View Full Version : Buying a used generator-What to do so you don't get burned!?
Ok, just looked at an Onan today (thanks here to whomever, Onan is what I want!!). Brother is buying it but I'm in charge because I 'know more about this stuff' which is basicly very little.
Looked at one that I knew I shouldn't have but did anyway, and I shouldn't have even looked. But here is what I gather:
-Compression check absolutely, no purchase without it. Check the plugs also (Greyish?)
-Load test if possible? (but these are not always ready for that, just have the 3 wires- how to hook them up quickly???)
-Make sure the thing is stored indoors (This one was outside, no cover that I could see, not kidding)
-Make sure the seller is not a complete idiot, this one sounded 'good' over the phone, but a complete.....you know.
-The oil/fluid catch pan had some old oil, is this normal? It was completely covered in crap.
That seems like minimum without freaking out the seller, anything else? Compression check, load test. What size plug on the compression checker?
The guy I went to was a complete moron, the thing was outside,(now its snowing) he kept whinning about how he had to sell it, yet it was all covered in backroad dust, years worth, and it didn't start when I looked at it today, (he thought it was a fuel-pump) I was pretty pissed off about wasting time and gas. But learned a bit.
gas? plugs should be cardboard brown
load test with known wattage, like a combination of space heaters or power tools.
Bring a multi meter and check all the plugs. 220 and 110.
oil could have leaked from topping it off, look for trails running down. Trace backwards from the pan/drips
maintenance records would be nice, along with it having an hr meter.
Cycle the breakers and make sure they work.
Ok,this was just pulled out of the camper. It was a clown show. Just 3 wires sticking out.
So, what do I need to bring to hook up the electrical. On this model (Onan 6.5) it was straight 220. How/what do I need to bring with to split it down to 2x 120? How to I set this test outlet up so I can tote it around? What components? Aligator clips or should I really wire it up and tape it for safety? (if it happens again.)
Find a better setup for slightly more. My onan is 110. 220 single and 3 phase diesel mil surplus 3kw. You can find em for under $1k
Had a 110/220 single Honda 5kw gas for $650 before the onan
Yea, I need to figure out how to split the 220, I guess its straight electrical stuff, just in case the next one isnt set up as a home generator. Some people may buy them to put back in their RV. Most of them are not set up for home use I've seen.
SideShow Bob
12-20-2013, 19:17
Ok,this was just pulled out of the camper. It was a clown show. Just 3 wires sticking out.
So, what do I need to bring to hook up the electrical. On this model (Onan 6.5) it was straight 220. How/what do I need to bring with to split it down to 2x 120? How to I set this test outlet up so I can tote it around? What components? Aligator clips or should I really wire it up and tape it for safety? (if it happens again.)
Don't walk away from something like this one, RUN ! Look for something to fit your needs, not something you will need to work on to get what you want.
Most generators made within the last 15 - 20 years will have GFI outlets on the 120 V side and a GFI breaker on the 240 V side. Go to Home Despot and pick up a GFI outlet tester ($15 - $20) cheap insurance when looking at used generators.
If a generator has been modified or Afro-engineered keep looking.
Ok, thanks- Not sure if you know about Onan, you have to add the outlets yourself because they are installed in RV's and such, so you get 3 wires or so. There are a few youtubes on how to do this. Yea, I would love to ad a GFI to this, I keep calling the place in Denver but cant get a call back or a pick up. The good American ones are made in USA and are from the 80's. They can last a long time if taken care of.
The RV this came out of had a blown something in the engine indicating probably did NOT keep up with the oil, which was a red-alert for me in the first place, but I ignored my own good advice. The guy turned out to be a real idiot, but it would have been great to get this on Youtube, on how NOT to buy and Onan generator. Pay me some $$ and I'll tell you the story, its worth a few bucks. If you can hear the 'flop flop flop' of giant clown shoes, run run run away.- Afro-engineered? Pagan-engineered on this one. Total goof. He was literally sucking on the fuel line, like he was giving it head when it wouldn't start. Should be on Youtube. He actually called back and said he was going to get a fuel pump for it. Flop flop flop...LoL I guess it was almost worth the drive.
Here is some redneck engineering. Sometimes the best kind!
https://www.youtube.com/watch?v=NQ0QybxOAaQ
I need to run about 20 amps minimum, so I need a 6.5 Owens, -I am calling around I need to speak to their service dept or something. The one I looked at only had 3 wires on it, he said it was 240, so Im not sure what it was, or what is going on with these models, or if you can even spit the 240 on them to 2x 120. I think I need an electrician for this because it may need a new circut breaker etc, I don't need any more big ugly surprises in my life.
Colorado Osprey
12-21-2013, 08:20
Ok, just looked at an Onan today (thanks here to whomever, Onan is what I want!!).
Your welcome
5 star RV- used camper parts usually has a few used ones in stock
-The oil/fluid catch pan had some old oil, is this normal? It was completely covered in crap.
Yes, this is normal. Most people spill when changing the oil or adding oil. I don't understand it but almost all RV generators have oil residue on the bottom of the housing/pan.
Ok,this was just pulled out of the camper. It was a clown show. Just 3 wires sticking out.
This is how they are made. They are designed to be installed in a camper--- hard wired.
Your three wires should be green (ground), black (hot) and white (neutral)
You do NOT have a 220 generator. If you had a 220 generator you would have 2 blacks, 2 whites and a green wire.
Which model did you get? Do you know how many hours were on it? Most of the Onan's RV-s are designed to run 10k hours before major service.
I didn't get it. But it had that setup, which is just the 120 I guess. As I said, this was a clown show. He said he was a 'mechanical engineer' or something goofy, and said it was 220. This was a good learning experience though. He said it had '120 hours', but who knows, the counter was 'still in the rv'. Etc. I walked away from it.
Yes, they are designed for campers but people have wired them for home use, as in that video. I have no idea how to do that, if I can do it, or if I need someone else to do it, when we get one of these.
Keep in mind that the general rating (steady state, not 'surge') is at sea level and when the unit was new.
A not insignificant loss in power at our elevations. Look around on line and you will find a horse power derate chart or calculator for non-turbo/super charged engines. Basically any altitude over 2000 ft starts to count. The manufacturers web page may have that information (it is also possible that the alternator/generator will be derated due to cooling being less effective as well). Give yourself as much as a 25% + fudge factor for power as a start.
And don't forget start up surge requirements (refrigerant/ac compressors for example). You might be surprised what they require (for a long life). Even florescent lamps have this issue.
brianakell
01-04-2014, 01:09
Find a better setup for slightly more. My onan is 110. 220 single and 3 phase diesel mil surplus 3kw. You can find em for under $1k
Had a 110/220 single Honda 5kw gas for $650 before the onan
Correct me if Im wrong.
3kw, in 220/3phase, and typical electric motor, say 3hp, wouldnt this only yield about 12 amps to the motor?
I need about 22 amps. The 4.0 and 5.0 are rated like 33amps and 40 something amps. Would I be safe at 9500 ft is the question with a 4.0?
Ok, is it possible to use a rheostat to lower the starting watts on power tools????I've used one with a hand drill. I guess I could get a Kill a Watt meter and see what happens.
SideShow Bob
01-05-2014, 22:44
A rheostat varies voltage. In resistive loads (incandescent lamps, space heaters.....) lower voltage = lower current.
However in motors (power tools), a lower voltage = higher current to maintain its rated load.
electronman1729
01-06-2014, 00:01
Correct me if Im wrong.
3kw, in 220/3phase, and typical electric motor, say 3hp, wouldnt this only yield about 12 amps to the motor?
a 3hp motor rated a 230VAC will yield about 9.6 amps. since you are talking 3phase you will need to divide by square root of 3 and divide by .8 for power factor and .8 for efficiency
How about using oxygen in the carb at high altitude 9500ft to get a 4.0 to be able to run a 16 amp motor?
jerrymrc
01-15-2014, 19:26
How about using oxygen in the carb at high altitude 9500ft to get a 4.0 to be able to run a 16 amp motor?
Ya might want to do a little search on adding 02 to the intake. [LOL]Not a wise idea. There is a reason why N20 is used in a controlled manner. [Flower]
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