Generator voltage fluctuating

[RangerMike175]

I have a Coleman Powermate 7000 Commercial that's putting off fluctuating voltage. I've never seen this before. It does it with and without a load. I put a 1500w heater on high and a small oscillating fan on high at the same time and had the same results. I've uploaded a video of the symptoms to Dropbox for your viewing pleasure.

https://www.dropbox.com/s/te8gfu0b0fa9c7j/Video Jun 20, 5 50 26 PM.mov?dl=0

Please help.

 

[GoldDigger]

Is the speed fluctuating too, or just the voltage?

If the speed is holding steady as the voltage jumps, it is most likely a component or connection in the Automatic Voltage Regulator circuit.
Beyond that, I would defer to someone who is familiar with that brand, model and vintage generator.

Can we assume that it is out of warranty?

OK, actually looked at the movie.

I would say there is a metering problem. If you put a 240V light bulb on it does it flicker and dim?

I can't see for sure what receptacle socket type you are using, but if it is 240V with only two line connections and an EGC you should not expect to read 120V between one line terminal and the EGC.
If your meter is going line to line, then you have a serious problem with the wiring of the generator being intermittent somewhere.

The only way you could read 120V reliably from a 240V socket without a neutral is if there is a solid bond at the generator between neutral and EGC.

 

[ptonsparky]

Coleman hasn't been out there for years and years plus a couple years. I'm relatively sure the warranty has expired.

 

[JFletcher]

Welcome to the forum.

I'm guessing the brushes are about to fail:

http://www.alpharubicon.com/altenergy/colemanpenwu.htm

 

[RangerMike175]

The brushes are about 3/4 of their original length still so they should be fine. I'll have to check the AVR this evening and give an update.

 

[JFletcher]

The brushes are about 3/4 of their original length still so they should be fine. I'll have to check the AVR this evening and give an update.

:thumbsup:

What happens when a light is plugged in; does the brightness vary all over, matching what the meter is reading?

If it's the AVR, they run $35-75.

 

[ptonsparky]

Our village maintenance man used to do tech work for Coleman. During hurricanes when large #s of these were shipped out they would send techs down to fix units on the spot if they could.

He suggested getting to the plug that comes directly out of the Generator and making you tests there. Next if someone has attempted to incorrectly grease the bearing at the end if the genset, grease will migrate to the slip rings and cause grief.

The neutral floats at the generator.