Two years ago, after Hurricane Irma, I bought a generator at Costco. A Firman, 9,400 watt duel fuel model. I also had the house wired with a transfer switch so that I can plug the generator into the main panel and run the whole house. Well, I cannot run the whole house, but I can pick and choose and I can run the central A/C, which is probably the most important thing after the fridge in Florida in August and September.

The generator was still in the box until Friday. I took it out of the box, got it set up and gave it a little run time to break it in. Then on Saturday morning I went ahead and shut down power from the pole and tested out the generator. It ran the central A/C, the fridges and other basic items that were plugged in.

Later that night, the ceiling fan in my bedroom quit working. Just the fan part, the lights still work. I did not think much of it, it is probably 7-8 years old and I have had the motor go out before. Our bedroom ceiling fan runs at least 12 hours per day.

But then last night, I went to use the convection oven. It's one of those dual convection ovens with a top and bottom and panel that can be removed to create a larger oven. The top part does not seem to work. All the electronic display stuff works, but the thermostat seems stuck at 150 degrees and the top does not heat. But the bottom half seems to heat and work fine. FWIW, the oven is a Samsung and is probably 8-10 years old.

Everything else in the house; computers, printers, TV's, modems, etc, seems to be working fine.

I know there is probably no good answer, but did this set up somehow zap these two items?

You'll get a lot of opinions , but there is no way to really know . The fact that a lot of other electronics are working fine makes it hard to determine .

The only way to know is to test the generator without a load and see what Hertz and voltage it is putting out, then test both Hertz and Voltage with a load. If the Hertz or voltage are way out of spec, high or low, then yes it absolutely can fry electronic stuff and motors. Although a basic motor like a fan motor would be more resistant than an oven with electronic circuit boards. It is entirely possible the governer is set wrong on the generator.

Edited to add, you should see voltage between 220-250 volts and hertz right around 60 hz. 58-63 hertz would be an acceptable range. Loaded the generator should be 60hz

quote:

Originally posted by jimmy123x:
The only way to know is to test the generator without a load and see what Hertz and voltage it is putting out, then test both Hertz and Voltage with a load. If the Hertz or voltage are way out of spec, high or low, then yes it absolutely can fry electronic stuff and motors. Although a basic motor like a fan motor would be more resistant than an oven with electronic circuit boards. It is entirely possible the governer is set wrong on the generator.

Edited to add, you should see voltage between 220-250 volts and hertz right around 60 hz. 58-63 hertz would be an acceptable range.

I'll add, it could also be a square wave vs sine wave issue as well. A lot of generators generate a square wave that is full of harmonics and some equipment does not like that at all. It is generally computer equipment that's affected.

I have to agree with jimmy on this.
You have to find out what output you are getting from the generator.
Over voltage is as bad as under voltage.

If you can find an electronics shop that has an Oscilloscope , then you can see the waveform and the frequency , etc.

A Fluke Scope meter would do it too .

quote:

Originally posted by jimmy123x:

Edited to add, you should see voltage between 220-250 volts and hertz right around 60 hz. 58-63 hertz would be an acceptable range. Loaded the generator should be 60hz

I have a digital multi-meter. The only thing I ever use it for is to make sure the wires are cold after I flip a circuit a breaker, like when I replace ceiling fans. I am guessing I can test the voltage of the generator with this? But not the hertz?

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I am guessing I can test the voltage of the generator with this? But not the hertz?

Depends on the meter.

You suspect the generator, but maybe there's other possibilities. I don't want to assume anything, so a few questions.

Did you actually use the ceiling fan and/or the convection oven while your house was being powered by the generator? If no, I'd have a hard time believing the generator was at fault.

When was the last time you used the convection oven? Maybe it's been broken for awhile and you are just noticing it now?

Is the fan on a speed control switch? Is the switch bad? Motors usually do fine on square wave power inexpensive generators put out, but electronics may not.

Have any lightning strikes recently? I lost a microwave, TV and some other stuff to lightning once.

No way to diagnose anything for sure with out being there. I'd say everyone has given you good advice thus far.

Every time the lights go out, even for a second our Maytag oven won’t work afterwards. First time was when I was cleaning cast iron on self clean mode. Last time oven didn’t work after power flickering. We thought it was done for. Wife did google and YouTube searches and found which buttons to push in what order. Takes awhile but eventually she hit right combo. It works again.

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Originally posted by trapper189:
You suspect the generator, but maybe there's other possibilities. I don't want to assume anything, so a few questions.

Did you actually use the ceiling fan and/or the convection oven while your house was being powered by the generator? If no, I'd have a hard time believing the generator was at fault.

When was the last time you used the convection oven? Maybe it's been broken for awhile and you are just noticing it now?

Is the fan on a speed control switch? Is the switch bad? Motors usually do fine on square wave power inexpensive generators put out, but electronics may not.

Have any lightning strikes recently? I lost a microwave, TV and some other stuff to lightning once.

No, I did not use the ceiling fan or oven while the generator was providing power. But I did not unplug them or trip those circuits either.

We use that oven probably on average once a week. Never more two weeks without usage. So it gets regular usage.

The fan has separate wall switches for the lights and fan. I suppose the switch could have gone bad. Or be loose. When the fan quit working, the next day I flipped the switch on and the fan did run for a little while before it stopped again.

No lightning strikes that I am aware of. However, central FL is the lightning capital of the world, so it cannot be 100% ruled out.

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Originally posted by stoic-one:

quote:

I am guessing I can test the voltage of the generator with this? But not the hertz?

Depends on the meter.

Craftsman model 82141. I looked it up, does not do hertz. Is there one recommended? Or should I just order a basic one off Amazon?

Small, fractional AC horsepower motors synchronize their rotation rate to the line frequency. You can measure that with an app for a smartphone (it blinks the camera’s light like a strobe so you can “stop” the motor’s apparent rotation visually to get a reading). If you have both items you could measure the motor rotation rate using the generator and compare that to its rate running off the AC line voltage. That’ll tell you if there’s any difference in hertz between the two power sources.

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Originally posted by holdem:

quote:

Originally posted by stoic-one:

quote:

I am guessing I can test the voltage of the generator with this? But not the hertz?

Depends on the meter.

Craftsman model 82141. I looked it up, does not do hertz. Is there one recommended? Or should I just order a basic one off Amazon?

This would work, you could plug it into an extension cord to the generator, even with nothing attached to it, and it would give you volts and hertz, also reads amps or kilowatt hours for the appliance plugged into it. It's pretty foolproof to use and cheap.

https://www.amazon.com/P3-Inte...83795260952595&psc=1

Or you can buy a multimeter, but need one that measures Frequency/Hertz.

quote:

Originally posted by tsmccull:
Small, fractional AC horsepower motors synchronize their rotation rate to the line frequency. You can measure that with an app for a smartphone (it blinks the camera’s light like a strobe so you can “stop” the motor’s apparent rotation visually to get a reading). If you have both items you could measure the motor rotation rate using the generator and compare that to its rate running off the AC line voltage. That’ll tell you if there’s any difference in hertz between the two power sources.

While that's a helluva an idea & a good tool to have in the toolbox, I doubt it's likely to be a frequency problem with only motors or heating elements croaking, especially ones not in use during the generator power time.
Sine/square wave issues with electronics are caused by weak/inadequate filtering (read, cheap) on the input circuitry and REALLY crappy generators. It's not as big of an issue as people make it out to be. It won't croak your iPhone for 100yd away....
I'd bet most issues are from surges due to power interruption (hence the generator usage) rather than the generator itself.

I'd turn off the devices & flip the breaker(s) off for a while & see if it 'resets' whatever isn't working.

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Originally posted by snidera:

quote:

Originally posted by tsmccull:
Small, fractional AC horsepower motors synchronize their rotation rate to the line frequency. You can measure that with an app for a smartphone (it blinks the camera’s light like a strobe so you can “stop” the motor’s apparent rotation visually to get a reading). If you have both items you could measure the motor rotation rate using the generator and compare that to its rate running off the AC line voltage. That’ll tell you if there’s any difference in hertz between the two power sources.

While that's a helluva an idea & a good tool to have in the toolbox, I doubt it's likely to be a frequency problem with only motors or heating elements croaking, especially ones not in use during the generator power time.
Sine/square wave issues with electronics are caused by weak/inadequate filtering (read, cheap) on the input circuitry and REALLY crappy generators. It's not as big of an issue as people make it out to be. It won't croak your iPhone for 100yd away....
I'd bet most issues are from surges due to power interruption (hence the generator usage) rather than the generator itself.

I'd turn off the devices & flip the breaker(s) off for a while & see if it 'resets' whatever isn't working.

Generators run at a constant RPM to produce a certain frequency (and volts usually). They have a governor which adjusts throttle to match the load to keep them at that frequency. 60 cycle/hertz generators usually run at either a constant 1800 or 3600 rpms depending on the motor. For 50 cycles European power they simply govern them to run 1500 or 3000 rpms. If the governor isn't adjusted properly it's very easy to fry everything by producing either too many cycles or too little cycles (and usually volts, some have additional voltage regulation, non inverter generators). a lot of gas portable generators can have a tough time limiting the throttle enough to give the proper cycles for very light loads, or if heavily loaded can have trouble keeping up and keeping the cycles and rpm where they need to be. Also as they age, they generally need minor governor adjustments.

Engine RPM's are 1800 or 3600 depending on the number of poles in the generator .

Sounds like a classic over-voltage/under-voltage situation to me. If you had lost a neutral, you would’ve lost computers and probably many other things.

Only way to know for sure—as was stated earlier—is to test for voltage leaving the generator between conductors and test to ground.