Help solve my electrical mystery!

[RufussSewell]

Ok, I plan on adding some photos and videos to this thread.

4 different RV service shops have failed me. I have no clue what to do next. I really can't keep spending thousands of dollars at RV shops to have them fail but still charge full price.

My problems started in December. On a long winter drive from Michigan to California the lights started to flicker about once per minute. Strange. This also meant no A/C which was fine in the winter but is becoming a health hazard now that summer is near.

When we got to CA I double checked with shore power and everything was fine. Also on inverter power everything was fine. But A/C can't run on the inverter and I'm not usually plugged in. It was only on gen power that there was a problem. But I do a lot of boondocking so I need gen power for A/C.

I checked several spots and noticed that the AC power would slump from 118 or so down to 106 - 109 during the flicker. This happened at the gen, at the transfer switch, at the inverter etc. what is making the AC slump?!?

The strange thing is that there is one outlet that is fine with gen power. I have an extention cord running to it so that I can use the coffee maker or microwave. ONLY this one outlet is not connected through the inverter. If I disconnect the inverter completely this one outlet still works. Also if the inverter is on but the gen is off it doesn't work. So I think it is directly connected to the gen.

At this point I replaced all 6 batteries because they were old and dying too quickly. I also serviced the Onan QD 7500 genset. When I was having the batteries replaced I paid for service #1 to check for the flicker.

#1 service Sacramento, CA: Did a thorough electrical inspection and determined that the inverter was bad. He said it would be $3000 to replace. He was right that the charger side wasn't charging so I figured it was bad. I'm usually on the road so my alternator had been charging the batteries so it wasn't a problem, but I figured it may mean other problems so I had the inverter repaired.

Luckily the guys at Batteries+ fixed my inverter for $14! I couldn't be happier. They checked every circuit, ran a load etc. I reinstalled the inverter and it did charge the batteries now. It also inverted fine AND passed shore power through to the panels. Still the gen power flickered.

#2 service San Jose, CA: I finally said have at it! I need my A/C so do what it takes to fix the problem. These guys spent all day, fixed some other issues and charged me $1400 to tell me my inverter was bad. I explained to them that it didn't make any sense because Batteries plus thoroughly checked every circuit, and it works fine on shore power. Why would there be any difference from gen power and shore power?!? I figured they were wrong and it had to be the gen or transfer switch. $1400 down the toilet.

My gut said it couldn't be the gen since the one outlet that was directly connected to the gen always worked perfectly. It had to be something in between.

#3 service Cummins Sacramento: Despite my gut feeling I figured it was best to have the gen checked. So I had Cummins fully test the unit. They ran it with a high load for an hour and said it was working fine. There wasn't any reason the gen should be causing a flicker since they isolated it from my coach. $285 and sent me on my way.

#4 service at a different shop in Sacramento... who knows might as well get a 4th opinion. They quoted me $100 so why not?!? These guys ran tons of tests with all the info I had gathered up to this point. They tested on shore power, they tested the transfer switch, and determined... It's a bad inverter. Doh!!! $100 down the toilet. I argued with them some more because it literally makes no sense that the inverter would work perfectly on shore power but not on gen power. The power comes in on the same cable so it couldn't possibly have anything to do with the inverter. They still made me pay the $100 for their failed service.

So they've beaten me down. All 4 places blamed the inverter. So I bought a brand new shiny Xantrex 2000 watt inverter. It's very nice and pretty. But the lights still flicker and A/C turns on/off with a loud thud once per minute. The same as before with my old inverter.

Here's what I know:

*On shore power everything is fine.

*On inverter power everything is fine.

*Gen power flickers but ONLY on the circuit connected to the inverter.

*The wall outlet connected directly to the gen does not flicker.

*When the gen is isolated there is no power slump. So it's not the gen.

*With a brand new inverter I have the same issues. So it's not the inverter.

*Whenever the power slumps the inverter switches on. This is what is causing the flicker.

*Im looking specifically for the cause of the power slump which is making the inverter switch over for second causing the flicker.

Is there any electrician out there who only charges you if they actually fix the problem?!?!?

I refuse to pay again for failed service.

Thanks for hearing my rant, haha. Please help if you can I'm getting broke and desperate because of this. Thanks!!!!

[Skip426]

OK, you've got me interested, I can't help, but having read up on your adventure so far I would like to see if you get answers and have your problem resolved, so I'll tag along , if you don't mind.
A quick question in the Sacramento #1 was $3000 to replace the inverter a typo ?

[DSL417]

Inverters are expensive...and I'll use this to follow your post. Have a fellow Entegra owner I'm going to PM who used to have a Beaver and is pretty knowledgable about coaches...I'm going to pass you post on to him in a PM and see if he has any ideas. I would also suggest, if there is a beaver forum here, maybe report this there...or whatever company bought the Beaver assets...if there is such a thing. Good luck.

[MJ56]

I feel your pain, I have been doing some electrical troubleshooting also.
My coaches do not have inverters, so I haven't dealt with the inner workings.
I first suspected the generator, having learned that the windings can deteriorate and affect the output.
I think you correctly have eliminated the gen and inverter. One test I would want to try is running A/C directly from gen.

I do know that continuous duty relays can fail or cause intermittent problems due to bad contacts or weak coils.
If all parts of the inverter and gen are verified working, I would guess it is something in the transfer switch is causing the voltage drop or cycling the inverter on/off. I don't know much about transfer switches either, but I would look for whatever is involved in sensing voltages and switching sources.

My mother always said, you will find it in the last place you look.

[stink]

Do you have a 50/30/20 ac service into the coach? is this controlled by an Intelliteck controller? This controller on my coach is built into the transfer switch for genny power. Mine was acting funny, not like yours but I found a loose connection at the transfer switch. The wires from the genny had loosend and corroded causing a low voltage problem. Might check there. I would also check wiring from genny to fuse panel if you don't have the intellitech box.

[DSL417]

Gotta say...it sounds like a transfer switch issue to me as well, but I didn't know what kind of transfer switches were in use 15 years ago.

[RufussSewell]

This is the transfer switch.

[RufussSewell]

All three RV service centers tested the transfer switch. But they concluded it was the inverter and were wrong about that so...

[MRUSA14]

Rufus, you have done good work to isolate the problem. One thing is missing: Does the A/C work reliably when on shore power? If not, it could be a problem in the A/C or the A/C circuit breakers.

If the A/C is good on shore power, then based on what you report I think the problem has to be either in the generator or in the connection between the generator and the inverter. Although you had the generator tested, I wonder if there could be an intermittent problem in the generator output circuit going to the inverter. Also, it could be bad connections between gen and inverter. I would carefully examine, clean and tighten the connections at the generator side and at the inverter side. The other possibility is a bad cable between the generator and the inverter. If possible, I would temporarily run a new cable between them. If the problem is in the cable this will make it go away and you will have discovered where the problem really is.

Although your problem is not particularly Beaver specific, The folks at Beaver Coach Sales in Bend Oregon are Beaver experts. Call them, maybe they have seen this problem before.

Good luck, I know this is a nasty problem but the above steps should lead to a solution..

[RufussSewell]

Yes, the air conditioner runs fine on shore power. There is a transfer switch (pictured above) between the gen and inverter.

I'm pretty sure the problem is between those two somewhere. The connections at the inverter, transfer switch and gen have all been cleaned and tightened. But I'm not sure if there are other components like a breaker panel in there somewhere. I imagine the breaker panel is after the output of the inverter and before the outlets and appliances.

All of the wiring is pretty well hidden away. I suppose I could run a wire directly from the gen to the inverter to cut out the transfer switch and anything else that may be in there.

[nothermark]

I am confused. If you have an inverter feeding some of the AC outlets all the time it is always drawing off the battery bank and so should be immune to generator fluctuations. In essence it becomes an uninterruptible power supply. If that line fluctuates it is the line, load, or inverter. A fluctuating load can cause a fluctuating inverter or generator output as they adjust to the changed current draw. It is the same as the lights dimming as the compressor starts.

If the AC really is switched from inverter to generator and one circuit does not fluctuate but the rest do it sounds like a problem with the distribution buss in the breaker panel.

Given a 50A 230V service you can have a problem with one leg of the 115V service but not the other. 230VAC is a center tapped transformer with the center tap grounded and the neutral return. That provides two paths for 115VAC to neutral and one path for 230VAC with no neutral used for high draw loads. Because there are two 115VAC distribution paths you can have a problem on one but not the other.

Given that there have been several fingers in the pie I assume (dangerous) that they checked for loose wiring nuts/screws. That has me thinking I would be working my way through the electrical system with a smallish plastic faced hammer while monitoring or having someone monitor whatever you were looking at that showed the line voltage dips. I'd tap hard enough to know it had been tapped but not so hard I was making dents or breaking things. If tapping something shows the flicker then you have your culprit.

[vraines]

The voltage "slump" to 106-109 volts indicates to me that the generator is attempting to go off-line. Get someone with a "Fluke" voltmeter or similar meter and verify it is consistently producing 60 Hz. That voltage drop might be a poor attempt to regulate cycles. I would think that the transfer switch either is in contact or not in contact. The voltage drop seems to exclude the transfer switch. Sorry about your challenges.

["007"]

In the load center or breaker panel you have a circuit breaker feeding your inverter did they check that wiring for outlet.
RV outlets can be a problem also with poor crimp connections not like your house outlets with screw connections.
Do you have a surge protector and are all connections in good and tight.
AC's should work out of load center because of their high current draw when compressor starts.
Have you looked through this sticky above for info.

[pcurt23]

I have a Fleetwood so the circuit setup is probably not the same but we know that the inverter function is to provide AC power from the house batteries. I do not think that there is any power through the inverter /charger going to the air conditioners. You can turn off the inverter while on shore power or gen power and all systems will operate. I have one circuit that powers the front of the coach that is tied to a breaker in the inverter.
One odd thought came to me. It is possible that the charging portion of the inverter/charger is sucking enough power from the gen set to cause the rest of the system to droop?
The other thought is that an electrical diagram may show which component in the system is energized differently between gen set operation and shore power.
If it were me, I might replace the transfer switches just to eliminate that system.

The other way out there though is that I was have weird electrical issues a while back (not like yours) and I found a broken battery terminal. I did not actually find it the people changing the batteries did.