Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

generator voltage for newer furnaces with solid state

I have 2 portable generators, a 5K Generac that I picked up on special after the bogus Y2K scare at a good price and a Hondo EU2000i that I bought for doing home shows.

I never did any research before I got the Generac, but found out later that Generac generators can have less than 'tight' control of the frequency (60 Hz) and voltage than other units do. As a rule, I use the Generac for lighting and non-electronic functions.

The Hondo is another story. The inverter used in it is supposed to keep the frequency and voltage close to the norms that would allow you to use it on items (like modulating, VS furnaces and computers) that have close tolerances as power quality goes.

All this being said, I actually load tested both generators the other night when snow and ice were in the forecast. For those that didn't know this, I live slightly north of Atlanta, Georgia and any kind of frozen precipitation can really wreak havoc on the locals, me included. Both generators worked fine and I ran them under a good (the Hondo) to fair (the Generac) loads, using 3-500 watt halogen lights and a portable compressor.

If the conditions were snowy with power loss, I'd simply run extension cords to the appliances that need power (one freezer and one refrigerator) from the Generac and probably a few lamps. I'd probably drill a small temporary hole in my Hardi-Plank to power my RGFD modulating furnace with a variable speed blower from the Hondo. When I get my boiler/indirect system up, it will be placed on a transfer switch along with the furnace to be connected to the inverter generator. No matter how I do this, I will have some kind of power conditioner/UPS placed in the circuit as additional protection.

Speaking of transfer switches, I have one (again bought on special after Y2K and kept 'lost' for a while {That's where it went to!} ) that I will be wiring in so I can run the rest of the selected circuits in the house in the event of an extended power failure.

BTW, a buddy of mine commented that he was surprised I bought a Japanese generator, the Hondo. I realize that's not how it's actually spelled, but it's the way I spell it. All my vehicles except my tractor are American.


  • Loren Scott
    Loren Scott Member Posts: 1
    generator voltage for newer solid state controlled furnaces

    I have constructed an alternate wiring circuit in case of power outage that includes
    a surge arrestor for a Rheem RGDG series furnace with a solid state control board. All the Rheem techs will say is that generators are not recommended. Has anyone had problems with this type of set up?
  • carol_3
    carol_3 Member Posts: 397

  • Jon_10
    Jon_10 Member Posts: 47
    Generator sets

    I work in a facility that has generators in each building plus a main generator that will run everything on the grounds. The main generator is a 16 cylinder Cat. that burns 110 gallons of #2 oil per hour at full load. All of the generators have a time delay on the switch to generated power so the generator can get up to speed and constant voltage before the switching occurs. This takes very little time but is required so it does not fry our voltage sensitive circuits because of low/high voltages. Most good generator automatic switches have this feature.
  • My recommendation exactly

    is a time delay relay to insure full voltage. I have my sons Generac set up to operate that way in his electronically saturated home. It works great! Get in touch with the people who make the generator and they usually have a compatible relay for your unit.
This discussion has been closed.