What do y’all know about generators and dirty power?
 

So my house lost power for a few days. It was cold. I borrowed (with conversation on buying) a generator and wired in my furnace's. The fan blowed but the igniter didn’t fire. Polarity was correct as I checked it. The cord has a ground.

Power came back. My furnace works.

I am happy to buy this generator but I think the output is too dirty to run my furnace.

Thoughts?

Furnace is an old Trane and is on last legs.

Generator is a Generac brand inverter style.

TIA!!!

What is the peak draw to charge up and use the igniter? Did the generator have enough of a rating to provide that (as well as overhead for fan or whatever else was running on it already)

Inverter generator is pretty much as clean as it gets. What size is the generator?

Is the furnace a condensing type? Condensate tank full not allowing furnace to turn on?

It’s on 2000w. Don’t know draw. Condensate is fine.

That might be the issue. Too small for peak draw. Hmm. I will research. Thanks!

The google machine says 2000w inverter type should deliver over 16 amps. I'd be surprised if a furnace required much more than that since that's the max you'd connect to a 20A breaker which is how a furnace is typically fed.

"2000 watt" generator may refer to peak power, running power may be 1500 watts, at 120 v that's about 12.5 amps. Seems should be enough for a furnace, but look at your furnace's info plate to see its motor draw.

I bought two at HF and both run great! One for down stairs frig/freezer/lathe/ETC and heater and other is for upstairs frig and lights. Both have wheels, handles and run all night on one tank of gas which was used back in 2007 when we had a big fire in the San Diego area. They saved my late daughter's and late wife's medicines.
John the oldracer

Do you have a AC or heat pump tied into the furnace? Im thinking an interlock relay somewhere else is not turning on.

Length and size of the cord could have something to do with it.

Did your circuit board lamp throw any codes while you had the generator hooked up?

Funny that this thread appeared. Yesterday I was deep in study about using a genset to run a welder. I was on WeldingWeb after a 9 year absence. I found out what I need to know and a lot more when this link was offered:
http://www.screenlightandgrip.com/ht...enerators.html
Craigster?
Anyway, circuit boards don't like generators all that much. Of course YMMV. But they are fine with resistance heating and incandescent lighting all day long. I assume older fridges and freezers won't have a problem.
Anyway, and I don't have a recommendation, an electronic filter can clean up the power and provide a distribution system whereas you really don't have to hook up through your panel. You really must disconnect what you power through the generator and not feed the house in any way w/o a lock out transfer switch.

The quick take away from the link is that there are 4 types of generators. Not just talking about inverters vs. conventional.

I can tell you that I ran our furnace a few years ago off a Honda 2200 without issue. It was also also powering cell phone chargers and internet router.

Are you sure there are not 2 separate circuits to the furnace? Is the thermostat some new fangled thing with a separate power source?

Dunno about generators, but once had a gererator that was super clean.

..if you don’t get this, you ain’t an old timey Pelican.

I have a Harbor Freight 10kW. I would never use it for anything sensitive, no TV's, and not my new fridge.

It's fine for motors, heat, water heater, deep freeze, and lights.

I suspect the OP's problem was voltage drop. Try again, and use a Fluke max/min meter at the furnace to measure the voltage.

The more sensitive devices should be powered by an inverter generator.

Is there 24 Vac control power to the furnace and T-stat also?

In 25+ years of running "affordable" 5-10KW generators, I've never had an issue with computers and TV's and such. Just check the spec's. To power sensitive equipment, you need a generator that produces a THD of less than 5 percent, also known as clean power.

For what its worth, I test ran my furnace from my Harbour Freight inverter generator just now - was fine. But its a 9500 watt generator.