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dssl · 09-18-2021, 05:35 PM

I am planning to upgrade my inverter and add lithium. I have decided on a Magnum msh3012rv hybrid inverter.

I have a 34 ft class A. I want to connect everything in the coach with the exception of the water heater to the inverter. That way I should be able to run anything (obviously not everything) off the inverter plus when I have a 30 amp connection I should be able to pull more then 30 amps as long as the average is not over 30 amps.

I understand that others have done this using 10 guage wire which I am puzzled by. 10 guage can handle 30 amps which is plenty for me when hooked up to 50 amps since there are 2 legs which are out of phase. My concern is when hooked up to 30 amps or when running the generator where the 2 legs will be on the same phase and thus the neutral leg will need to carry well over 30 amps at times(think both AC plus microwave and maybe coffee maker or toaster).

Why do others with this inverter not have problems with 10 guage wire?

I am leaning towards using 6 guage wire although 8 guage may be okay. I suppose another option would be to use 10 guage wire but somehow double up the neutral wire by using a 4 conductor plus ground wire or maybe split those wires over 2 cables.

Does anyone using this inverter have any insight on AC wiring?

TIA.

dssl · 09-18-2021, 08:23 PM

For some reason it doesn't give me the option to edit the post.

Was trying to research about doubling up the neutral wire and it sounds like that isn't considered kosher, so I shouldn't consider that. I guess I could maybe use a 10/2 wire for the hot wires and ground and then a separate 6 guage wire for the neutral .

HarryStone · 09-18-2021, 09:12 PM

I would think that a 3k inverter would not be sufficient to pass current enough for 2 AC units along with say a microwave. Go online and read the manual on the inverter. You will probably find that 10 gage is recommended for that inverter. Your neutral wire should never carry the full load of the power source.

dssl · 09-18-2021, 09:18 PM

Quote:

Originally Posted by HarryStone

I would think that a 3k inverter would not be sufficient to pass current enough for 2 AC units along with say a microwave. Go online and read the manual on the inverter. You will probably find that 10 gage is recommended for that inverter. Your neutral wire should never carry the full load of the power source.

It's a hybrid inverter with a 50 amp X 2 bypass. The idea is if the generator or 30 amp shore power isn't sufficient it can add. For example if you had a 30 amp source you could pull more then 30 amps.

The manual recommends 6 guage wire. But I will never draw near 50 X 2 amps so it's a bit of overkill to use 6 guage wire except for the neutral.

twinboat · 09-18-2021, 11:40 PM

You may never draw 50 amps x 2 but you certainly could draw more the 30amps on one leg or the other.

Since your 50 amp shore power input is running thru this inverter, use 6 gage wire, as recommended.

While on 30 amp shore power, the hybrid inverter is designed to boost that amperage above that, up to 50 amps.

dssl · 09-19-2021, 07:13 AM

Quote:

Originally Posted by twinboat

You may never draw 50 amps x 2 but you certainly could draw more the 30amps on one leg or the other.

Since your 50 amp shore power input is running thru this inverter, use 6 gage wire, as recommended.

While on 30 amp shore power, the hybrid inverter is designed to boost that amperage above that, up to 50 amps.

I was thinking of having 30 amp fuses but I guess it's silly I may as well just go with 6/3.

Next question not sure if you know. When I search for 6/3 wire this THN wire which is for submersible pumps comes up at a very good price. I was assuming I would use romex nm wire but if this is cheaper. Do you know if it would be appropriate?

https://nassaunationalcable.com/products/6-3-heavy-duty-flat-grnd-thw-copper-600v?gclid=Cj0KCQjwv5uKBhD6ARIsAGv9a-zT6FUc9_G4rLfcYIX2uDsVd0zYYVtAAVN2-G48AkqZFRtxumK-KEYaAtTMEALw_wcB