Motorhome electrical problem

We have a 2004 HR Neptune and are having an electrical problem. I have power to 2 outlets in bedroom and no working outlets in the rest of the coach. One mechanic said it would be a automatic transfer switch not working. When I turn the inverter on everything in the coach works. Has anyone had this problem or might know what the problem could be?

First thing I would check is that in your breaker box there is probably a breaker labeled "inverter".  Make sure that it didn't accidentally trip; if it had, the symptoms would be exactly what you are describing.  Your inverter has an internal transfer switch (separate from the MH's own transfer switch) that permits shore power to flow through regardless of whether or not the inverter itself is"ON".  But power won't flow through if the breaker supplying power to the inverter is OFF.

The inverter may also have its own internal breakers that may have tripped.

ajchamblee said:

We have a 2004 HR Neptune and are having an electrical problem. I have power to 2 outlets in bedroom and no working outlets in the rest of the coach. One mechanic said it would be a automatic transfer switch not working. When I turn the inverter on everything in the coach works. Has anyone had this problem or might know what the problem could be?

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Your saying that you have two 120V outlets that are working and no other 120V outlets work on shore power  but when you activate the inverter they produce 120V ? Correct? ?  on a side note if the transfer switch did not work you would have no 120V power anywhere when on SP

boatbuilder said:

The inverter may also have its own internal breakers that may have tripped.

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then you would not have power to those circuts when on invertion which he says work fine while on invertion

buchanan said:

  on a side note if the transfer switch did not work you would have no 120V power anywhere when on SP

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With all due respect  that's not true.  Large inverter/chargers like the Magnum MS2800 we have and the Xantrex Freedom we had before it, contain internal transfer switches that are totally separate from the MH's main transfer switch.  The main switch provides power to the inverter through a breaker and the inverter passes that power through to the outlets and lights via another transfer switch.  It is quite possible for the inverter's transfer switch to stick so the only way to get power is to actually use the inverter to take power from the batteries.

buchanan said:

then you would not have power to those circuts when on invertion which he says work fine while on invertion

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Inverter/chargers are usually wired with a breaker on the main panel that protects the inverter circuit.  For example, in our MH the incoming breaker is 30A.  Then there usually are one or more breakers in a subpanel following the inverter.  In our case we have a 15A and a 20A circuit in the subpanel.  The outlets and lights in the RV are fed off of the subpanel.

If the subpanel breakers are tripped there would be no power to the outlets involved regardless of whether or not the inverter was on or off.  However, if the "incoming" breaker is tripped, there would be power to the outlets if the inverter is on since it would be "inverting" the power from the batteries and doing the job it is designed to do.

You are correct, docj.

Lots of great info so it sounds like it's probably not the transfer switch. I've tripped all the breakers on the main panel and that didn't work as well as the 2 breakers on the inverter. Where would the "subpanel following the inverter" be located? I'm not familiar with a subpanel.
Thanks again for all the info!

Andy

The transfer switch in the inverter may be not switching to shore power when present.  The outlets that do work without the inverter are powered directly from the load center panel, while the rest are powered through/by the inverter.  You may not have an inverter sub-panel, the outlets may be wired directly from the inverter as mine are.

Ned said:

  You may not have an inverter sub-panel, the outlets may be wired directly from the inverter as mine are.

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My Xantrex was like that; most of the Magnums don't come with built-in breakers.  Technically, the ones on the inverter are a subpanel (even if not physically separate) because they follow another breaker (the one ahead of the inverter).

ajchamblee said:

Lots of great info so it sounds like it's probably not the transfer switch. I've tripped all the breakers on the main panel and that didn't work as well as the 2 breakers on the inverter. Where would the "subpanel following the inverter" be located? I'm not familiar with a subpanel.
Thanks again for all the info!

Andy

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If all the breakers are ON then, unfortunately, the problem is likely to be the internal transfer switch.

Does your inverter have a remote panel where you can see if it is seeing power?  Can you tell if the charger side is working?  What I'm wondering is if it is possible for it to operate so it's inverting but the charger is also charging the batteries back up.  That would be like having an inverter that didn't have a transfer switch.  If that were the case, at least you'd be able to operate.  Otherwise the batteries will simply drain after a few hours of providing power.

If Ned's online he might have some idea as to whether or not this might work.

I know the charger is not working. The batteries ran down and I had to put the charger on them.

Andy

docj said:

My Xantrex was like that; most of the Magnums don't come with built-in breakers.  Technically, the ones on the inverter are a subpanel (even if not physically separate) because they follow another breaker (the one ahead of the inverter).

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If those breakers were tripped, then the outlets would not work on either shore power or inverter.  We have 2 breakers on our inverter for the dual outputs, but I wouldn't call it a subpanel.

Since the charger isn't working either, I suspect there is a break in the wiring from the load center panel and the inverter/charger.  That would explain all your symptoms.  Have you checked the inverter/charger breaker in the load center?  Check for 120VAC there, and if present, then see if it's present at the input to the inverter/charger.  That will tell you if the problem is in the inverter/charger or in the wiring.

When I turn the inverter on everything in the coach works. Has anyone had this problem or might know what the problem could be?

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This quote from the OP original message seems to tell me that the main (or "generator") ATS itself may be the real problem here. This is further bolstered by his statement

I know the charger is not working.

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here.

It would seem that no power or only partial power is getting into the coach perhaps because of some dirty/burned or open ATS contacts. It's voltmeter time!!!

Alfa38User said:

It would seem that no power or only partial power is getting into the coach perhaps because of some dirty/burned or open ATS contacts. It's voltmeter time!!!

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One possibility that we've all overlooked is that the main ATS is only functioning on one leg of the 50A hookup and it happens not to be the side that the inverter is connected to.  That would produce the same set of symptoms I think.

Since we don't know which Inverter/charger the OP has, everything here is conjecture.  The main transfer switch would seem to be working if the OP has power to some outlets on shore power.

My guess is that the problem lies in the transfer switch within the the I/C (or between the main panel and the ac input to the I/C transfer switch, as Ned said).  This could/would cause both the "charger doesn't work" and the "no power at outlets beyond the Inverter" conditions when the inverter is not on.

I know that Xantrex transfer switches can have some confusing symptoms in certain failure modes.

NOTE: I was assuming the Neptune was a 30amp coach. (Just discovered that it is NOT....) 

Some info the O/P posted in his original post is important.. He said if he turns on the inverter power to all outlets.. This means any breakers on the inverter, if any, or in a sub panel, if any are functional and are SET not Tripped and thus we can eliminate those.

He said the batteries are NOT charging.. On this type of inverter this is often a function of a different module inside the same box

This inverter contains (usually) 4 main modules

The Inverter (Working)
The charger (Not working)
The transfer switch (Unknown)
and a control board (Unknown)

Here is how it functions:  120 volt power comes from the main breaker panel, usually a 30 amp breaker, (Could be a 20) to the inverter.. The control board senses this and tells the transfer switch to go to PASS THROUGH mode, it also reads the battery voltage and commands the charger module (This board controls ALL functions)

My guess is that 120 volts is not getting to the inverter.. Suspects include...

IF the rig is 50 amp the master automatic generator transfer switch (IF you have two air conditioners do they both work)

The breaker for the inverter

The connections on the wires to the inverter (PRIME SUSPECT) both ends

And finally the inverter's control board and transfer switches.

But my guess is a bad connection on the inverter's "Shore power" side (120 volt wires to the inverter)  Check them First.

ajchamblee said:

We have a 2004 HR Neptune and are having an electrical problem. I have power to 2 outlets in bedroom and no working outlets in the rest of the coach. One mechanic said it would be a automatic transfer switch not working. When I turn the inverter on everything in the coach works. Has anyone had this problem or might know what the problem could be?

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I think that one leg of the 50amp service not working. I had a friends do that and some of his outlets did not work and his charger section of  inverter also did not work
That's most likely why everyone works(outlets) when on inverter  although its not always commen that all outlets go through inverter