Used generator

[drewmo]

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.

 

[Jags]

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.

 

[greg13]

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

 

[Gary_602z]

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

 

[begreen]

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.

 

[MasterMech]

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.

 

[jebatty]

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.

 

[btuser]

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.

 

[begreen]

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?

 

[Jags]

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.

 

[begreen]

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.

 

[drewmo]

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!

 

[btuser]

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.

 

[pybyr]

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)

 

[Highbeam]

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.

 

[BrotherBart]

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.

 

[Jack Straw]

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]

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.

 

[Jack Straw]

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

 

[Jags]

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.

 

[woodgeek]

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

 

[MasterMech]

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.

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.

 

[drewmo]

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?

 

[Jags]

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.

 

[BrotherBart]

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.