# Used generator



## drewmo (Jun 7, 2012)

I'm going to look at a used 5000 watt Coleman generator tomorrow. Any advice on what to look for that would indicate either a good or suspect unit? Obviously I'll get it running and plug a few things into it. Other than that, not sure what I should do. Thanks for the help.


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## Jags (Jun 7, 2012)

Check the oil and look for color and smell.  It is not unusual for the oil to be dark, but you don't want it grimey and smelling burnt.

Basically if it starts easy, runs well and powers stuff, there is not a heck of alot more to check.


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## greg13 (Jun 7, 2012)

Don't forget to smell the generator side as well, you can smell burnt windings through vents.


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## Gary_602z (Jun 7, 2012)

greg13 said:


> Don't forget to smell the generator side as well, you can smell burnt windings through vents.


Take a glance at the guys other equipment if possible, it will tell you a lot on how he takes care of his stuff!

Gary


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## begreen (Jun 7, 2012)

I have that model. The fuel float can be a little fussy. Ours leaks gas with a full choke for some reason. It's a contractor generator essentially and meant to work under those kind of conditions. Jags summed up the checklist pretty well. Smell the electricals before running. If no telltale acrid electrical insulation smell, start it up and run. Put on your ear muffs first, it is not a quiet gen.


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## MasterMech (Jun 8, 2012)

Listen carefully to the generator side.  Bad rotor bearings will be very noisy.  If it's a Tecumseh engine on it, it's gonna be a noisy unit to start with.


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## jebatty (Jun 8, 2012)

The 5000 watt is a 240V (or 220V) generator? A pretty good test is to put a 1500 watt resistance heater on each 120V leg and let it run for a half hour. That's about a 1/2 load and should give a pretty good indication of what everyone else was saying to watch for. If you get it, do the same at least a couple times a year to make sure the gen will work when you need it.


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## btuser (Jun 8, 2012)

Listen for the revs too.  My old Coleman was a great genny but towards the end of it's 15yr life it started to drift between 107-118 volts.  You could hear the engine rise/fall a few RPM and watch the lights going dim/bright/dim/bright.   I'm not sure if it was  the AVR (automatic voltage setting) or something but if it wasn't running under  50% load it was a noticeable problem. 

Check it like a regular engine (smell, burn, sound etc) then check voltage with a meter on all outputs during idle + under load.


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## begreen (Jun 8, 2012)

jebatty said:


> The 5000 watt is a 240V (or 220V) generator? A pretty good test is to put a 1500 watt resistance heater on each 120V leg and let it run for a half hour. That's about a 1/2 load and should give a pretty good indication of what everyone else was saying to watch for. If you get it, do the same at least a couple times a year to make sure the gen will work when you need it.


 
Mine is a 240/120vac. I use it mostly in the 240v mode and am assuming drewmo needs 240 in France, n'est-ce pas?


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## Jags (Jun 8, 2012)

begreen said:


> Mine is a 240/120vac. I use it mostly in the 240v mode and am assuming drewmo needs 240 in France, n'est-ce pas?


 
I didn't realize that "Central Maine" was in France.  No wonder those people seem a bit goofy.


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## begreen (Jun 8, 2012)

Well, it's our closest state, lol. I am so confussed today. I had forgotten that Drewmo repatriated. Now about those violins on tv... Nevermind! in my best Emily Litella voice.


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## drewmo (Jun 8, 2012)

begreen said:


> Well, it's our closest state, lol. I am so confussed today. I had forgotten that Drewmo repatriated. Now about those violins on tv... Nevermind! in my best Emily Litella voice.


 
You might be confused, but that's a pretty big memory to keep that level of detail for someone who does more lurking than posting. Truth be told, these Central Mainers are a bit goofy. Great thing is I'll get to spend a couple of weeks each year in France, and the wife and kids will spend a good portion of the summer there. The cutest thing is watching the kids grow up bilingual, especially when they use one language when a word escapes them in the other. While my French is so-so, it'll be great to have a small army of translators very soon.

Thanks for all the advice on the generator. I sort of panicked last weekend as the rain fell and the water level rose in my basement. The sump pump earned its keep. We closed on a house recently and I like the idea of having a generator to keep some of the essentials going. Because of the advice here, I'm going to do a little more research before moving ahead with the purchase. 

Merci tout le monde!


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## btuser (Jun 8, 2012)

drewmo said:


> You might be confused, but that's a pretty big memory to keep that level of detail for someone who does more lurking than posting. Truth be told, these Central Mainers are a bit goofy. Great thing is I'll get to spend a couple of weeks each year in France, and the wife and kids will spend a good portion of the summer there. The cutest thing is watching the kids grow up bilingual, especially when they use one language when a word escapes them in the other. While my French is so-so, it'll be great to have a small army of translators very soon.
> 
> Thanks for all the advice on the generator. I sort of panicked last weekend as the rain fell and the water level rose in my basement. The sump pump earned its keep. We closed on a house recently and I like the idea of having a generator to keep some of the essentials going. Because of the advice here, I'm going to do a little more research before moving ahead with the purchase.
> 
> Merci tout le monde!


 
I've tortured myself with choice when it comes to the generator.  For me it came down to fuel choice of no nat gas.  If you've got NG, the an automatic standyby is cool.  Other than that I'll stick with the gas portable to keep the lights going.  I might change my mind when my parents get too old to sit in the dark.


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## pybyr (Jun 8, 2012)

Handheld hair dryers with variable speed are handy for testing generators, especially in combination with a voltmeter.

Grab or borrow a few and look at their wattage.  Make sure the total of however many you decide to hook up is about the same as but not greater than the rating of the generator.

Power one up and turn it up gradually and watch the voltage and listen to how the genset runs.  Then do the same with hairdryer #2, and so on.

If voltage starts sagging, rpms drop, or engine starts to sound like it is running badly before you get near the genset's rated continuous output, then something is suspect (which may turn out to be as small as a need for a tune-up, or something much bigger)


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## Highbeam (Jun 12, 2012)

The engines on these things are seldom a problem. It is the generator side. The output will be of improper voltage usually or just plain dead and they are generally disposable, cheaper to replace than repair. I did replace an AVR on my champion genset when voltage was getting too high and the company sent it to me for free!

Don't just plug in a single light. You have to load a genset to test it. Monitor voltage and load it as closely to the rated output as possible. Little heaters work great for this since they have no startup surge.


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## BrotherBart (Jun 12, 2012)

If you have a Kill-O-Watt plug it into the 120 outlet on the genset and then plug the load into it. I use one to adjust the speed and output on all of mine.


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## Jack Straw (Jun 12, 2012)

I know it takes a special meter, but I was told that the hertz should be checked, although I don't know what to do if they are off .


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## Jags (Jun 12, 2012)

Jack Straw said:


> I know it takes a special meter, but I was told that the hertz should be checked, although I don't know what to do if they are off .


The cycles will actually slightly increase (or decrease) as the voltage changes on most of these genny heads. It takes a pretty fancy unit to allow for the manual adjustment of the cycles.  I gave away my dual wave form O-scope many moons ago.


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## Jack Straw (Jun 12, 2012)

I used to have a hand held multimeter that checked hertz..... until I left the company


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## Jags (Jun 12, 2012)

Jack Straw said:


> I used to have a hand held multimeter that checked hertz..... until I left the company


Yep - digital O-scope  Fluke makes some nice multimeters that will do that.


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## woodgeek (Jun 12, 2012)

Kill-A-Watt reads Hz.  Every geek needs one.


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## MasterMech (Jun 13, 2012)

Jack Straw said:


> I know it takes a special meter, but I was told that the hertz should be checked, although I don't know what to do if they are off .


 


Jags said:


> The cycles will actually slightly increase (or decrease) as the voltage changes on most of these genny heads. It takes a pretty fancy unit to allow for the manual adjustment of the cycles. I gave away my dual wave form O-scope many moons ago.


 
Nothing fancy required.  I check cycles with an automotive multimeter (kill-a-watt or similar is fine too) and usually throw a tach on the engine just for giggles.  Adjust engine RPM to attain 60Hz under moderate load, should be pretty close to 3600 rpm.  The governor on my genny is adjustable but even if yours is not, bending the tab that anchors the governor spring should give more than enough adjustment if necessary.

Need something handy to load down a genset?  Most portable heaters are about 1500 watts and your wife's/girlfriend's/mistress' hair dryers are probaby between 1800-1900 watts.  Use all three if it's a big genny.


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## drewmo (Jun 13, 2012)

I can imagine the look on the seller's face when I show up with all the gear to test a $250 generator. He'll either suddenly change his mind and say the unit is not for sale or he'll cut a quick deal and say "$50 as is." Home Depot has a new Sportsman 4000-watt propane generator and a Powermate 3250-watt generator for $350 each. Do you think it's worth spending the extra $100 for something new, although I'd be giving up some wattage?


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## Jags (Jun 13, 2012)

MasterMech said:


> Nothing fancy required.


 
It takes "fancy" if you wish to adjust hertz _independently_ from voltage.  That was what I was trying to say above.  The genny head on my seriously old unit could do that (1942). It no longer has the original genny head.


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## BrotherBart (Jun 13, 2012)

If it looks clean like it hasn't been used much or abused, starts in a pull or two and will run a hair dryer I would buy it and haul it home.


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## begreen (Jun 13, 2012)

drewmo said:


> I can imagine the look on the seller's face when I show up with all the gear to test a $250 generator. He'll either suddenly change his mind and say the unit is not for sale or he'll cut a quick deal and say "$50 as is." Home Depot has a new Sportsman 4000-watt propane generator and a Powermate 3250-watt generator for $350 each. Do you think it's worth spending the extra $100 for something new, although I'd be giving up some wattage?


 
You have to answer that yourself. It depends on what you need to power, how frequently it will be used and for how long. If your area has 7+ day outages every few years then investing in a quiet reliable generator that is miserly on fuel is a good idea. If outages are infrequent and mostly a day or less then a less expensive generator may work just fine. Another thing to think about is service and parts. IIRC, Champion has a decent reputation in the less expensive gennys.

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/15131645.cfm


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## Highbeam (Jun 13, 2012)

Jags said:


> It takes "fancy" if you wish to adjust hertz _independently_ from voltage. That was what I was trying to say above. The genny head on my seriously old unit could do that (1942). It no longer has the original genny head.
> View attachment 68622


 
Modern generators have an adjustable pot AVR and you adjust the RPMs to get the hertz right. First do the hertz, then the voltage. No fancy equipment needed, just your standard kill-a-watt or multimeter.

For an extra hundred bucks I would buy new.


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## Jags (Jun 13, 2012)

Highbeam said:


> Modern generators have an adjustable pot AVR and you adjust the RPMs to get the hertz right. First do the hertz, then the voltage. No fancy equipment needed, just your standard kill-a-watt or multimeter.
> 
> .


 
kool - I didn't know that.  Do all of them have it?


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## BrotherBart (Jun 13, 2012)

I have a 5,000 watt genny that I bought at a landscape company's bankruptcy auction for $165. A couple of people commented later that they wouldn't touch it because they didn't have a chance to test it. I replied that the eight gallons of gas in it was a nice leveling factor.

The thing has run this house through three seven day outages and one four day one.


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## velvetfoot (Jun 13, 2012)

BrotherBart said:


> I have a 5,000 watt genny that I bought at a landscape company's bankruptcy auction for $165. A couple of people commented later that they wouldn't touch it because they didn't have a chance to test it. I replied that the eight gallons of gas in it was a nice leveling factor.
> 
> The thing has run this house through three seven day outages and one four day one.




You sound like you collect generators like I do.  
Last small outage we ran the Harbor Freight 700 (or whatever) watter.  Kept the food cold and lit a few lights while we watched TV.  
Maybe because it was raining, and I could carry it  under the front porch.  Or maybe just because it could!


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## MasterMech (Jun 14, 2012)

Jags said:


> kool - I didn't know that. Do all of them have it?


 
Only the expensive ones.  I have my BIL's Honda EM2200X in the shop right now (carb issues) and it has the adjustment for the AVR but that's not something I've seen on the majority of portable generators out there.  I'm not real picky with voltage anyways.  115V +- 5v is pretty standard anywhere in the US.  If the Genny is throwing out 116V at 60Hz, I'm not gonna get upset.


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## Jags (Jun 14, 2012)

MasterMech said:


> 115V +- 5v is pretty standard anywhere in the US. If the Genny is throwing out 116V at 60Hz, I'm not gonna get upset.


 
Zactly.  Basically anything from 110-120V is considered acceptable from your power company.  Below 110 is a no-no.


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## semipro (Jun 14, 2012)

jebatty said:


> The 5000 watt is a 240V (or 220V) generator? A pretty good test is to put a 1500 watt resistance heater on each 120V leg and let it run for a half hour. That's about a 1/2 load and should give a pretty good indication of what everyone else was saying to watch for. If you get it, do the same at least a couple times a year to make sure the gen will work when you need it.


 
I like to turn off the petcock and run the carb dry after testing. 
Use of a fuel stablizer is a good idea too.
And close the vent on the gas tank cap if you have one to prevent fuel evaporation.


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## Highbeam (Jun 15, 2012)

MasterMech said:


> Only the expensive ones. I have my BIL's Honda EM2200X in the shop right now (carb issues) and it has the adjustment for the AVR but that's not something I've seen on the majority of portable generators out there. I'm not real picky with voltage anyways. 115V +- 5v is pretty standard anywhere in the US. If the Genny is throwing out 116V at 60Hz, I'm not gonna get upset.


 
Not so fast, even the cheap champion gensets have an adjustable AVR. These are extremely common and cheap. You'll find that several companies have bought and rebadged the same chinese genset. The whole AVR is about the size of a smart phone.


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## wahoowad (Jul 2, 2012)

Tomorrow is day 4 of my current power outage, each day has seen temps of 99 or higher. I expect a couple more days to go with same temps. You can not predict the situation you will find yourself in when the power goes away. New baby, sick kid, aging parents visiting, pets that would suffer in the heat. Get a good generator. You knows that feeling you get when you stand back and look at your woodpile when you get 2 years ahead...that feeling that says you've done the right thing and you feel prepared...you get that feeling when you wheel the generator into your garage or shed and you don't give a crap how much you paid for it. When you need it and have it you feel like a freaking genius and your wife will look at you like you are one too.

I am on my 5th prolonged power outage in 5 years. 3 super hot summer outages and 2 winter storms. I am getting a 2nd generator, possibly a smaller one as a backup or to augment what I have now. I see limited downside as I can always sell it used for enough to justify a couple years usage. My current Champion has been a workhorse and served me well. Maybe I will simply buy another one just like it.


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## semipro (Jul 3, 2012)

wahoowad said:


> Tomorrow is day 4 of my current power outage, each day has seen temps of 99 or higher. I expect a couple more days to go with same temps. You can not predict the situation you will find yourself in when the power goes away. New baby, sick kid, aging parents visiting, pets that would suffer in the heat. Get a good generator. You knows that feeling you get when you stand back and look at your woodpile when you get 2 years ahead...that feeling that says you've done the right thing and you feel prepared...you get that feeling when you wheel the generator into your garage or shed and you don't give a crap how much you paid for it. When you need it and have it you feel like a freaking genius and your wife will look at you like you are one too.
> 
> I am on my 5th prolonged power outage in 5 years. 3 super hot summer outages and 2 winter storms. I am getting a 2nd generator, possibly a smaller one as a backup or to augment what I have now. I see limited downside as I can always sell it used for enough to justify a couple years usage. My current Champion has been a workhorse and served me well. Maybe I will simply buy another one just like it.


 
We're in the same situation in our part of Virginia.  We are running a gennie when well water, refrigeration, or fans (for sleeping) are needed but I really hate the noise, cost, fumes. 
I've been considering installating a PV solar system with battery backup for a while.  That idea is quicklly moving to a much higher priority.
I'm thinking of one at least larger enough to provide water, light, refrigeration, and fans.  With all the sunlight we've had during this event we'd be set, at least this time.


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## velvetfoot (Jul 3, 2012)

A little fuel sipping genny like the HarborFreight 2 stroke can do that.


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## btuser (Jul 3, 2012)

I looked into a monster genset to run the whole house but by the time you spend all that money you've still got to pay to run it. 2 gallons of propane/hr is more money than a hotel. I like the little genset that keeps the lights on, the heat + well water going and the fridge cold. About 1/2 gallon of gas/hr or less.

I'm a little worried about my folks if I can't get home right away to roll it out and get it going. The one big advantage with a stand-by genset is the automatic transfer switch.


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## karl (Jul 3, 2012)

Two things.  Seriously consider converting it to natural gas if you have it.  It's the equivalent of a little over a $1.00 gallon gasoline.  Consider converting it to propane if you have it instead of natural gas.  It's a little more expensive that gasoline right now.  A little less other times.  The big thing is that the engine lasts longer, the fuel doesn't go bad, and you don't have to try and find it during a power outage when the gas station pumps aren't working.

Second.  Figure out how much power you really need.  Obviously 220 and large if you want to run central air, but my 3000 continuous 110 runs everything I need including two window AC.  I might have to turn one off if I want to dry my hair use something else big, but I am saving on fuel with the small one


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## btuser (Jul 4, 2012)

no gas.........


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## Highbeam (Jul 5, 2012)

I have found and recommend the smallest 220 volt genset you can get. This allows you to backfeed your house to run refers, the well, and whatever else may be on the two 110 "phases" of your home's panel. If you don't backfeed with 220 then you will need to run extension cords all over the place and those bring all kinds of additional hazards.

So the now legendary champion 3500/4000 surge genset is 220 volts and only a 6.5 HP engine. Runs an easy 12 hours on less than 5 gallons of gas. Mine only cost 250$ and can be carried around by me (I only weigh 160) when full of fuel.  

You will have to determine whether the 3500 watt rating can run your stuff. If you decide you need 5000 watts then you take a fuel consumption penalty. Champion sells larger gensets.

I only wish that the big name inverter gensets like Honda and Yamaha were available with 220 volt ouput, and smaller fuel friendly engines.


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## tomc585 (Jul 5, 2012)

Highbeam said:


> This allows you to backfeed your house


 oh man....dont say that out loud. Lineman hate when people do that and for good reasons. When spotted they will cut the drop lines to that house and you will be required to have an inspection done and you will be restored last. Remember, a proper transfer switch is the only way most power companies allow generator use.


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## velvetfoot (Jul 5, 2012)

I have a SquareD lockout on my generator 240 feed.
The large generator can power the well pump.
However, I also power the house through the same 240 inlet with 120 from smaller generators.
I rigged up a plug that feeds both legs.  
Won't run any 240 volt appliance, of course.
Also, I believe, you maximize the utility of the 120 volt generator, since you don't have to be concerned about balancing legs.
Seemed to work during several outages.


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## MasterMech (Jul 5, 2012)

Highbeam knows what he is doing but it's still a bad idea to publicly recommend backfeeding.


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## Highbeam (Jul 6, 2012)

MasterMech said:


> Highbeam knows what he is doing but it's still a bad idea to publicly recommend backfeeding.


Thanks for the confidence Master but I assure you, there are legal ways to backfeed your panel. In my case, I used a whole house generator panel that includes an interlock tab to guarantee safe and legal backfeeding of the panel. *Shame on anyone for assuming I was backfeeding using an illegal method.*

You need to realize that there are legal ways to backfeed your system. Mine is UL listed, NEC approved, and the electrical inspector approved the install. I have a green sticker. I absolutely publicly recommend backfeeding the panel. It is a wonderful way to go.

I suppose it is possible to feed power from a single 110 generator to both sides of the panel by wiring the inlet plug in a nonconventional way. Not sure what that would do to the neutral line, seems that the single neutral will now be carrying double the load since the two normally out of phase sides of the panel are now in phase. Wouldn't want to overload that neutral.


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## begreen (Jul 6, 2012)

If there are no 240v loads, one can also just back feed just one side of the bus with a 120v genny.

Shame there aren't more 220v options sold here, they are common in many parts of the world, but you need to be sure it's 60Hz and not 50Hz that's used in Europe.


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## MasterMech (Jul 6, 2012)

By backfeeding the panel I was referring to the method most commonly employed by those who think they are above protecting the safety of others.  A double male ended extension cord plugged into a receptacle.  Or any other method that doesn't involve a code approved interlock device or transfer switch.


Highbeam said:


> You need to realize that there are legal ways to backfeed your system. Mine is UL listed, NEC approved, and the electrical inspector approved the install. I have a green sticker. I absolutely publicly recommend backfeeding the panel. It is a wonderful way to go.


 
I do realize there are legal ways of doing this but usually when an individual has gone to the effort to do it right, he/she makes that very clear. 

My apologies if I offended you.


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## velvetfoot (Jul 6, 2012)

I'm not sure how I'd be overloading the neutral.
It's feeding into a (as I recall) 40 amp breaker.


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## tomc585 (Jul 6, 2012)

MasterMech said:


> My apologies if I offended you.


and mine as well.

People also need to be reminded that not all cicuit breakers provide protect in both directions.


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## Highbeam (Jul 6, 2012)

No problem guys. Just terminology.

It is possible to backfeed the whole panel with a single 110 volt genset. You can choose to only feed one buss or you can "jump the hots" to feed both busses 110 volts "in phase". This is a problem for the neutral wire when you have any Multi Wire Branch Circuits and also a problem for the neutral between the genset and the panel.

On the 4 wire circuit between the genset and the panel: With normal balanced 220 operation the neutral carries no load, the out of phase legs cancel each other. When you feed 110 volt power in phase to both sides of the panel, every bit of that power (the sum of both legs) comes back on the neutral. You'll notice that the neutral in a 4 wire conductor is the same size as the hots so you must only load the hots to 50%.  

Everything is fine so long as you size the genset to not overload the neutral. This means only running 30 amps of 110 or 220 through a 10 gauge circuit.

I doubt it is legal.


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