Is it possible to "clean up" my older generator's power for sensitive electronics?

[newbury]

I've several older, but well running generators in the 7K to 15K range. But with the increasing addition of sensitive electronics to almost EVERYTHING I'm apprehensive about using them to run my devices.
I had initially thought just slap a UPS in the loop, but now they can be fried by dirty power (or so I've read).
Is there any inexpensive solution short of buying all new generators?

 

[mikester]

Is there any inexpensive solution short of buying all new generators?

No

 

[Jrasband]

I am very curious as well. I am using a non-inverter generator to charge solar batteries and am worried about risk.. So far no problems so I am worried about long term.

 

[MattB4]

The biggest problem with small generators is that they may not do a good job of frequency or voltage control with changing loads. Often they do not have much in the way of speed governors nor the inertia of a larger generators.

However if your older generators are good quality I would not worry about using them. Modern electronics are pretty good at being protected from supply irregularities.The bigger worry from a non stable supply is your old standard motors. Such as the compressor in your refrigerator or well pump.

 

[LouNY]

An online UPS will do the job, but they are not inexpensive by any means;

 

[sea2summit]

UPS will do it, don’t have to go super large like the ones Lou posted unless you need that much clean power. A quick search on Amazon has them as low as $70…probably wouldn’t recommend that one though. I’d just inventory all the electronics you’d like to power and see what your load is plus any surge load and find one in the size you need.

 

[Oaktree]

I had initially thought just slap a UPS in the loop, but now they can be fried by dirty power (or so I've read).
Is there any inexpensive solution short of buying all new generators?

One thing to beware of is that some UPSs are not very tolerant of ratty input power. I haven't heard of one getting fried, but they'll often switch to battery and stay there (or toggle back and forth...see below) if the power coming in isn't clean enough. Some have sensitivity adjustments, but they're not always intuitive.

About 20 years ago I was involved with a new generator install at a work site. Home Depot-grade 8 kW Generac. Generator tech could not get it to run smoothly, engine speed would surge, fall back surge, fall back. He eventually threw up his hands and stopped returning calls. Some troubleshooting on my part revealed the UPS activity I described above. Bypassed the UPS and the generator ran smooth as can be.
A little research showed an unlabeled button on the back of the UPS...turns out it would step thru 3 sensitivity levels. Found one that made everything happy.

Don't know how old your generators are, but I have a box store Champion 4000W unit and have had no issues. Mostly used to run refrigerator & freezer in a power outage. I can live without tv, internet, etc. for a day or two if necessary so I've never tried to run a computer, etc. on it.

 

[sea2summit]

One thing to beware of is that some UPSs are not very tolerant of ratty input power. I haven't heard of one getting fried, but they'll often switch to battery and stay there (or toggle back and forth...see below) if the power coming in isn't clean enough. Some have sensitivity adjustments, but they're not always intuitive.

About 20 years ago I was involved with a new generator install at a work site. Home Depot-grade 8 kW Generac. Generator tech could not get it to run smoothly, engine speed would surge, fall back surge, fall back. He eventually threw up his hands and stopped returning calls. Some troubleshooting on my part revealed the UPS activity I described above. Bypassed the UPS and the generator ran smooth as can be.
A little research showed an unlabeled button on the back of the UPS...turns out it would step thru 3 sensitivity levels. Found one that made everything happy.

Don't know how old your generators are, but I have a box store Champion 4000W unit and have had no issues. Mostly used to run refrigerator & freezer in a power outage.

I’m not doubting your story at all, or the concerns you raise. I’d just say UPS, like many electronics, have come a long way in 20 years.

 

[LouNY]

UPS will do it, don’t have to go super large like the ones Lou posted unless you need that much clean power. A quick search on Amazon has them as low as $70…probably wouldn’t recommend that one though. I’d just inventory all the electronics you’d like to power and see what your load is plus any surge load and find one in the size you need.

If it is not an "online" or continuously converting and regenerating the power it will not clean up the provided power from noise.
A switching UPS will not clean up the incoming power.

 

[MattB4]

As others mentioned a UPS is not for cleaning power it is to maintain power to components with the loss of the the primary power source. If the primary power source is a small generator it may decide the generator output is not within specs for frequency or voltage. This does not mean the generator is outputting "dirty" power.

You see a lot of nonsense on the web about needing an inverter generator because standard generators are not PSW (pure sine wave) and the new inverter generators are. Regular generators are PSW by nature. What makes the new inverter style generators good is they can operate at varying engine rpm and loading changes while maintaining a stable output. Thus more efficient use of fuel. Put in Eco mode they run at low rpm with low loads and than idle up for higher loads. A old generator is forced to operate at a fixed rpm.

 

[D'oh]

Sensitive Electronics such as???

Older Generators such as???

I run Champion Generators at my Cabin. Before going Solar/Gen I ran a larger 4000W which did actually fry a couple of VCR Players, but only on Shut Down. If I unhooked the Power before shut down, all was fine.

Then after Solar/Gen set up, I run a 1200w Champion in the evenings to Top Up my Bank and watch TV.

Well Over 2000hrs of 40" LCD and Blu Ray time, and have never fried any. Even with a 30A Battery Charger kicking in and out while watching.

So, I am not going to warranty a Desk Top or such, but if you are careful, use a Surge Bar, Switch it off before the Generator, and Don't think a B&S Powered Commercial/Construction Generator is the same as a Recreational Generator only Louder. You should be fine.

 

[buckeyefarmer]

My old generator ruined a board on my pellet stove. I now only run electronics with inverter UPS. Check out THD on the generator, or put a scope on it and see how bad it is.

 

[MattB4]

...

I run Champion Generators at my Cabin. Before going Solar/Gen I ran a larger 4000W which did actually fry a couple of VCR Players, but only on Shut Down. If I unhooked the Power before shut down, all was fine.

...

As you found out it is a good practice to turn off things before shutting down the generator. It is also good to not start up a small generator heavily loaded. Ideally no loads until the generator is up to speed. Loads should be introduced one at a time since startup current demands can overwhelm a generators capacity.

BTW, try to never have your generator run out of fuel during operation.

 

[ericm979]

The biggest problem with small generators is that they may not do a good job of frequency or voltage control with changing loads. Often they do not have much in the way of speed governors nor the inertia of a larger generators.

However if your older generators are good quality I would not worry about using them. Modern electronics are pretty good at being protected from supply irregularities.The bigger worry from a non stable supply is your old standard motors. Such as the compressor in your refrigerator or well pump.

We have a lot of computers and all the usual home equipment. I've been running them all off a 25 year old 5kw Honda generator during our frequent and often extended power outages. I have not had any electronics fail due to the generator's power. However I don't run the well off the generator as I have a 10k gallon tank that gravity feeds the house.

You can put a UPS in front of equipment that you're concerned about, but you probably don't need it just for protection.

A 7-14kw generator's got enough inertia so it won't slow too much under most loads. Maybe if you're welding or have a big AC unit without a soft start it would.

 

[ponytug]

I've several older, but well running generators in the 7K to 15K range. But with the increasing addition of sensitive electronics to almost EVERYTHING I'm apprehensive about using them to run my devices.
I had initially thought just slap a UPS in the loop, but now they can be fried by dirty power (or so I've read).
Is there any inexpensive solution short of buying all new generators?

As others have noted, it does depend on exactly what you have now, and what you want to run. Do you know that you have dirty power? If so, how do you know?

Brushed generators tend to make electrically noisy power, as do cheap (and some older) voltage regulators. Generators can also be "dirty" in a variety of ways; unstable frequency, unstable voltage, lots high frequency static and / or harmonic frequencies. Devices are sensitive to dirty power in different ways.

Most electronics will be ok behind one or two high quality surge suppressors; higher joule ratings are better. An online pure sine wave UPS that runs your electronics off of its battery 100% of time is a great way to make clean power, but they aren't cheap.

Larger, older generators tend to make pretty good power because they aren't underpowered, and have a large inertia in the engine and windings to run through large load changes. However, they do have to be in good shape mechanically and electrically. Are they?

Ideally, your home loads should be 80% of the generator capacity at least some of the time. There is also the issue that a large generator serving a small load will burn a lot of fuel per kWh of power, so it is best to match generator size to the load being served.

I think @MattB4 makes some excellent points on generator operation. Start your generator, let it warm up, then add loads one at a time, and try not to make large loads the first or last thing that you add/or remove, and then the same thing in reverse. Letting a generator run out of fuel under load is a great way to generate lots of problems for you.

All the best,

Peter

 

[WinterDeere]

One thing to beware of is that some UPSs are not very tolerant of ratty input power. I haven't heard of one getting fried, but they'll often switch to battery and stay there (or toggle back and forth...see below) if the power coming in isn't clean enough. Some have sensitivity adjustments, but they're not always intuitive.

What you're describing is the typical behavior of cheap consumer-grade UPS's, and yes, I have a half dozen of them. They work fine on home power, as they're not toggling back and forth every few seconds. Like you, I suspect the contactor/relay would give out after awhile on one of those, if run on anything with really unstable voltage.

But there are also UPS's that don't toggle, just generating clean sine-wave inverter power from the battery all day long. I never dug into the schematics on them, but assume they must have separated charging and inverter circuits, with the battery used as a large capacitor/isolator in-between. Essentially, they are ALWAYS on battery power.

I have bought these several times many years ago in 3-phase, from Sola, Mitsubishi, and JDS Uniphase. I remember all of them also made single-phase variants. Some of the units I was buying were large enough to power a full lab, but some were also small 6U rack-mount units for powering just a single machine.

 

[ponytug]

...

But there are also UPS's that don't toggle, just generating clean sine-wave inverter power from the battery all day long. I never dug into the schematics on them, but assume they must have separated charging and inverter circuits, with the battery used as a large capacitor/isolator in-between. Essentially, they are ALWAYS on battery power.

I have bought these several times many years ago in 3-phase, from Sola, Mitsubishi, and JDS Uniphase. I remember all of them also made single-phase variants. Some of the units I was buying were large enough to power a full lab, but some were also small 6U rack-mount units for powering just a single machine.

Those are called online or inline UPS. They aren't cheap, but you can occasionally find them surplus from a business or data center remodel.

Line-interactive vs Online vs Offline UPS | FS Community

There are three topologies of UPS systems: offline vs line-interactive vs online. What are their differences and how to choose the right UPS system for your design? This article will make a comparison among these three designs in four aspects: operating principles; functions; benefits and...

community.fs.com

Like you, I have bought more than a few over the years. I would comment that as the online UPS provides power to the equipment 100% of time, the quality of the UPS pure sine wave power becomes critical. I would not consider buying a unit from anybody but one of the big manufacturers that has been in the business for decades.

All the best,

Peter

 

[WinterDeere]

Those are called online or inline UPS. They aren't cheap, but you can occasionally find them surplus from a business or data center remodel.

That was it. Thank you for the memory refresher. I was buying these 20 - 25 years ago, for various equipment and laboratories, and do remember now they were called "online UPS's". Never had to buy one for home-scale use, so I have no clue as to the cost of smaller single-phase units, and the pricing that does stick in my memory is all 20 years old now.

I suspect the biggest issue may be finding one with our typical 115+115V = 230V balanced split-phase output.

 

[MattB4]

Although not thought about much the grid power you get can be rather poor quality. Not as often a problem in the US with the exception of weather related events and equipment failure but other countries deal with some really dirty incoming utility power. I recall from several years back when my Mother took her RV to Mexico and ran off their power. She lost a microwave and also a small TV due to the poor power available at the RV park. She had not problems with running off the RV's emergency generator before this.

Another thing about UPS. Not all of them are PSW. many are MSW. Works fine for many things but not all.


ETA: For fun and to understand what is happening when you use a generator imagine that you are in your car on a flat straight road. You are required to maintain 60mph or your car will detonate into a fiery twisted ball of steel, glass and rubber. You have a small margin of speed above and below 60mph but not much.

Everything is ticking along great until you come to a hill. Going up the hill your speed starts to drop if you do not push down on the gas pedal. (This is analogous to placing more load on the generator and the governor of it reacting). After reaching the top of the hill you level back off and you have to release some of the gas pedal pressure so that you speed does not exceed 60mph. The same thing happens in reverse if you encounter a down grade. If the hill (load) is too much for your engine to power up or the brakes to slow down you end up in trouble.

 

[kf4uda]

When we bought our travel trailer I looked into RV surge protectors. Progressive industries was the brand of choice. We purchased one of these:

https://www.amazon.com/PROGRESSIVE-INDUSTRIES-EMS-PT50X-Portable-Protector/dp/B01N9MOY7B/ref=sr_1_4_sspa?crid=2ISY60KF17RXQ&keywords=rv%2Bsurge%2Bprotector%2B50%2Bamp&qid=1700753365&sprefix=rv%2Bsur%2Caps%2C126&sr=8-4-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

I have never thought about using one for a generator since I have an inverter generator but it would be worth a look. They have different sizes and even hardwired options.