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Generator Power Problem

We are in Kansas today where it has been very hot. Yesterday as we were traveling thru, our generator started giving us a problem. The generator would have 120V while we were traveling down the road. But when we stopped and cut the coach engine off and had the generator running the voltage dropped to 111. Both AC's were on so we cut one of them off and eventually the volatage raised to 116.
What could cause the generator voltage to drop while we were stopped but it was fine with the coach engine running?

Ben Harris
1999 U320

Re: Generator Power Problem

Reply #1 –
Could be additional inverter loads like the charger, charging batteries for example.
The selected media item is not currently available. Dave Head & Megan Westbrook
Titusville, FL - The Great Outdoors
'98 270 buying this month
Toad is a 2018 F150 XLT

Re: Generator Power Problem

Reply #2 –
We ran down the road for 7-8 hrs so the batteries should be fully charged. Today the genny showed 122 volts but when we parked it went to 117volts,started engine and ran for 15 minutes and the volts ran up to 119. Strange???

Ben Harris
1999 U320






Re: Generator Power Problem

Reply #3 –
I would be thinking about:
1-Is it only voltage or is the frequency down too ?
2-If the frequency is also down, I would be thinking power, such as horsepower as in  fuel filter, and the loading on the generator.
3-If you have no way of checking fequency, you are really guessing.
4-What is normal voltage with both A?C units on + other normal loads ?

Things that drop frequency are load, engine rpm, then you can get into voltage.  like the regulator or loading and other issues, but normal is loading and or dirty fuel filter.

All one can do is guess from a remote position, so I am guessing.

Re: Generator Power Problem

Reply #4 –
These voltage readings are within normal ranges. Not strange and no reason for concern.

Re: Generator Power Problem

Reply #5 –
Is you coach generator wired for 120 or 240? Mine is wired for 240 because the cloths dryer is 240 volts. I only have one ac volt meter on the panel in the coach, when I turn on an appliance on the leg I don't see on the volt meter, the leg I see voltage goes up because the voltage on the other (loaded) leg goes down due to the load. As explained to me by the Power Tec people at Perry last March this is normal as the generator regulator tries to maintain 240 total on both legs.
John Duld
1995 U320C SE 40'

Re: Generator Power Problem

Reply #6 –
Hey John, we have two 120 legs on our coach.

Ben Harris
1999 U320

Re: Generator Power Problem

Reply #7 –
What voltage do you see when you read between the two legs in the circuit breaker box?(left buss to right buss)
John Duld
1995 U320C SE 40'

Re: Generator Power Problem

Reply #8 –
Quote from: John Duld –
Is you coach generator wired for 120 or 240? Mine is wired for 240 because the cloths dryer is 240 volts. I only have one ac volt meter on the panel in the coach, when I turn on an appliance on the leg I don't see on the volt meter, the leg I see voltage goes up because the voltage on the other (loaded) leg goes down due to the load. As explained to me by the Power Tec people at Perry last March this is normal as the generator regulator tries to maintain 240 total on both legs.

John , if you have 240 volt's on each leg, you have a total of 480 volts, I have not seen a coach wired for 480.
The selected media item is not currently available.Bill&Doris 97 U270 36'
University of Parris Island Class of 66
Semper Fi  Build# 5174 MC#17094

Re: Generator Power Problem

Reply #9 –
Maybe I didn't say that correctly. Mine has 120 volts on each leg to neutral and 240 when I measure from one leg to the other leg(buss bar to buss bar in the circuit breaker box) either plugged into 50 amp service or the generator running. My generator is wired for 240 service so I can run the cloths dryer when on generator power as it is a 240 volt dryer. Power Tec assures me that as mine is wired for 240 volts, when I load one leg the voltage on that leg will go down do the load and the other leg will go up as the voltage regulator will try to maintain 240 volts across the two legs. So while I would like to see 120 volts on the volt meter in the coach it isn't going to do that. Not exactly what I want to see but they assured me that's the way it is.
John Duld
1995 U320C SE 40'

Re: Generator Power Problem

Reply #10 –
I wanted to give an update on my Generator erratic voltage problem. I finally found the problem yesterday after it finally quit putting out electricity. I was pulling all connections to check them and a wire fell off in my hand. I put a new spade end on it and the generator is purring like a kitten, no more voltage problems. It is running a steady 118 volts with or without load.
I think the bumpy Alaskan highway broke my wire. Thanks for all the input.

Ben Harris
1999 U320

Re: Generator Power Problem

Reply #11 –
Ben, sorry I should have thought of that.  When my Kubota was acting up I found a loose wire connector in the control box also.  Glad you got it fixed.
Gary B