Generator Issue

[happycamper1]

I have a 2006 Limited and discovered a problem the other day that I can't find a solution for.
I start my generator and after a few minutes it slows down as normal when it delivers 120v to the coach. My issue, the power does not transfer to the coach. All outlets and appliances stay dead, however, both my roof airs work so I know the generator is producing electricity.
Now, I plug my rig into shore power, 50 amp, and everything works. I have researched every possible topic on this forum but can't find a potential solution. Any thoughts?

[twinboat]

Power transfers to the coach because you say both air conditioners work.

Do you have a load sheading system ? The generator may not have enough output to run both air conditioned and other things.

How many watts is the generator ? Shore power is 12,000 watts. Some generators are less then that.


Did you try outlets with the air conditioners off ?

[happycamper1]

The generator is an Onan Quiet Diesel 7500.
I tried the outlets, microwave, etc without the air running, no power.
I tried the circuit breaker on the generator. When I turned it off the air died. Even tied the coach circuit breakers even though the outlets and appliances work on 110.
I am at a loss.

[Purple Frog]

Voltage transfer switch may be only switching one of the 110v legs. It should switch both 110v legs during the switch from shore to genset.
They are known to fail. Lots of threads out here on the subject.

You can check it with a volt meter after you find it. (mine is under the bed)
If you take the cover off you can check both in and out voltages.

Some folks suggest first tapping it with a hammer.

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[okcnewbie]

I suppose the onan is 220?
It appears that one of the Hot leads isn't making it to the distribution panel.
Verify that the genset has the correct output and than follow through the transfer switch to the DP.

[twinboat]

Do you have 3 air conditioners ?

If not, then each one should be on each incoming leg. That would rule out a transfer switch issue.

If they are both on one leg, then a wiring issue at the generator and or auto transfer switch is possable.

[c_oneil]

There is a junction box behind the generator on the underneath side of the coach floor that has a splice between the generator conduit cables and the rubber insulated cable heading to the transfer switch. There is a history of bad/loose connections there that could cause you to loose one leg. Some say the wirenuts used by WRV were inadequate. Really good idea to check it out for safety reasons.

[bcruzen]

I have experienced the following with mine:

1) The junction box that has been previously mentioned has been an issue for me, the old wire nuts worked their way lose and the transfer switch was not getting power.
2) Sometimes if you have had the coach's power disconnect switches off for a while or the batteries have drained, the inverter will will need to be reset on the inverter unit itself, hit the reset and power is restored to the rest of the unit. I suspect this is most likely your issues as the big power items are working while the rest of the lower power/inverter powered items are not.

[DrDaveMA]

The other thing you should look at is the ATS, it might not be transferring both 110 legs.

[DrDaveMA]

Only some of the outlets in the coach are on the inverter, so if it was not working those inverter powered outlets would not work all of the time, shore power or genny. When you say “none of the outlets and appliances work” are you sure ALL of the outlets don’t work, or could some of them be operational?

[whalepirot]

Outlet loss can be caused by a GFI trip. Ours is under the mirror above the bath sink. Press trip, then reset buttons, just like at home.

[Alpine06]

Hi Happycamper1,
upfront I like to say that I do not have a solution but
here are a couple of clarifications for some of the posts above:
A) we have a 110V coach NOT 220V. Both phases L1 & L2 are syncronous and therefore the potential(voltage) between them is 0 and not 220V.

B) IF both AC's are working then you have both "legs" because of the high current demand they are not on the same "leg" (phase to be correct... meaning they are not on the same 110V breaker in your fuse box).

C) The transfer switch has 2 relays. Two in and one out. They work like a seesaw- only one side can physically be connected. If you open the ATS then you will find 2 60A Cuttler Hammer relays (used on 2006). So for the line out it makes no difference if the power is from shore or the generator ... all the same "kool aid" for the coach. In other words past the ATS the coach does not know where the power comes from.

So this leads us to:
your fuse box. You already know the big breakers are working as the AC's are running. However I suspect there is something wrong with one of the smaller breakers. Cycle every one of them off and back on even if they are not tripped. Again that makes not complete sense as you have them working on sore power.
And yes you will find some of your outlets to be powered by the inverter.

Your description is a bit like: My coach steers to the left and right in first gear but only to the left in second .... I guess while possible everybody will raise the eyebrows.
Do you have a surge guard?

One other explanation is that your coach has been rewired so both AC's work off of one leg so the Generator part is only providing that leg and not the other - very unlikely but a possibility. Please check "B" above they are of 2 separate breakers - Yes?
You will need to measure power at the ATS but I do not recommend you do that unless you are safe using a voltmeter on a life circuit.

Let us know - I am very curious to the root cause of this one.
Joerg

[twinboat]

If you plug into 50 amp shore power, it is delivering 240 volts, thru all of your equipment up to your main, 50 amp, double circuit breaker. If you measure between each breaker, you will read 240 volts.

50 amp shore power has 2 hot legs, a single neutral and a safety ground. You can't send double the current thru a single neutral.
https://www.rvtechmag.com/electrical/chapter3.php

Thats how it works.

Your generator may be supplying 120 volts on each leg but that's carried thru 2 hots and 2 neutral wires to the generator connection of the auto transfer switch.

[DrDaveMA]

The OP has not posted since 7/25, we need to hear from him before we can help him.