Onan 7000 help

[orfunauto/Darrell]

Hello all,
I have an Onan 7000.  Yesterday I was on shore power and switched over to the generator to drive the bus over to my friend's shop to use his pit and check everything over before we take off on Tuesday for west central Minnesota.  I pulled over the pit and was getting out of the bus when I heard an arching sound coming from my front Coleman air.  It pulled the generator down to where it stopped the engine.  I shut everything down including the 3K Pro-sine.  When I got home, I hooked back up to shore power.  Everything worked except the a/c of course!  I had another friend come over and we found a blown capacitor/relay on the a/c unit.   That won't be a problem, he will have one on Monday morning.  I then started the generator and disconnected the shore power.  It would not switch over.  Checking the generator, I found one of the breakers on the generator tripped - probably due to the a/c malfunction.  After resetting, I shut it down, then restarted it.  Still not generating...  I then checked the 10amp? fuse on the generator, it was good.  I opened up the LYGHT (brand name) transfer switch and check the terminals that the wires from the generator are hooked to and found no current on either side.  Soooo... now I'm assuming there is a problem with the generator.  Any suggestions as to where to look next would be greatly appreciated.

[Nick Badame Refrig/ACC]

Hi Orfunauto,

Before you go deep into the gen set, please check the contacts on your transfer switch. Open it up and let us know if there

is any burn marks at the contactors. If so, this may have caused a "nutral bond" or worse, dead short and feed back into the genset.

I'm asking you to check that first because of the blown capacitor in your a/c.  Capacitors only blow apart when you have a voltage problem.

Good Luck
Nick-

[orfunauto/Darrell]

Thanks Nick.  I'll check it out in the daylight in the morning.  My first thought is that the switch looked as though it would not come apart.  But I'll take a closer look at it in the morning.  Thanks again, I'll let you know what I find.
Darrell

[TomC]

Curious to me why your generator stalled out.  I would think the circuit breakers should have tripped before the gen had overloaded.  Maybe I'm missing something here.  Good Luck, TomC

[belfert]

My friends and I managed to stall the Onan Microquiet 4000 in my travel trailer once.  Somebody decided to use the microwave while we had the frig on AC and the roof A/C running at the same time.  Interesting thing is the main 30 amp breaker tripped at the same as nothing worked until the breaker was turned back on.

[TomC]

Now that I remember, my 6.5 Onan in my truck stalled many times.  The stupid thing had to be tuned exactly right to not stall-which is hard when you're driving and in different altitudes every night.  If this was a Diesel, though, I would still question why it stalled.  Good Luck, TomC

[prevost82]

Not to high-jack this thread but what would be the best way to hook up an idiot light in the drivers area so I know that the gen is still running when I'm running down the road with it running.
Ron

[Nick Badame Refrig/ACC]

Not to high-jack this thread but what would be the best way to hook up an idiot light in the drivers area so I know that the gen is still running when I'm running down the road with it running.
Ron

Hi Ron,
You can tie in a second remote panel in your drivers area so you can monitor and control your gen.
It's fairly easy to do. It would be like having a mirror panel.
Nick-

[orfunauto/Darrell]

This had to be an on-going problem that the P.O. didn't divulge when I bought the MCI8 from him in April.  I have had a problem with the generator not switching over when I disconnected the shore power.  The Onan only had 71 hours on it when I bought the coach.  When I took the panel loose from the generator to check the back side of the circuit breakers, I had current at both sides of the breakers....  I said OK to myself and proceeded to put the cover back in place - I heard a slight sound as though I tripped a switch or something and for grins I checked the breakers again - no current!  There is a ten wire plug behind this panel that noticed bumping about the same time I heard the switch type noise.  So I tugged at each of the wires on both sides and found a wire which pulled out with ease!  Looking closely at the terminal I seen that it was supposed to be a female - but it was squeezed together.  Opened it up slid it back in so it locked - Problem Solved!!  It's a great day!  Do you think that this short may have caused the capacitor/relay to fail?  Just curious....   

[Sam 4106]

Hi orfunauto,
It's good to read that you have solved your generator problem. Hopefully it will be as easy to fix your A/C. I know what a capacitor is and I know what a relay is but I have no idea what a capacitor/relay is. Would you please explain?
Thanks, Sam 4106

[Sam 4106]

Hi Nick,
I read one of your posts on another board this morning which had the following statement in it, "We are pretty good with gen/transfer switch wireing.", so I have a few questions for you about orfunauto's situation.
1. How could he have a "..."nutral bond" or worse, dead short and feed back into the genset." since he was only on gen power at the time of the incident of his A/C "arching" and his generator died?
2. Even if he had  both shore and genset power to the transfer switch, at the time of the incident, how could he have gotten power feeding back into the genset? To my knowledge, the transfer switch gives priority to one source and the other source is locked out.
3. Even if one set of contacts welds themselves together,as you imply when you ask him to look for burned contacts, how could the other set close, due to the lockout incorporated into the transfer switch?
4. Are you sure you understand what a "nutral bond" is?
These questions are based on my understanding of how my Magnetek Model ATS 100 works. If you have a different brand or model it would be interesting to know how any of the situations that I have asked about can happen.
Thanks, Sam 4106

[Nick Badame Refrig/ACC]

Hi Sam,

This happened to me.. My transfer switch has two sets of contactors inside, one contactor grabs, and one releases depending on which power source

you choose. Now picture this, one pole of a contactor welds itself from a pitted or a bad surface, then when I switched to my generator it back fed

current to my 50 amp shore plug that just happened to be toutching the body of my bus in the storage compartment. Everything went haywire....

The gen breaker tripped, my main panel breaker tripped, as well as sending my Xantrax RS300 into lock-up. The code that came up after resetting the

RS300 was "nutral bonding incorrect". Whoda thought.. Hope I said this clear enough.

Replaced my transfer switch and all is well now.

Nick-

[orfunauto/Darrell]

OK, I'll try to explain in my layman's opinion why I called it a capacitor/relay. 

Nick, please correct anything I say, so no one is misled by my amateur explanation. 

I have in front of me a capacitor and the remains of a relay.  The relay is labeled: WSX-5ACM motor starter relay.  It was attached to the capacitor by two female spades.  The capacitor is labeled: Mallory 88-108MFD, 165VAC.  From what I was told by the refrigeration man, (non-Maytag)  is that the relay overheated because of low voltage(?) being supplied by the generator.  Hope this gives you the right explanation.       

[Nick Badame Refrig/ACC]

Oh Sam,

Syl and I have traced the spike problem of his gen set to a faulty voltage regulator. We set up an isolated test on the genset, we loaded with about 20 amps draw

and the gen held at 120v. The spike happened briefly, a few seconds, then went back to normal. The gen sounded to drag down, and a small light bulb went

very bright. Kinda like a very large load on the gen. The only thing that can cause that is the voltage regulator.

Nick-

[Nick Badame Refrig/ACC]

OK, I'll try to explain in my layman's opinion why I called it a capacitor/relay. 

Nick, please correct anything I say, so no one is misled by my amateur explanation. 

I have in front of me a capacitor and the remains of a relay.  The relay is labeled: WSX-5ACM motor starter relay.  It was attached to the capacitor by two female spades.  The capacitor is labeled: Mallory 88-108MFD, 165VAC.  From what I was told by the refrigeration man, (non-Maytag)  is that the relay overheated because of low voltage(?) being supplied by the generator.  Hope this gives you the right explanation.       

The relay will fail when the compressor is trying to draw the amount of current that it is lacking from the gen set. The compressor will then get very hot, and cause the relay to either melt down or burn a wire off. The capacitor is some what flexible, either the capacitor will "dead short" or the internal connections will "open" no pass through. When a capacitor explodes, it's caused by over voltage or the relay can short to ground causing the same.

Hope this helps
Nick-