davidsteverson Report post Posted December 2, 2016 Greetings everyone. We have been parked in our winter resort for about 6 weeks now. We try and run the generator under a load every 6 - 8 weeks so today was the day. Cranked all 3 ACs down to 70 so they would all come on and headed out to unplug from the 50 amp shore power we are connected to. My wife says no need to do that - the generator overrides the shore power. For what it's worth, my wife grew up with a dad and 3 brothers who could fix anything. I know nothing - so she is usually correct. Any input you can give me? And I don't mind being wrong - just don't want to hurt anything by running the generator for 2 hours while plugged in to shore power. Thanks, everyone. Share this post Link to post Share on other sites
wildebill308 Report post Posted December 2, 2016 You won't hurt anything all the coach I have had experience with were set up this way. When you are ready to shut down the generator take all the load off and let it run for about 5-10 min to cool before shutdown. Bill Share this post Link to post Share on other sites
kaypsmith Report post Posted December 2, 2016 She is correct in most coaches that have an ATS which will change the load over, but to swap over under load is not the best way, as this can damage the contacts in the ATS thereby shortening the life of the ATS. Share this post Link to post Share on other sites
BillAdams Report post Posted December 2, 2016 Your wife is correct. However, some folks like the "belt and suspender" approach which is to flip the breaker at the power pole and then start the generator. Personally, I don't do that and I have suffered no ill effects. The intended function of your transfer switch is to handle this exact situation. You start the generator and nothing happens until the generator is provider the proper 120V service at which time a nearly instantaneous transfer of power takes place. What I would do differently is turn OFF the A/C units when you want to do a power transfer. Let the transfer take place and then turn the A/C units back on 1 at a time. Share this post Link to post Share on other sites
wolfe10 Report post Posted December 2, 2016 Bill is correct on both counts: Best to NOT transfer with heavy loads on, as that burns/pits the contacts in the ATS. The ATS is designed to transfer to generator even if shore power is connected without issues. BUT, personally, I always disconnect before starting the generator-- guess I am a "belt and suspenders" guy. SO, best practices when switching from shore power to generator: Turn off all large loaded in coach. Turn off CG breaker. Unplug shore power. Start generator. After a couple of minutes warm up time, turn back on heavy loads in the coach. Is this totally necessary? Perhaps not, but is is the "easiest" on the electrical system. Share this post Link to post Share on other sites
john_harris Report post Posted December 2, 2016 Glad to have the clarification. While I too suspected that this was the case, I have always unplugged or tripped disconnect just to be on safe side. Like Brett, seemed to be best practice and eliminated potential for something not working as it should. Share this post Link to post Share on other sites
davidsteverson Report post Posted December 3, 2016 Thanks everyone. It looks like I did everything right until the very end. I started the generator (leaving the 50 amp shore power connected). I then started the ACs and let them run for about 110 minutes. However, I didn't look at the answers you all gave prior to shutting down. The ACs were running and I just turned the generator off. I'll know better next time. Thanks for all the good replies. Share this post Link to post Share on other sites
