“Clean” is a relative term. No generator powered by an internal combustion engine produces “clean” power. If you look at the sine wave from any generator like this it will have all sorts of noise on it and the waveform will not be symmetrical or smooth.
What will matter most, if it cares, is voltage and frequency. Mostly frequency. Dig out some specs from Lennox and see what the range of operating voltage and frequency is for your furnace. Your generator, being a Generac, probably has a mechanical (droop) governor. If so, expect frequency variation of about +/- 5% from no load to full load. That’s about 3 Hz, meaning it could go from 57 Hz to 63 Hz. Again, go back toLennox and get specs. You’re not the first consumer to run their furnace on a generator, so they should be able to offer some guidance. Also, if there are other loads on the generator at the same time as the furnace, they will tend to dampen some of the variations in frequency and voltage. -D > On Jan 11, 2019, at 12:22 PM, Randy Bennell via Mercedes > <mercedes@okiebenz.com> wrote: > > How does one tell how "clean" the power is from a generator? I had no > concerns about my generators being able to power my old Lennox furnace given > it was a 1981 vintage and had nothing really electronic in the controls. > However, we replaced the furnace about 3 years ago with a high efficiency > Lennox that now has circuit boards etc. Do I dare try to run the furnace from > a generator if the need arises or am I asking for trouble? I would not want > to damage the furnace. > > My generators are a Generac that is 10 or more years old. Something like > 7500W (cannot recall exactly) with B&S engine and another older unit from the > 70's powered by a 2 cylinder Wisconsin engine running on propane (10KW) or NG > (8KW). I have yet to ever power it up but bought it because of its ability to > run on NG so that I would not have to be concerned with gasoline issues. The > Generac currently needs the carb cleaned I think as the last time I tried to > start it up, it would not go. I did not prime the cylinder with gas etc but > previously, it had always started when I tested it so it needs some work at > the moment. Waiting for warmer weather to have a closer look at it. > > It has been suggested to me that I might want to acquire a backup power > supply intended for a computer and use it to power the furnace and use the > generator to keep the power supply charged up. That would provide a clean > power source for the electronics. Not sure how big it would need to be to > power the furnace blower motor or if there is a reasonably simple way to > separate the two so that the generator could run the blower motor without > going through the backup power supply. > > We have pretty solid power here and I have never needed the generators so far > but the idea of a backup appeals and I have the equipment (if it was ready to > use). > > RB > > > _______________________________________ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
