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Home » Public Forums » GMCnet » 120Vac Wiring from Onan to Coach, 75' Avion w/ 6k Powerdrawer (Does the LII connect to the chassis?)
Re: [GMCnet] 120Vac Wiring from Onan to Coach, 75' Avion w/ 6k Powerdrawer [message #316625 is a reply to message #316624] Tue, 25 April 2017 20:38 Go to previous message
A Hamilto is currently offline  A Hamilto   United States
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Registered: April 2011
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Jim Miller wrote on Tue, 25 April 2017 19:59
I am going to believe what the Onan manual says (as reinforced by what I have seen with my own eyes while repairing them) rather than some diagram found on the Internet. In any case I expect that bdub diagram just has L1 and L2 mislabeled on the receptacle; the fact remains that the two hots on the receptacle are bonded and the neutral/ground conductors are bonded. And if the Onan has _not_ been messed with then the double-wire L2 is bonded to the Onan chassis and would serve as what we think of as a neutral/ground; OTOH the single-wire circuit-breakered L1 feeds the bonded "HOT" conductors in the receptacle.

> Repetition is good for young minds. So here goes again. Whatever comes out of the Onan circuit breaker is hot, and whatever else is left coming out of
> the Onan 120VAC wiring is neutral/ground.

The circuit breaker could be in either leg and be just as effective in interrupting current flow as it is supposed to. It would not be proper to have it that way - but it would work.

> But check with your multimeter before you assume anything.

Agree completely and the test is simple: check voltage between a bare metal spot on the generator chassis and each output wire. If the reading is 0VAC between the chassis and the wire then that's your "neutral". If it reads 120VAC then the wire is the "hot".

--Jim
Jim Miller
1977 Eleganza
1977 Royale
Hamilton, OH
I think we need to go with your last sentence. Because between POs and documentation, any way it is, or says it should be, might be wrong.

A PO had removed my Onan and everything attached to it. So I had to put it all back. I had to figure out the hot and neutral/ground because of that GMC documentation conflict. It turned out the wires that reached the splice box were backwards from the Onan documentation. What should have been the single larger gauge "hot" wire was two smaller gauge wires coming off the breaker and the two smaller wires were connected to a single larger gauge wire at a point close to the end bell. I suspect PO involvement in this case. Didn't matter. I have a multimeter and know how to use it. I guess a PO wanted two hot wires to connect one each to the black and red wires going to the 50A receptacle from the splice box. OCD maybe. I dunno. I wired it with all the hots connected to each other and all the grounds/neutrals connected to each other in the splice/junction box. Works like the factory intended it.
 
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