Request electrical schematic with solar/genny/batt/inverter

thomasinnv · August 28, 2011, 08:48:56 PM

hey Cliff it would be in.teresting to see what your 13.5 penguin pulls on hi fan no compressor. I have a 7.5K generac and I have run all 3 roof ac at over 100 deg. It was maxed out though. Turn any thing else on it would pop. I had an old class A years ago with 2 13.5 on it. The onan 6.5K would groan when you turned them both on. Couldn't have the fridge on Ac either or it would pop.

Uglydog56 · August 29, 2011, 08:15:35 AM

So how do you set up your electrical so it switches between solar, shore, and genny without having to crawl under the bus and switch cords around?

bevans6 · August 29, 2011, 08:25:07 AM

I switch between inverter (your solar), generator and shore with two very basic cascaded automatic transfer switches. Fully automatic, painless, around a $150 total for what I did. I use the following priority - shore, then generator then inverter.

What I did is have the first ATS connect to the shore as it's first priority choice and to the generator as it's alternate source. The output of that first ATS goes to the second ATS as it's first priority choice and to the inverter as it's alternate choice. Works great, there is about a second of lag between switching as the ATS decides power has been lost.
I use the Iota 30 amp ATS.
Brian

Uglydog56 · August 29, 2011, 09:59:41 AM

Perfect, thanks!

bobofthenorth · August 29, 2011, 10:41:30 AM

What Brian said except that the 2nd x-fer switch is internal to my Heart 2500 inverter. So the output from the first ATS goes to the inverter in pass through. If the inverter sees the power drop out it switches fast enough that we don't usually even lose the TV/DVD.

Uglydog56 · August 30, 2011, 04:13:13 PM

I started looking hard at inverters and the magnum I'm considering has the same feature.

pvcces · August 31, 2011, 09:42:06 PM

Mex-busnut, you said "Golf cart batteries are each usually 35 amps per hour for 20 hours."

They are usually 220 amp-hours.
Working backwards, I get 11 amps for 20 hours. And they weigh about 65 pounds.

I've seen low draw RV air conditioners advertised and they run 10-11 amps. I would go that route if I was looking for another unit. To figure 12 volt DC current draw of inverters running AC loads, it's very easy to multiply AC amps by 11 to allow for inverter losses.

What will throw you off more is the battery output voltage when it is heavily loaded. In a 12 volt system, it is not unusual to see a range of 11.5-14.5. That's about 20% drop from full voltage to low voltage. At least some of the difference becomes heat in the system, notably, the batteries.

We run one air conditioner(not a low draw) on our 220 amp generator without difficulty. The inverter is a blue case(marine) Xantrex Freedom 25. We had a green case 20, but that wouldn't start the AC.

Good luck.

Tom Caffrey