Generator question and maybe a good buy for someone.

I purchased the Champion 7000/9000 generator from Costco a few weeks ago, on sale for $699 (normally $749), now they have the new model and it's on sale for $549 (normally $699) until 6/24. The old model has great reviews, no data on the new model yet.

https://www.costco.com/Champion-Powe...100347350.html

I still haven't opened the box so I'm considering returning which prompted my question. The new generator is 15% THD while the old one is <5%. Other than that, the new one has 3 hours additional runtime on gas (no improvement with propane) and doesn't seem to come with the 25' 30amp extension cord and battery charger.

The main plan is to use this with a transfer switch to power the well pump and a couple circuits in the house if there's an outage but we'll probably come up with other uses.

Is the difference in THD worth keeping the old one or would you swap it out for the $150 and a trip back to Costco?

For the pump, no. For electronics, i'm curious since they power off a "transformer" when charging if there'd be any issue. You should check amperage draw of the pump.
It might be in your best interest to run one for the well and 1 for the house. Even with a Gas heating system, initial start will load that generator up. Throw in possible electric dryer, and other necessity use electronics, i'd say run 1 on each.

The one with less than 5% Total Harmonic Distortion is pretty good. That is the difference in price between the models, clean AC sine wave power is a big deal with electronics such as refrigerators with a brain box, microwaves, pc's, TV's, etc. IF you are running purely electric motors, more THD is ok to a point. Start-up draw current or in-rush current is what taxes generators to their limits when starting electric motors as it is much larger than running current.

https://www.consumerreports.org/cro/...uide/index.htm

Was planning to pick one of these up myself. Where did you find the THD of the new model generator reported?

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Originally Posted by DenverGP

Was planning to pick one of these up myself. Where did you find the THD of the new model generator reported?

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I emailed their support to ask the difference between the models and that's what they sent me. They have a bunch in stock at the Lone Tree location, probably others as well since they just started getting them in.

Costco website also show Firman dual fuel 7500 running watts generator for $649, claims THD of 5%.

https://www.costco.com/Firman-Power-...100417697.html

I've seen several articles claiming that only the "Inverter" generators will have a guaranteed THD of 5% or less, and that non-inverter generates that claim 5% will be anywhere from 5% to 15%.

Quote:

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Originally Posted by DenverGP

Costco website also show Firman dual fuel 7500 running watts generator for $649, claims THD of 5%.

https://www.costco.com/Firman-Power-...100417697.html

I've seen several articles claiming that only the "Inverter" generators will have a guaranteed THD of 5% or less, and that non-inverter generates that claim 5% will be anywhere from 5% to 15%.

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That is about what I have found. Not saying a conventional genset cant get to 5%. If the one you have give you a good power factor, and you're getting a true 60 htz I'd call it good.
I've run lots of elctronic of old generators. Even some sophisticated broadband equipment. You'll be fine.

Thanks for all the feedback, I think I'm going to just keep this one. Mainly because it's a PITA to pack it up and take it back, even though it's unused.

I get that most people that say <5% are stretching the truth but it's interesting when the manufacture outright says this one has much cleaner power than another of their other models in the same output range.

This is another response from them "The machine (100155) also produces less than 5% total harmonic distortion. While both machines produce clean and usable power, the model 100155 goes a step farther to create a very clean waveform that particularly sensitive electronics may require. An example would be some high end furnace control boards."

I still have to the 24th if I change my mind. If anyone has bought the new one and tested it out I'd be interested in your feedback.