Generators and Electronic Furnace Controllers

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I live in St Louis and just got power back after losing it for four days for the second time in one year.
The first time was in the summer and was merely inconvenient. This time I had to have a way to keep the furnace running. I first borrowed a generator (3550w), but I started feeling bad about putting so many hours on someone else's unit and figured it was time I had my own so I went out and bought a Coleman 5000w with the Suzuki 10hp engine.
Problem (with both but more so with the new one) is that generator power is not clean enough for my new-fangled electronically controlled furnace (Trane hv-80). With the borrowed unit the board kept flashing an error code that basically indicated to replace the controller board. Fiddling around with it for a while and I was able to get it running. With the new one the glow igniter comes on and apparently causes enough of a voltage fluctuation to disrupt the controller board and I get a "check igniter" error code.
Do other people have these problems? Between the midwest and the gulf coast we certainly have plenty of people who occasionally have to run on generators and electronically controlled furnaces are pretty much the norm now. Is my Trane just being particularly fussy? Everything else we powered off the generators ran great.
Of course the "cover our ass" page of the generator manual suggests getting a line conditioner for just about anything that's not a light bulb. Do I really have to drop a few hundred more dollars on one of those just to get my furnace to run?
By the way, what convinced me that this was the problem was that the furnace fired right up when I temporarily ran it thought my computer UPS. The UPS alarm squalled like hell because it wasn't big enough, but the voltage as measured with my voltmeter held much better and the furnace lit up. It would be nice if I could isolate the power to run the controller board from those that pull major amps so I could just get a conditioner for that, but it looks like everything hooks straight to the board so I don't know if that can be done.
Naturally, four hours after I got the new generator running the utility company got our power back up. I would still like to get a handle on this before the next time.
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On Mon, 04 Dec 2006 22:43:05 GMT, "Rick Brandt"

grounded properly. The new stuff with circuit boards are very finicky when it comes to a good ground. Bubba
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Are you just talking about earth ground (rod) or does it need to be grounded to the safety ground in the house?
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Both. Of course, if you wired the furnace into your generator using a three wire cord (third wire being ground) that should take care of it.
--

Christopher A. Young
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wrote:

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I second that opinion. I live in an area of the U.S. which had an extended power outage affecting several hundred thousand homes earlier this year, and our climate is, like many cities in the Northeast, very cold in the winter. Many homes with high efficiency newer furnaces had generator incompatibilities, but inadequate generator grounding was an extremely common problem which caused many furnaces not to work properly.
It is not surprising that permanently installed generators like my Generac Guardian require an 8 foot long solid copper 5/8th inch diameter rod to be driven into the ground and bonded electrically immediately next to the generator.
Smarty
wrote:

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Well that's good to hear. The next time (knock wood) I'll hopefully have fewer problems. That'll be Murphy at work of course. Ameren claims these are the two worst storms in their history as far as customers losing power and they happened just a few months apart. Now that I'm prepared a little better my generator will likely just gather dust.
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I bit the bullet and installed the Generac after two extended outages without heat, light, etc. Even if I never need it, the peace of mind is worth the investment.....
Smarty

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Put some fuel stabilizer in the tank (Sta-Bil or something similar) and run it for a few minutes before you store it -- we failed to do that after the last time we used the generator about 2 years ago, and then last Friday when we needed it, we couldn't get it started. :-( Took apart the carb, cleaned it with solvent and then compressed air, reassembled... and all was well. But it's a pain in the neck that could have been avoided with a stabilizer in the fuel tank.
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Doug Miller (alphageek at milmac dot com)
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On Tue, 05 Dec 2006 00:21:35 GMT, snipped-for-privacy@milmac.com (Doug Miller) wrote:

Its like anything else. If it is used infrequently and is important, you need to put it on a schedule. It should be operated XX amount of minutes every week/month. You dont put your car in the garage, let it sit for 2 years and then expect it to run when you need to go get a pack of smokes, do you? Bubba
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I like to run em dry.
Also, for hard starts, sometimes some ether sprayed onto the air filter helps.
If you remove the spark plug and spray ether into the spark plug hole, you turn a $500 generator into a $75 hunk of scrap to sell on Ebay. A relative of mine had this happen.
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Christopher A. Young
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WD-40 has (at least it used to have propane) as the propellant...

With Stormy's 'help', just about anything is possible...
Next time, suggest simply dip the end of the spark plug into the gas tank and then quickly replace it.
--
SVL




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Christopher; That doesnt make sense... You spray ether or starting fluid into the carb, not the actual air filter. Putting it into the spark plug hole is an option but not normally taken.
What did they do to the motor?
Tom
Stormin Mormon wrote:

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The relative who had spray ether into the spark hole, it dried out the cylinder walls. The piston froze up. After breaking the piston loose with a large wrench on the flywheel nut, the motor was able to start up and run for about half second. Then it threw a piston rod.
Ether on the air filter delivers only vapor into the cylinder, much less likely to dry out the cylinder wall.
The generator was sold on ebay for about $75.
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Christopher A. Young
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Well, nobody said he had to spray the whole can into the engine. Just one little spritz will get 'er going if the spark is there (and timed correctly).

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The best solution is to run the carb dry by turning the gas off at the tank and letting the unit run until it quits. The other poster's advice about periodically running it is a good idea as well but you can get by with just starting it a few times a year. You do need to put stabilizer in the tank if you are going to leave gas in it for more than a few months. But even with stabilizer it will not last forever and eventually should be drained. I run mine twice a year and if I reach the end of the year and have not had to use it I drain the gas from the tank. I also keep a 5 gallon container of gas with stabilizer in it around. Periodically I use that gas in the lawn equipment and replace it with fresh gas and stabilizer. That way you are ready to go whenever. Usually you have some advance warning but not always. I've had mine for about 8 years now.
I have not had the problems you are having with your furnace though. One of my furnaces is newer but it too seems happy with the generator power. Make sure you have all three lines well connected. I back feed my main panel and it's always worked fine.
Doug Miller wrote:

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The main panel has a proper ground
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Yes, it does.
I'm wondering if he has tried to connect directly to the furnace with it disconnected completely from the main. Not just with the breaker off. In that case he probably does have a floating ground at the furnace. If you just turn off the breaker and connect the two hot and the common from the generator to the furnace then the main panel will give you an earth ground and tie the common and ground together. Not exactly the way you should do it but it should work and you would not have a floating ground.
There is a mechanical lockout available for several brands of main panels that works with one double breaker at the top of the panel and the main breaker. It mechanically locks out the double breaker when the main is on and then locks out the main when the double breaker is on. That lets you back feed a generator safely through the double breaker. I just take my two ac compressors and electric dryer breakers offline and then switch the rest of the house over to the generator. I have a 4400 and it runs everything pretty well. I have to instruct the rest of the houshold to turn off lights and things when they are not being used. I run computers, tvs, audio equipment, etc all without problems. Most elecronics has switching power supplies these days and they can handle some pretty trashy power. One winter ice storm we even kept the christmas lights running on the outside. But that is sort of rubbing your neighbors faces in it :-) Won't start my 2 ton upstairs ac compressor even with it as the only device powered up and the air handler fan off.
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jamesgangnc posted for all of us...

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Tekkie Don\'t bother to thank me, I do this as a public service.

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