Generators, voltage quality, and "sensitive electronics"

[rbstern]

We've had more power outages this year than in years past, and I have been remiss in not being better prepped. We have two homes on the property, each with their own breaker panel. But the homes share a well system with pump and pressure tank. If we lose power, we only have the water in the tank. Want to be able to power the well pump from backup generator.

Have a couple of 5500/4800 watt, dual fuel Duromax generators. I have used them for small projects. They are electric start, and reliably start on propane. Have avoided ever putting gasoline in them, to improve their reliability.

I have most of the wiring done to hook one to the house with the well power, via a genny plug and 240v/30A circuit. Just need to install the manual lockout disconnector and breaker in the panel.

I've read many times about the potential to damage electronics with generator power. Have never heard of a real world example.

Anyone have experience with this happening?

 

[skipmarcy]

My experience with running the 1 hp well pump I have is that I'm not sure your size generator will handle it. I've run mine on a 7500/9000 watt and it really works it to start the pump. I only use it to refill all of our water containers every several days during an extended outage - not run the house water system as normal. I think it would cause pump motor damage in the long run just from my experience trying it.

As far as the electronics damage, I've never experienced any problems with our appliances or electronics over the many years using conventional generators.

 

[Diggin It]

Before I went to generators, I relied on a variety of UPS units. I had several around the house and had a number of electronics plugged in .... TV, audio, computers, etc. Of course, that only gave me enough time to shut stuff down normally instead of a sudden outage. One of their main purposes was to filter power and bridge those short, momentary outages.

Eventually I picked up an off-brand portable generator and several cords. That worked for a while, but eventually the UPSs started freaking out when on generator, beeping, buzzing, flickering and so on. Conclusion of people I talked to is that the generator was putting out less than prime power and the UPSs could no longer handle it. No one could confirm if the generator was going bad or if it had degraded the UPS internal electronics.

I now have a whole house unit, but have not had an extended outage to see how it works. I have manually killed power and run on generator for 3-4 hours with no problem from any of then devices.

I would not trust valuable or sensitive electronics on a portable generator without some sort of extra filtering.

And no, I don't think a 5500/4800 is going to run a well pump. I'd say 10K at a minimum.

 

[Eagle1]

My well pump draws 12-15 amps running but ~30-50 amps on startup. Most consumer grade generators do not output a pure AC sine wave, more like a pulsating DC. DC electronics have a power supply and should handle that no problem. Older stuff was way more sensitive but now stuff has to deal with crappier power and grounds anyway.

 

[cqaigy2]

I use UPS's too, on the entertainment system and computer/network stuff.

I'm trying to remember the last time i fired up the well, was a 1hp 3 wire submersible, approx. 390' deep. 5KVA generator, maybe peek was 6. It was able to start and run the pump motor and pump into the cistern. We have a pressure pump too, didn't run both at the same time. Using an inexpensive multimeter, the initial current draw was around ~20 amps and would drop to around 12ish. I pumped probably a few hundred gallons into the cistern, before shutting it off. Didn't need the pressure pump because well and cistern sit uphill and provides enough drop for usable pressure at the house.

 

[blee03]

Good info here:

"In a traditional generator, the power produced by the alternator is fed (more or less) straight to the control panel. It may go through a voltage regulator or other protective devices, but the power is not necessarily “cleaned up”. Therefore, the power produced by a traditional generator has a higher total harmonic distortion (THD) than the power produced by an inverter generator. THD is a measure of how clean the power is – more on that in a moment.

An inverter generator works differently. The alternating current (AC) power produced by the alternator is sent to a rectifier, which is a device that converts the AC power to direct current (DC). This DC power is then inverted back to AC power by the computer inside the generator before it is sent to the control panel. This is where the name “inverter” comes from. Because the power to the control panel is controlled by the computer, inverter generators offer much lower THD than standard generators. THD is an important consideration when powering sensitive devices, like smartphones, tablets, computers, and televisions. These devices expect “clean” power (power that has low THD, like the wall power in your home), and can be damaged if they receive high-THD power. All WEN inverter generators use pure-sine-wave inverters, and as such, limit THD to under 1% in most cases. Traditional generators can produce THD as high as 25% in some cases."

How Do Inverter Generators Work?

NOTE: If you're looking for a more basic explanation about the benefits of inverter generators, check out our post explaining their advantages here. If you’re in the market for a new generator, you’ve probably noticed by now that there are many different types of generator – standby, portable...

wenproducts.com

 

[seville009]

I blew out the control panel to my relatively new furnace one time because the whole house generator was running too high (above 60 mhz or whatever it is supposed to be).

Could see that the lights were a little brighter when the generator was running, but I’m no electrician…..

Have the generator serviced each year now.

Also have a whole house surge protector - never had any surge issues, so I can’t really say if it works or not.

 

[Oaktree]

Most consumer grade generators do not output a pure AC sine wave, more like a pulsating DC. DC electronics have a power supply and should handle that no problem. Older stuff was way more sensitive but now stuff has to deal with crappier power and grounds anyway.

I use UPS's too, on the entertainment system and computer/network stuff.

I've found that many UPSs, especially the smaller <1000VA units (the ones you get at Staples for computers, etc.) don't like the ratty power the lower price generators put out very much. They'll keep switching back and forth between line and battery power, causing fluctuating load on the generator. Went round and round on this at a worksite where they'd put in a Home Depot Generac before we figured out what was causing this.
Some of the more enterprise-level UPSs (APC at least) have a sensitivity adjustment that allows them to accept less than ideal power quality.

 

[DieselnHooters]

Our suitcase type Honda 2000 watts inverter gen runs the 1HP pump fine, it peaks in the 12-15 amps area and the well is 50 feet deep.

 

[mrmikey]

Me personally, I wouldn't run any electronics off a non-inverter type generator. I will continue to run my well pump, water heater, lights and fridge off a conventional style and have been doing so when required for the past 10 years. At least once a winter we lose power for any where's from 1 hr to 12.
I was going to buy a new inverter style to run my heat pump but I figured in the summer it's not necessary or life altering not having AC, in the winter I have a wood stove. Besides, the price of an inverter type big enough to run what I want is way out of my price range.....Mike