Electrical Gremlins

[Mike.Way]

This is such a great resource, I feel like I need to regularly exercise it's members.

We have a '98 Marquis with a Prosine 2000 watt inverter. After 12 years we have collected our share of gremlins.  Here are the current issues.  I have no 110 in about 60% of the plugs in the coach.  When on batteries, with the inverter on, I have NO 110 at all. There are 4 GFCI plugs in the coach, 2 in the bay, 1 in the bathroom and 1 in the living room.  One of the 2 bay GFCI plugs seems to work okay and may actually allow the 3 or 4 plugs that do work to function.  FWIW, the other 3 GFCIs have been replaced within the last week.  Several other circuits work OK on 110; fridge, W/D, electric water heater, etc.  Seem to have OK power through the breakers.

Even when the inverter "shows OK" on the board and I plug in to 110, it goes to fault.

Am I missing something?  I have had to reset power to remove the inverter faults several times.  The voltage difference between house and chassis batteries is insignificant.  The solar keeps them up well and the rebuilt alternator (see earlier thread) charges well, however with the current issues it won't charge any other way.

Any ideas?  George Harwell helped me go through the standard checks last week at "Beavers of the Night Sky".  Thanks George.  He is as stumped as I am.

Thanks

Mike

[Edward Buker]

Mike,

It would be nice if someone had a schematic of the Marquis and could get it posted. That would help us all. Regarding your problem. I am a new owner of a 2002 Marquis in the last year and I cetainly do not know everything about the wiring but see if this helps. My assumption is that you have and know how to use an AC voltmeter, and that you are knowledgeable regarding the safety issues of taking these measurements. If not find someone who is and can help you out.

The main cord feeds a generator transfer switch, (grey box in the bay near inverter) mine is on the ceiling of the bay. With power on you should have two legs of a relay with 120v coming in and going out. Mine buzzes because the fools at Monaco used AC relays coils, that should help locate it if yours is the same. (DC coils are near silent and would have been more suitable) There are red, white and black wires feeding the relays. Measure red to white and black to white. If you do not have 120V on these wires you could have a cord problem or a transfer switch problem. If 120v is not coming into the relay it is a problem with the cord or wiring coming to this relay. If 120v is coming into the relay but not going out on one side it can be the relay contacts. Because at least one side is working you do not have a coil problem or a board problem. If both sides were not working you would have no AC in the coach.

From there I believe that the power feeds the rear panel where you should be able to see 120v on both busses of the breaker panel to neutral or ground. If that is O.K. then there is a feed to the inverter which contains a 30 amp transfer switch. This transfer switch either uses the incoming AC when available or generates AC via the inverter circuit and sends that output into a small greay breaker box also located in the bay. Mine is on the ceiling of the bay. My guess is that the inverter and the transfer switch is involved with your problem and that no ac 120V is being fed to the small bay AC breaker box. If it is labeled, you could see if the AC circuits that are not seeing 120V line up with the label. With the cover off this box you should be able to measure if 120V is being fed in. The inverter may have its own AC breaker usually a small red pushbutton on this kind of electronice that could need to be reset. Someone may be able to comment....

Without a schematic I am giving you my understanding of what I have reasoned out as to how the AC system works. It should be close. You can start looking where you like, I usually start just before where I think the problem is and verify that the voltages are as they should be and then work forward from there.

GFI outlets can feed other outets but I believe that you have replaced and reset those and it seems like too many locations are not working to be one GFI outlet feeding your problam...Good luck on your hunt.
 
Regards Ed

[Gerald Farris]

Mike,
From your description, it sounds like you have an inverter failure. Check the 110V feed into the inverter. If you have 110V coming into the inverter and no 110V output from the inverter when on shore power, the inverter is not functioning properly.

This will account for no 110V power on about 60% of your base plugs in the coach since the 110V current to any base plug that receives 110V power from the inverter when on batteries, has it's shore power feed routed through the inverter. The circuits that you say are working OK on shore power do not run through the inverter, since the inverter does not power them when on batteries.

A defective inverter will also account for no 110V  when on batteries. You may be able to reset the inverter, but it sounds like the internal transfer switch has failed, and it may or may not be repairable.

Gerald

[Mike.Way]

After considering Gerald's answer and talking to Roy M on Saturday morning,my 1st thoughts were verified.  I just ordered a new inverter.  I will let you know about the installation.  Thanks again.

MIke

[Mike.Way]

As an update.  

I ordered and have received a Magnum 2012 inverter/charger.  Monday was spent removing the Prosine.  It was mounted on a welded platform of 1/8 angle and had several inches of overhead.  The Magnum of course did not fit the platform, but I acquired 2 pieces of 1/8 by 1 1/4 steel; mounted it to the inverter and then bolted it all to the old frame.  Pretty solid.

There are some wiring differences.  The prosine had three connection in and a 3 connection out.  Beaver had doubled the wires from the out connections; 2 circuits.  The magnum has neutral and 2 hot in and a neutral and 2 hot connection out.  The ground is common. The incoming cable in was modified by connecting 2 jumpers to the incoming hot and feeding both hots.  That was from the Magnum manual.

So now the AC is connected.  Tomorrow, the 12 volt gets connected and it all gets tested.  

I'll keep you posted.

Mike

[Bruce Benson]

You did a smart thing, in my mind, getting away from the Prosine.  Magnum has to be better than Xantrex!    

[Mike.Way]

Hey all,

as George H. reminded me I forgot the final bits.  All is well once again.  The Magnum electronics do a great job.  Everything seems to work as it should.

A couple of things I am very happy about;  the default is not to turn on everything when you plug in, the Prosine defaulted to all on and often would pop a fuse before I could get to it.  Second, I like being able to limit the amps used for charging; I can now charge the batteries from a single outlet on a 15amp house hold circuit.  

On a side note, I also changed out all the GFCI devices in the coach.  They now have pilot lights and are I hope 12 years newer technology.

Thanks again for the comments and phone calls,

Mike

[Marty and Suzie Schenck]

Bruce, This is just a question. Exactly why do you think getting rid of the Prosine a smart idea? I and my neighbor both have 2002 Beavers with Prosines and have not had problems with them. Marty

[Roy Mueller]

Prosine is good unit.The problem comes when it you need to get it repaired. The rebuilders tell me

Roy M