Generator Damage Electronics?

[Travelover]

We lost power for 4 days around the New Year holiday and I ran my 4000 watt Coleman generator about 16 hours a day to keep the house warm and run the well pump. After a few days I noticed that my internet modem would drop out when the generator was starting the furnace. Eventually the modem quit working at all.

This modem failure got me to thinking that maybe other electronic devices are at risk when running a generator. I'm thinking of upgrading my furnace to a high efficiency model with electronic circuit boards and ECM blower motor. I know the replacement cost on these components is high.

My question is how great of a risk is there to running a high efficiency furnace on a generator? Would it benefit from some kind of surge protection?

 

[tommu56]

I would bet it died from voltage sag if it has a wall wort see if it has power coning out if it they have a fuse in it and you cant replace fuse.
Most low price generators don't have a sophisticated voltage regulation usually just a cap or 2

tom

 

[Mighty Dodge]

Electronics are sensitive to ac power it has to be clean, nice sine wave. I have an old Lincoln G8000 welder/generator that I crank up if the powers off for more than 12 hrs. My pc runs fine off of this but my new electronic washing machine wont even turn on when running off the generator.

M.D.

 

[Dargo]

Did you run extension cords or backfeed your panel? Either way, that's a pretty small generator. Low voltage can damage electronics as much as high voltage/surges. I had to run on generator power for a full week. Unfortunately I failed to purchase a 30k to 40k generator like I wanted and had to run on only 11k of generator power. I kept things to a minimum and the only problems I have are about a dozen blown electronic items from the huge power surge I received about 30 seconds after my power went off. It acted like it was coming back on but my lights were really bright and my TV sets started smoking. I then lost all power for 7 days.

I'm still making my list of destroyed items, but I lost 3 computers, my entire computer networking system, 4 TV sets, 3 A/C units (yes, in the winter no less!), several ceiling fans, security cameras etc., etc. The adjuster from State Farm seemed to want to focus on whether I was trying to run everything on too little generator power since the insurance company knows low voltage kills things. I had to send a computer and TV off to a company they selected to verify they were killed by a power surge, which was verified.

 

[heehaw]

i retired 4 years ago, after over 30 years working on electronic equipment: i used some pretty expensive constant voltage transformers on a lot of equipment, with no problems, until i put a scope on the output of those transformers: they put out the worse looking wave i had ever seen. never had any trouble with the equipment that was powered by those things, but i did away with them anyway: i just could not see how it kept from damaging the equipment: that said, i don't run any of my electronic equipment with a generator: i have a high eff gas furnace, an i wouldn't dare plug it into a generator. i use a "kill-a-watt" to verify the voltage and freq coming out of the generator, but would rather do without than have to start fixing things.
heehaw

 

[Travelover]

I would bet it died from voltage sag if it has a wall wort see if it has power coning out if it they have a fuse in it and you cant replace fuse..................tom

Yes it has a transformer power supply (wall wart), but it still powers up, it just doesn't function properly - like the IC chip was damaged.

Did you run extension cords or backfeed your panel? Either way, that's a pretty small generator. Low voltage can damage electronics as much as high voltage/surges. I had to run on generator power for a full week. Unfortunately I failed to purchase a 30k to 40k generator like I wanted and had to run on only 11k of generator power. I kept things to a minimum and the only problems I have are about a dozen blown electronic items from the huge power surge I received about 30 seconds after my power went off. It acted like it was coming back on but my lights were really bright and my TV sets started smoking. I then lost all power for 7 days...............................

Sorry to hear about all your damage. I was running through a transfer switch. I've only used this generator a couple times in the past 15 years, except for this 4 day outage, so investing in a 11KW + generator doesn't make financial sense for me. I could go to the Hilton during an outage and still be money ahead.

.................. i have a high eff gas furnace, an i wouldn't dare plug it into a generator. i use a "kill-a-watt" to verify the voltage and freq coming out of the generator, but would rather do without than have to start fixing things.
heehaw

The whole purpose for me of having a generator is to keep the house warm in the winter during outages. We had very cold temperatures and it would have been miserable without the generator. I do have a Kill A Watt device and monitor the voltage and frequency. I was getting as low as 95 volts briefly during big load start ups and as high as 125 volts during steady running.

I appreciate the replies and would like to hear from anyone running a high efficiency furnace on a generator.

 

[Dargo]

I appreciate the replies and would like to hear from anyone running a high efficiency furnace on a generator.

My furnaces are 94% furnaces. I think you'd have problems with that small of a generator though. The low voltage drops could very easily kill their circuit boards. I consider my 11k of generator power as being way too small for my needs.

 

[440roadrunner]

All modern equipment, from something "as simple" as your TV or microwave, to you computer or camera gear, is sensitive to voltage spikes, noise on the line and other problems.

IF YOU CAN afford it, It would at least do the following:

Buy a great big UPS to act as a buffer between the genset and the sensitive equipment. You don't have to run everything through the UPS. Even the refrigerator, which PROBABLY has a microprocessor nowadays (mine doesn't) may be a risk.

Someone mentioned furnaces---and by the way as a former HVAC tech I would not have a variable speed blower system shoved up my air return--all now have microprocessor controls which just might be sensitive to poor power line quality.

CERTAINLY power anything of the nature of your TV computer, etc through the UPS

Consumers should be raising **** about this. Read FCC part 15 fer example which sets interferance standards, and which have recently been devastated along with the "BPL" (Broadband over Power LInes) controversey, ---the point being that "protective" regulations concerning these issues have been gutted and underenforced

 

[George2615]

A reading of 95 volts is about a 20% drop from 120V. Sensitive electronics like to see better regulation from a power source usually less than 10%. I'm sure your 4K generator has some sort of regulation but just doesn't have the tolerance you need. 4k is pretty small to run a house especially if you have a fridge / freezer, well pump, furnace, plus lighting that at some point may come on at the same time overloading the Generator creating a low voltage problem. Surge suppression protection is not what you need. You need less load or a larger generator. Excessive load on a small generator causes severe voltage and cycle drops which can harm sensitive electronic devices.

I upgraded from a 5K to a 10K generator a few years ago for the same reason. The 5K couldn't handle the load if all these items came on at once. I have monitored my 10K during power outages and found it to operate at less than 5% above or below each 120V leg and within 2% of 60 cycles measured with my Fluke meter.

To continue using your 4K generator and stay at closer voltage / cycle tolerances you need to cut back on the number of circuits (load) hooked up to it or buy a larger generator.

A UPS unit would help provide a steady voltage source as long as the generator is running. Once it stops, the UPS can only hold that voltage a short time and whatever is hooked to it must be shut down. I lost a computer hooked to a UPS due to a power failure while I was at work. As the UPS lost its source of power the voltage gradually dropped and the resulting low voltage burned out the computer supply. I no longer leave my computer on when I'm not home.

 

[LBrown59]

i retired 4 years ago, after over 30 years working on electronic equipment: i used some pretty expensive constant voltage transformers on a lot of equipment, with no problems, until i put a scope on the output of those transformers: they put out the worse looking wave i had ever seen. never had any trouble with the equipment that was powered by those things, but i did away with them anyway: i just could not see how it kept from damaging the equipment: that said, i don't run any of my electronic equipment with a generator: i have a high eff gas furnace, an i wouldn't dare plug it into a generator. i use a "kill-a-watt" to verify the voltage and freq coming out of the generator, but would rather do without than have to start fixing things.
heehaw

But but but; If you have to do with out then why in the world have a gen in the first place????

 

[Ken]

Retired from a power co. and during outages due to tornado or ice storms was always surprised at what customers thought was a large enough generators. They would add up the wattage and buy this size of generatyor to then load to twice its rating and wonder why the breaker kept tripping. A dairy man asked me to check his PTO 25K s/b gen. It used to do the job. Then he added larger milking stalls larger milk tank. more chillers. then a well larger pump.so had several 5 h.p. motors close to 150 amps of total load.
Convinced him to purchase a 60 KW gen and this last ice storm he lost power and had no problems with load. also had shut off all not needed power to stay with in limits.We forget how dependent we are on power until it is gone.
ken

 

[Travelover]

Thanks for the good comments.

On the subject of a UPS, it would seem that if used with a generator, it would not really provide any protection. My logic is that if it senses line voltage (now supplied by the generator) it would just bypass this power to the load.

I guess you could plug something like a furnace directly into the UPS and unplug the UPS from the generator, but it would take a really big UPS to run the furnace for any time and you'd need to keep recharging the UPS battery when the furnace cycled off.

 

[aczlan]

On the subject of a UPS, it would seem that if used with a generator, it would not really provide any protection. My logic is that if it senses line voltage (now supplied by the generator) it would just bypass this power to the load.

a decent UPS is also a power conditioner, it will "clean up" the power that comes into it, the highs get cut off and it uses the battery to bring the lows up to the proper voltage, IIRC, it wont fix improper hertz (ie: 50 hz instead of 60)

Aaron Z

 

[RonMar]

All the UPS's I now work with are switching type. The input is fed right thru to the output(with a little going to charge the battery) untill an over voltage or under voltage condition is sensed. That condition is usually one that exceeds +/- 10 percent of the normal 120VAC. If the voltage drops below about 108VAC, the unit switches to the battery powered inverter and disconnects the input power from the load. This is typical, but some come set with higher tollerances, or can be switched to higher tollerances if desired.

If not overloaded the inverter output should provide 120VAC. This switching occurs very fast(usually less than 1/2 cycle of 60HZ). The UPS continues to monitor the input power and when it returns to within specification, it re-connects the input power to the load and resumes charging the battery. I have 3 ups's in my home. One for the entertainment center, one for the computer and one for the pellet stove. They are great for short power failures and for momentary generator overload conditions. I only have 3KW available from my generator, but my largest load is also only a 2/3HP well pump that dosn't run very often. I will occasionally overload it though, and the UPS's protect the expensive equipment while this is happening. The Beeping UPS is also good for bringing my attention to an overload condition that I might otherwise be unaware of while on generator power.

If you are taking power drops down to 95VAC, your generator is too small to deal with your surge loads. This is especially true if they last long enough to see on a kill-a-watt meter. Your generator is probably fine for most of your normal emergency loads. My house on backup power typically pulls less than 2KW. That big pull from your furnace startup, or a combination of loads is pulling the voltage down too low. Get a bigger generator, reduce the load to within the capabilities of your existing generator, or put the critical items on UPS's. I have done the latter 2 of these to live comfortably within my 3KW limit.

To the gentelman who lost a computer power supply when the UPS exhausted it's battery, I would say you have a bad UPS. The UPS should have shut itself down when the inverter was no longer able to maintain rated output, just like it disconnected from line power when it was not receiving correct voltage from that source. Another issue could also be caused by a cheap UPS. A cheap UPS is probably not going to give a real good sine wave output. Switching power supplies such as those found in computers do not like square wave or modified sinewave outputs.

 

[heehaw]

"If you have to do with out then why in the world have a gen in the first place"
strictly for lights, frig and freezer: have gas wall heaters to stay toasty warm.
one thing i do plug into the generator thats electronic, the microwave: but then i have such a cheap one, i wouldn't fuss if it failed because of the generator: also use the washing machine, which has no electronic devices, electric skillet and toaster..not all at the same time of course: i only use a 3500watt generator:
also about losing a computer ps that was on a ups: most ups's come with software that can be loaded on your computer, so the computer will shut down properly as the ups battery goes down.
heehaw

 

[whistlepig]

All the UPS's I now work with are switching type. The input is fed right thru to the output(with a little going to charge the battery) untill an over voltage or under voltage condition is sensed. That condition is usually one that exceeds +/- 10 percent of the normal 120VAC. If the voltage drops below about 108VAC, the unit switches to the battery powered inverter and disconnects the input power from the load. This is typical, but some come set with higher tollerances, or can be switched to higher tollerances if desired.

If not overloaded the inverter output should provide 120VAC. This switching occurs very fast(usually less than 1/2 cycle of 60HZ). The UPS continues to monitor the input power and when it returns to within specification, it re-connects the input power to the load and resumes charging the battery. I have 3 ups's in my home. One for the entertainment center, one for the computer and one for the pellet stove. They are great for short power failures and for momentary generator overload conditions. I only have 3KW available from my generator, but my largest load is also only a 2/3HP well pump that dosn't run very often. I will occasionally overload it though, and the UPS's protect the expensive equipment while this is happening. The Beeping UPS is also good for bringing my attention to an overload condition that I might otherwise be unaware of while on generator power.

If you are taking power drops down to 95VAC, your generator is too small to deal with your surge loads. This is especially true if they last long enough to see on a kill-a-watt meter. Your generator is probably fine for most of your normal emergency loads. My house on backup power typically pulls less than 2KW. That big pull from your furnace startup, or a combination of loads is pulling the voltage down too low. Get a bigger generator, reduce the load to within the capabilities of your existing generator, or put the critical items on UPS's. I have done the latter 2 of these to live comfortably within my 3KW limit.

To the gentelman who lost a computer power supply when the UPS exhausted it's battery, I would say you have a bad UPS. The UPS should have shut itself down when the inverter was no longer able to maintain rated output, just like it disconnected from line power when it was not receiving correct voltage from that source. Another issue could also be caused by a cheap UPS. A cheap UPS is probably not going to give a real good sine wave output. Switching power supplies such as those found in computers do not like square wave or modified sinewave outputs.

You have gotten my curiosity up on the UPS. I know nothing about them. I This sounds like something I could connect to the pellet stove so my wife could keep the house warm until I got home from work to hook up the generator. I think the pellet stove draws about 200 watts. How would I know a good UPS from a bad one?

 

[Dargo]

Oh, while we are mentioning UPS and such I thought I'd mention what worked and what didn't work when I got a huge power surge. My two main computer systems on APC UPS systems survived with no issues at all. The computers, monitors and printers plugged into the APC UPS units received zero damage. If you have a Belkin surge protector you are just fooling yourself. Everything I had behind Belkin surge protectors got destroyed. They didn't protect at all. If you believe Belkin will pay on their "guarantee", just try calling them on it. They don't pay. It's almost like their guarantee is void if you had a power spike, which leaves me wondering why they call their items "surge protectors". While calling repair places each and every last one said that the APC brand of UPS are the only ones they see as working every time.

I wish I'd known this before I had the huge power surge! With my APC units I have the software that allows me to select the sensitivity and voltage ranges that are allowed to pass through. They also keep logs showing me how often and why they kicked in. I am always surprised at how often they kick in due to "electrical noise" even when I have no known power problems. That usually happens several times a week. I know APC units are expensive, but after I get past this terrible experience I am going to buy several more. If you have a big screen TV you better consider one. State Farm, like most insurance companies, now will only pay a maximum of $1000 for any TV that gets destroyed. Try to replace a high quality 52" 1080p 120hz LCD or plasma set for a thousand dollars. In general, you're gonna come up a couple grand short. Take that a couple of times and it makes the cost of the APC units not sound so bad.

 

[whistlepig]

Dargo,
That's good information on the surge protectors. I agree with you. Spending a few dollars more for the APC surge protectors would be worth it.

 

[BobRip]

Not to disparage others comments, but I have been running my computer (laptop), TV, radios, telephone, modem, and etc. off of my 5kw generator for many hours (100 or so) with no failures. Maybe I was lucky. Of course the laptop has it's own battery, so maybe that protects from the drop outs. I noticed that the Northern 5Kw generator had a graph with it and bragged about the good sine wave it put out. I wonder if it is better than some. I did see a major dimming of lights and shrinking of TV picture when I start my 1.25 HP well. I won't do that again without turning off stuff. But no damage occurred. The well takes a long time to come up to speed, so it drops the voltage from many seconds. What I am saying, it that the damage is not guaranteed. Of course with a high dollar furnace you want to be careful. I am thinking that the electronics on your furnace may reduce the surges that it generates on start up. This is called a soft (for slow) start. Talk to your furnace manufacturer. They might know something and can make recommendations.

 

[George2615]

Not to disparage others comments, but I have been running my computer (laptop), TV, radios, telephone, modem, and etc. off of my 5kw generator for many hours (100 or so) with no failures. Maybe I was lucky. Of course the laptop has it's own battery, so maybe that protects from the drop outs. I noticed that the Northern 5Kw generator had a graph with it and bragged about the good sine wave it put out. I wonder if it is better than some. I did see a major dimming of lights and shrinking of TV picture when I start my 1.25 HP well. I won't do that again without turning off stuff. But no damage occurred. The well takes a long time to come up to speed, so it drops the voltage from many seconds. What I am saying, it that the damage is not guaranteed. Of course with a high dollar furnace you want to be careful. I am thinking that the electronics on your furnace may reduce the surges that it generates on start up. This is called a soft (for slow) start. Talk to your furnace manufacturer. They might know something and can make recommendations.

Bob,
Its not the items you mention that cause problems running on a generator since they don't draw a lot of current. What causes problems is when a high current device such as a 220V well pump, freezer compressor, refrigerator compressor, or A/C unit come on they create a large current draw on a generator. A compressor from fridge/freezer/AC can initially pull over 20A on start up. Add that to the load the generator is already supplying and it causes an overload for a 4K unit. If the generator is not large enough to handle that load the output voltage drops below where it should be which is what you saw as major dimming of lights and TV picture shrinkage. Had your freezer or fridge started as the same time you would have probably tripped the 20A breaker on your Generator.