/alternator light will come on but it does not hurt anything.

That's a great question. My book tells me not to run the generator when plugged in to shore power.
But, our old motor Home you could be plugged into shore power, and still run the generator.
I guess it all depends on the coach.

Most motorhomes have a "transfer switch" that prevents interconnecting problems. What isn't for sure is if it will switch to generator as long as you're plugged in or not. Some will, some won't. Starting the engine won't have any effect.

Depends on if the rig is properly wired. If it is, no problem. If not, kiss the generator goodbye.