Inverter wiring with shore power help needed

[WillTheThri11]

Hi all, I have a MagnaSine MMS1012 (inverter/charger) and wanting to replace my Iota DLS-30(converter charger only) with it to be able to use AC outlets while camping.

The question I have is how do I hook up the AC in/out on this properly?

The IOTA had a standard 3-prong plugged into a GFCI under the gaucho and outputs to the battery and chassis ground.

Do I wire AC in the same way or take the AC shore power from the breaker panel and pass it through the inverter and then the AC out to the main breaker?

The manual says never to hook up AC out to an AC power source but then has a caveat about a breaker being ok under certain circumstances in an RV. Unfortunately there are no full diagrams showing shore power, AC panel, Battery and inverter.

Can anyone help? I don’t wanna fry this thing or start a fire hehe

[Scalf77]

The first answer is to farm it out to a qualified electrician.

The second answer would be more of a question, What does your AC braker panel look like. Do you have 30 amp shore power.

And third, while you plug into the converter AC plug, it would only be size for 15 amps, your inverter/charger has 20 amp charge/pass-thru. This also not allow you to hard wire in existing receptacles.

So to do it correct will be a bit of work, which brings me back to the first answer.

[WillTheThri11]

I have 30amp shore power with a main breaker and 4 separate circuits on breakers in a GE panel (stock SMB circa 1997).

If I route the shore power into the inverter and then thru to the panel, I’ll just have to limit the amperage to 20A since that’s the max pass through, which the inverter has a setting for.

I guess what I’m wondering is, is that my best bet? I doubt I’ll really ever need the 30A ampacity

If it were simple enough to keep the 30A shore power but also hook in the inverter to all the same outlets, that’d be preferable.

I’ve wired my whole house, but it’s all AC, no DC inversion. I appreciate the comment on the electrician, but I prefer to learn and fully understand what’s in my vehicle in case something goes south, I’ll have a better shot at troubleshooting/fixing the issue.

[Scalf77]

Sure that makes sense, and being your comfortable with AC. I would change the 30-amp main breaker to a 20-amp main, This will ultimately limit your downstream power usage. So the 30 amp input going to the main breaker could move to the input of the inverter. The output could then move input of your new 20 amp breaker. It would also be a good time to look at installing a new main breaker on the input feed going to the inverter.

This is somewhat optional, depending on length, if you use something like the Blue Sea Systems 8077 AC Main, 30A. I don't think they sell a 20 amp version, so you could just replacing the breakers might be the easiest solution. This would provide you reverse polarity protection.

The size of your DC cables is going to be driven by their maximum continuous current load ( I believe 133 amps) and distance to the battery. You also may want to add in your 12 volt devices (standard sportsmobile fuse boxes are 40 amps). A ANL fuse and fuse block would be a good choice for the inverter fusing.

[WillTheThri11]

Thanks Greg!

I think what you're describing for the AC side is as follows (semi-graphically):

AC-Shore==|add AC-Main Breaker here|==>|inverter/charger AC in -> out|===>|Breaker panel main (becomes sub/distribution panel)|===>|AC loads|

The inverter itself has some sort of user programmable current limiter built into it and also says there are input and output breakers. I'm wondering if that's fine as-is to limit the 30A main breaker on the panel down to 20 (will likely set to 15 actually) as well as to avoid the breaker upstream of the inverter...curious on your thoughts though. A separate breaker upstream may be more reliable and safe overall, but sounds like overkill, especially since it won't be actually protecting the inverter from over-current if they only have 30A options.

For DC side, I have 2ft 4ga wires between the inverter and the battery directly. I don't have a cut-off switch or fuse here, but it sounds like I need to add the ANL on the positive side or one of these (?): https://www.amazon.com/Blue-Sea-7148...7-93deae8f9840

From the battery to the DC loads I have the SMB auto-resetting breaker in series with the fuse panel.

[Scalf77]

If I were to simplify I would just change the existing breaker (30 amp Main, to a 20 amp main) You can set the breakers for about to 15, I am not sure if that handles pass-thru. Then wire the shore to input. I would go with the SNL fuse over breaker in this application but it would work.

Yes, the upstream breaker would need to be 20 amp to be useful. I just don't see them making a 20 amp, and it would probably be easier to just change out the breakers to 20 amp. You could purchase all the parts and build your own. Or not use one at all.

You can also limit input by using the dogbone connector in the 20 or 15 amp shore power outlets also.

[WillTheThri11]

Thanks for the responses. I think i will get an ANL fuse for the hot side of the battery (guess i either chop the cable and get a holder with screw terminals or buy another cable)...I'll look into the 20A breaker for the Main/distribution panel, but it seems like the system is still protected by the breaker inside the inverter.

[1der]

For your battery cable protection these fuse holders work well and would use your existing cables.

[Big_ern_101]

In your diagram, black and white connect to the input and are fused by the breaker panel on your house, campsite, generator, etc. Red and white connect to the main on the existing sportsmobile AC distribution panel.
Yes you will need to derate your existing AC distribution panel from 30A to 20A if you pass everything thru your charger.

There are other fancier ways to wire it up and keep the full 30A when you are on mains power with 20 of the 30A available when you are on inverter power, but thats sort of one of those "if you have to ask, find someone who knows wiring" to do it.

[WillTheThri11]

Originally Posted by 1der

For your battery cable protection these fuse holders work well and would use your existing cables.

Attachment 49130

Thanks Ray, I'm going that route for sure...and for anyone else, I found that they are called MRBF fuses/holders