Furnaces and THD with generators

[hbiss]

Um, they have. Prices on inverter generators have come way down in recent years especially with Harbor Freight now a big player in the generator game.

No, I'm talking about large permanently installed units with an ATS. Not aware of any that use inverter technology. No idea what the output waveform looks like, are they cleaner than smaller standby units? Maybe they don't need inverter outputs? Are some better than others?

-Hal

 

[zbang]

No, I'm talking about large permanently installed units with an ATS. Not aware of any that use inverter technology. No idea what the output waveform looks like, are they cleaner than smaller standby units?

I'm wondering how they can mess up the waveform of a rotating machine unless the other loads are distorting the wave and the generator isn't strong enough to keep things right.

How do the furnace controls behave when on generator with no other loads? or just with the blower? (does that have it's own VFD?)

 

[synchro]

I'm wondering how they can mess up the waveform of a rotating machine unless the other loads are distorting the wave and the generator isn't strong enough to keep things right.

The simple low cost excitation circuits in portable generators introduce harmonics and often spikes on the AC output. The usual self excitation is is connected to the AC output, and the effects of nonlinear and transient loads propagate back through the excitation making things worse.