Powertech Generator Voltage Spike

[Dthomas9572]

Today I noticed one of my Trace Inverters was kicking on and off with my generator running. I have a Powertech 17.5 KW. The leg on the inverter that was kicking off was showing 130 - 133 volts. The other was in the 120 - 121 range.

It worked perfectly when there was no load, but when I turned on a AC it spiked. When I turned on two cruise airs it spiked to 140. When hooked up to shore power Trace inverters work as they should.

The generator engine sounds and runs great. Do I possibly have a regulator issue? Or possibly something else with generator?

[Gil_J]

Unless you have a flaky neutral you probably have a bad voltage regulator on the generator. PowerTech stocks them in volume.

[Dthomas9572]

Thanks Gil, I have a call into Powertech. What do you mean by flaky neutral?

[Gil_J]

A loose or otherwise poor neutral connection can result in one leg going up in voltage. While one side is going up in voltage the other leg would go down. You didn't report one leg going down, so it's likely the VR. It's easily replaced. Some were mounted on the power head just behind the motor.

If you see it, with the generator off, take a jeweler's screwdriver and rotate the only adjustment back and forth a few times trying to return it close to the same position it was in. Sometimes this can help, at least for a while.

[Dthomas9572]

Ok, lots of trouble shooting. After a morning at my mechanic and on the phone with power tech support here is what we found

1) As per power tech is is completely normal for there to be a spike in voltage when a load is put on generator is not balanced.
2) It is normal that the trace inverters are seeing the spike in voltage and shutting off
3) this was operator error on my part. When I turn generator on I need to turn Cruise Air on Inverter 1 and Cruise Air on Inverter 2 first. They will be in balance. Wait a bit and then turn on Cruise Air 3 after compressors on 1 and 2 have settled down.

I have been good about power management in other areas, but not in this manner. Live and learn.

[Fratto]

On our 1999 CC with power tech, we routinely see unbalanced loads. We have two AC units on the A phase and only one unit on the B phase. The single unit on the B phase is in the rear and tends to cycle more often than the front or mid units. Therefore it is not uncommon for the A phase to have 30+ amps while the B phase is near zero. Even so, we have never seen voltages in the 130V range. We do see low voltages of 108 or so on phase A when phase B is unloaded. I have been meaning to call power tech and talk to the about their regulator technology but have not done so yet. I would turn off the mid unit but with one t-stat that is extremely annoying, once it is working I tend to leave it alone.