Okay, I need help in knowing how to go about trouble shooting this problem.

Woke up this morning to find that the power was out and the temperature in the house was about 50 degrees. We got about 4 inches of snow yesterday and the air temperature was 25 this morning. And as things would have it, we have the grandkids this weekend and our granddaughter had a sleep over friend as part of her birthday celebration.

I went out and fired up the generator on the Barth and turned on the two furnaces. Everything worked fine and soon the grandkids had a place to fix breakfast and watch TV. After about two hours about half the coach outlets and appliances quit working. I checked all the circuit breakers and none were tripped. I tripped and reset the main breaker. The Main breaker is a double pole 50A. With a multi-meter I checked for current on the "IN" side of the breaker. 120v on one leg, Nothing on the other leg.

After the power came back on, everything works normally, and I have 120v on the input of BOTH legs.

First assumption- The generator is not supplying 120v to both legs. Why?

HELP

Nick

Nick, there should be some sort of protection at the genset itself (before the main panel)... Either a breaker or a reset.
First I would try that and see if it works.. If not check the power coming "out" of the genset at or even before the protective device, if there is power on only one "leg" at that point then the prob is in the genset itself and you'll have to start checking the schematic and/or test procesures for your particular unit.. If there is power on both legs coming "out" of the genset start checking for loose connections (especially if it is aluminum wire) at all termination points (with the power off of course)..

Nick,

Sadly, I have loads of experience with my Generator when it went on the blink with 85 total hours. Patch gave some good advise on isolating the problem. It may be as simple as the generator fuse/breakers, the regulator, or the gen circuit board.

I ended up replacing the regulator first, and still had just one leg powered. On my Kohler, the generator will shut itself down if it doesn't sense power on both legs, so I was only able to figure it out (the single sided power) after hot-wiring the fuel pump (diesel). I remember we looked at yours and I recall it was a diesel, is that correct? Also, what brand?

I hope you don't end up with the same diagnosis I had as it was the stator ($3000 part!). It was explained to me that there are small wires that come off the windings that corrode and are non-fixable. One of mine rotted through over time.

At least I recall you have yours on a slide. I had many a sore neck reaching up to the top side of the genset with a mirror in one hand and a flashlight in my teeth! I wish you none of that horror

The generator is a PowerTech, 7.5KW unit, powered by a 3 cylinder Kubota diesel. It is on a power slide that will extend it out the front of the coach.

Nick

Nick,

In conversational terms, not electrical engineering terms, the system should work like this.

The diesel engine spins a magnet inside a copper wire winding field. Essentially an electrical generator and an electrical motor are nearly identical with one making electricity from mechanical power and the other making mechanical power from electricity.

Once the raw energy is sent out of the field, a regulator is used to adjust the voltage (110V X 2). So testing at this output will let you know if the generator is producing on both legs of the stator. From there, the power heads to the transfer box which insures that street power and generator power cannot go through to the power distribution panel (breaker box)simultaneously.

So, if you test at each of those places you are very likely to trace the source. Testing on the input and output side of each component will certainly identify the culprit.

quote:

Originally posted by Nick Cagle:
The generator is not supplying 120v to both legs. Why?

My Generator is a Kohler but perhaps yours might be set up a little like mine.

On the generator, there are 2 manual resettable circuit breakers, 1 for each leg. Reset that switch and you should be "Good To Go"

I have had similar problems, but it was the GFCI plug in the bath that controlled the circuit to the kitchen, bath, and exterior plugs. Try resetting the GFCI outlet if all else fails.

quote:

I have had similar problems, but it was the GFCI plug in the bath that controlled the circuit to the kitchen, bath, and exterior plugs. Try resetting the GFCI outlet if all else fails.

The GFCI would only affect anything down-line of the outlet. Nick said he had no power on one line at the power distribution panel. With that in mind, I don't see how it could be the outlet in this case. It is good to remember that a GFCI outlet affects all other outlets ganged to it though.

nick do you have the schematics for your gen or the installation manual?.Remembae mine when I pulled out the gen you can hold a party at the back of the gen you have a fuse or breaker and a on and off switch sitting under and up facing forward they are on the right side and back.if you do not I can email them to you.
lenny

There could also be an issue with the cutover relay (normally connected to the generator). As has been mentioned, there may be a breaker at the genset for each leg.

Got out today to see if I could find the problem. Pulled the cover from the generator control panel and started the generator. Measured 120v output on both legs. Measured both sides of both circuit breakers to check for a bad CB. 120v in and out on both breakers. Went inside coach to automatic transfer switch and measured input on both legs from generator. 120v on one leg, zero on the other. I am now assuming a broken wire under the coach between the generator and automatic transfer switch. The ground has got to dry up some to crawl around looking for it. Will keep you posted.

Nick

Nick, It is VERY rare that a wire would "break"...
In most cases it will be a loose termination point.. When you checked the power did you check at the lug or the wire itself? Is it aluminum wire? First I would suggest tightening the lugs at the generator then at the transfer switch and check the power again, it is more then likely a loose connection...