Inverter with built in transfer switch.

[Trobec]

Hi everyone!
I have a quick question for those in the know. I bought a AIMS 2000 watt inverter with a built in automatic transfer switch that is hard wire only. Let me know if I’m understanding this correctly.

1. I disconnect the wires from the shore power/gen transfer switch that go to the A/C panel

2. Then run wires from the input side of the inverter to where the A/C panel wires were on the transfer switch.

3. Then connect the wires that go to the A/C panel to the output side of the inverter.

4. Turn off converter breaker to run inverter?

[KMP44]

#1 & # 2, yes. Inverter goes between the transfer switch for the generator and the ac load.

#3 - be careful. In theory, you could run to the main ac panel if you have a big enough inverter and battery bank. Need more info on that. If you did a 'whole house' inverter, yes, you need to shut off the converter. But that still leaves things like the air conditioner, fridge, and electric water heater powered from the inverter. That might still be more load than your inverter & batteries can handle. You may need to isolate more than just the converter to limit the amp draw.

Otherwise you are going from the inverter to a sub panel, where you have split off just the things you want to run on the inverter, like your outlets and maybe the microwave.

Search around and you can find good wiring diagrams for sub panel installs.

[unyalli]

Correct. Obviously you know a bit about this so goes with out saying being frugal with your 16 amps of AC power.

[Trobec]

Originally Posted by KMP44

#1 & # 2, yes. Inverter goes between the transfer switch for the generator and the ac load.



#3 - be careful. In theory, you could run to the main ac panel if you have a big enough inverter and battery bank. Need more info on that. If you did a 'whole house' inverter, yes, you need to shut off the converter. But that still leaves things like the air conditioner, fridge, and electric water heater powered from the inverter. That might still be more load than your inverter & batteries can handle. You may need to isolate more than just the converter to limit the amp draw.



Otherwise you are going from the inverter to a sub panel, where you have split off just the things you want to run on the inverter, like your outlets and maybe the microwave.



Search around and you can find good wiring diagrams for sub panel installs.

I have 400 amp hours of lithium batteries and 550 watts of solar running through a mppt charge controller and a 2000 watt inverter and a 4000 watt gen set.

Basically what I want is to be able to run my outlets,maybe the microwave and the option of running my fridge on electric on travel days so i can turn off my propane. My water heater is 12 volt on demand.

I want everything to be pretty much automatic. I don’t want to have to turn off breakers. Kinda defeats the purpose of the transfer switch. I just don’t know how to make that happen. Yet.

[unyalli]

You will want to turn off the converter. Don't want to power the converter off batteries.

[Trobec]

Originally Posted by unyalli

Correct. Obviously you know a bit about this so goes with out saying being frugal with your 16 amps of AC power.

Right? I don’t run the inverter much. Just want to make a pot of coffee in the morning and maybe a little tv at night without firing up the generator.

[ependydad]

Originally Posted by Trobec

I want everything to be pretty much automatic. I don’t want to have to turn off breakers. Kinda defeats the purpose of the transfer switch. I just don’t know how to make that happen. Yet.

KMP44 is right, if you want everything automatic and to not have to throw breakers, you'll need to add a subpanel that either gets its power from the inverter (or via shore power with the inverter's built-in ATS).

Originally Posted by KMP44

Otherwise you are going from the inverter to a sub panel, where you have split off just the things you want to run on the inverter, like your outlets and maybe the microwave.

Search around and you can find good wiring diagrams for sub panel installs.

[KMP44]

Originally Posted by Trobec

I have 400 amp hours of lithium batteries and 550 watts of solar running through a mppt charge controller and a 2000 watt inverter and a 4000 watt gen set.

Basically what I want is to be able to run my outlets,maybe the microwave and the option of running my fridge on electric on travel days so i can turn off my propane. My water heater is 12 volt on demand.

I want everything to be pretty much automatic. I don’t want to have to turn off breakers. Kinda defeats the purpose of the transfer switch. I just don’t know how to make that happen. Yet.

So, you have a pretty solid setup as far as batteries & solar, and the 4kw generator will give you plenty of power. I'm not sure what kind of draw that water heater will pull, but it doesn't matter in relation to the inverter since its 12V.

Seems like the choice is run your wire to the main breaker in the panel and flip the converter and probably air conditioner (and what else - fire place?) off before using the inverter. Or take the circuits you want powered into a sub panel. The sub panel is definitely more work up front, but then the operation is automatic. Shore/generator power not present, inverter powers the sub panel via the built in transfer switch. I went this route, because invariably at some point I'll fail to turn off or turn back on something and cause myself problems.

For a 2,000 watt inverter, for a sub panel setup, you would leave the wiring alone from the shore power and generator into the main panel. In the main, you probably go with a 20 amp breaker that feeds the input of the inverter. Output of the inverter goes to the sub panel. Then you move the breakers for the fridge, outlets, microwave from the main panel to sub panel.

In some rigs, that's not to much of hassle, in others it can be a real job depending on where everything is located. Inverter needs to be as close as possible to the batteries, then find a workable layout for the rest. I had a good diagram that I can't seem to find. It showed the concept, then from there you have to figure out the specific locations and wire runs based on your rv. I'll post it later if I can find it...

[jbflag21ds]

Originally Posted by ependydad

KMP44 is right, if you want everything automatic and to not have to throw breakers, you'll need to add a subpanel that either gets its power from the inverter (or via shore power with the inverter's built-in ATS).

Or return the inverter he bought and get a 3kW inverter charger. He's wanting to wire it up the same way, before the distribution panel. This way he can skip the sub panel, bypass/remove the converter, and be 99% automatic.

[Trobec]

Originally Posted by ependydad

KMP44 is right, if you want everything automatic and to not have to throw breakers, you'll need to add a subpanel that either gets its power from the inverter (or via shore power with the inverter's built-in ATS).

Well,considering how infrequent I run my inverter, I think I will just wire it to the breaker panel and just shut off the things I don’t want to run. Seems like the easiest and most cost effective way to do it. Thanks for everyone’s input!

[KMP44]

Originally Posted by jbflag21ds

Or return the inverter he bought and get a 3kW inverter charger. He's wanting to wire it up the same way, before the distribution panel. This way he can skip the sub panel, bypass/remove the converter, and be 99% automatic.

Yes - inverter/charger is nice. It also gives the LiFPo batteries the correct voltage when charging. I balked at the price and just put in a 3000W inverter. I still wonder if I should have just done an inverter/charger instead. But, I probably still would have done the sub panel since we have a 50 amp main panel and 2 air conditioners so the sub panel would still be a good way to limit the load in that case.

Or, I came across a YouTube video of a setup with two 3,000 watt inverter chargers powered by like sixteen 100AH lithium batteries running everything. Pretty slick, but can't image what it costs or what it weighs. Definite overkill for making coffee or running the microwave for a couple minutes, but fun to watch:

https://www.youtube.com/watch?v=FbaveTiNVco&t=24s

[CHICKDOE]

maybe i'm crazy but i don't think so without some thought! here's why.

you seem to be planning on running all shore power requirements through the new inverter. remember the entire shore power load goes though the existing shore power / generator transfer switch. so now you are planning on running that all through the inverter. a 2000 watt inverter is can probably handle 16 amps max (2000 watts / 120 volts). your shore power is at least 30 amps. will the internals of the transfer switch handle the possible 30 amps?

how are you going to isolate the generator supplied power. that is the job of the existing transfer switch? if you disconnect the output of the existing transfer switch and connect them to the new inverter, you will have to connect to get generator power. if you leave them connected to the output of the existing transfer switch and run new wires from the inverter output to the ac panel you have to possibility of cross connecting between shore and generator power. why have a generator if you can't use it?

perhaps i misunderstand but this is what struck me.

[unyalli]

Don't confuse transfer switches. The existing has two inputs one from shore one from generator. It ensures only one is allowed through to the power panel. Running this existing transfer switches output through the inverters internal transfer switch allows either shore/gen through to the power panel or the inverters output to the power panel.

[jbflag21ds]

Originally Posted by CHICKDOE

maybe i'm crazy but i don't think so without some thought! here's why.

you seem to be planning on running all shore power requirements through the new inverter. remember the entire shore power load goes though the existing shore power / generator transfer switch. so now you are planning on running that all through the inverter. a 2000 watt inverter is can probably handle 16 amps max (2000 watts / 120 volts). your shore power is at least 30 amps. will the internals of the transfer switch handle the possible 30 amps?

how are you going to isolate the generator supplied power. that is the job of the existing transfer switch? if you disconnect the output of the existing transfer switch and connect them to the new inverter, you will have to connect to get generator power. if you leave them connected to the output of the existing transfer switch and run new wires from the inverter output to the ac panel you have to possibility of cross connecting between shore and generator power. why have a generator if you can't use it?

perhaps i misunderstand but this is what struck me.

shore power -> ATS
generator -> ATS

ATS -> inverter
battery bank -> inverter

inverter -> main panel

as long as the inverter can pass through 30amps via it's internals, its ATS included, then he should be fine. OP needs to check the specs of the unit he wants to use if I am understanding how he wants to connect

If it can't handle 30 amps, then get a bigger unit or it's sub panel time.

[CHICKDOE]

Originally Posted by unyalli

Don't confuse transfer switches. The existing has two inputs one from shore one from generator. It ensures only one is allowed through to the power panel. Running this existing transfer switches output through the inverters internal transfer switch allows either shore/gen through to the power panel or the inverters output to the power panel.

except in his point #1 he says disconnect the wires running from the existing transfer switch to the ac panel and run them to the output of the inverter transfer switch. those wires carry both shore power and generator power to the ac panel. without them you don't have generator power.

[CHICKDOE]

Originally Posted by CHICKDOE

except in his point #1 he says disconnect the wires running from the existing transfer switch to the ac panel and run them to the output of the inverter transfer switch. those wires carry both shore power and generator power to the ac panel. without them you don't have generator power.

after reading for about the 4th time i think the routing being proposed would be

1. shore and generator input to the existing transfer switch
2. existing transfer switch output to shore input of inverter
3. inverter output to ac panel (this would be either the input from shore / generator or inverter produced power.

in theory i guess this would work. but i'd still be worried about running all of the 30 amp load through the inverter. normally they are connected so that only one 15 amp branch circuit is run through them.

[ScottBrownstein]

While it looks like the transfer switch is rated at 30 amps, you still need to turn off the converter, unless the inverter has a built in charger, which many do. I would use a subpanel anyway...cleaner and only powers what you want.

[DES-1]

This thread proves there are allot of ways to do this. I'd encourage you to think before you do.


You don't need a new sub-panel. You can keep the wiring simple IF you just power the A/C panel so everything is on, and use your smarts not to try to run too many circiuts. You do need to make sure you power the 12v converter from a dedicated shore power/gen line which should have an inline breaker. I'd be hesitant to use a combo inverter/transfer unless it is super quality.

[Trobec]

I think this is the setup that is going to get me where I want to be. Just stumbled across this. What do you think?

https://youtube.com/watch?v=lqXngyKtZtc&feature=share

[JimM2109S]

If you wanted "automatic", you could wire the converter input wires directly to the generator/shore power side of the existing transfer switch. The converter would not receive power when running on the inverter. The inverter output would connect to the a/c panel.