PORTABLE AIR COMPRESSOR AND GENERATOR?

[Highbeam]

Despite all of the above information from reputable folks, my generator (coleman 11hp 5550 continuous/6850 peak) has no problem running or starting my typical 5 HP/20 gallon horizontal tank compressor. Could it be that the cheapy direct drive oilless air compressors use a chop saw type motor when the better compressors use an induction motor?

Remember that only half of the typical 220/110 volt capable generator's rated output is available on each of the 110 volt legs.

I think your trouble is with the CB on the generator.

 

[escavader]

So - long story short, is your breaker "arc fault" (different than GFI).

IM not sure what this means.I do have some electrical ability though.The compressor works fine at home,its using it with my 5500 watt generator is where it wont start up.So how could i rig up the generator to make it run,or could I ?About all i can tell you is there is a reset button i have to push,can i bypass it somehow and use some other type of overload protecter?Thanks all for the replys,my dads at the VA hospital,and ive been burning the mid nite oil.
ALAN

 

[BobRip]

IM not sure what this means.I do have some electrical ability though.The compressor works fine at home,its using it with my 5500 watt generator is where it wont start up.So how could i rig up the generator to make it run,or could I ?About all i can tell you is there is a reset button i have to push,can i bypass it somehow and use some other type of overload protecter?Thanks all for the replys,my dads at the VA hospital,and ive been burning the mid nite oil.
ALAN

Sorry about your dad. Could you convert the compressor to 240, or does your generators have a 120 only mode?

 

[escavader]

Sorry about your dad. Could you convert the compressor to 240, or does your generators have a 120 only mode?

HELLO,
I looked this up in the manual,it only says 120 volts.DADS home tonite,doing better.I am so glad there are Veterens hospitals for our soldiers ,who haved served our country.Any politician who trys to cut the benefits will lose my vote.It is wonderful,to visit there ,and listen to the storys they tell.Iam proud of dad,and all of our veterens,and current soldiers serving our country, and keeping us free.Sorry getting off topic
It looks like I need a bigger generator or a smaller compressor.
ALAN

 

[simonmeridew]

You may find that your generetor is not actually generating at 120 volts, it may be as low as 105 volts. This will cause appliances and motors draw more amps especially to start because they are striving to work at the rated wattage. Get a relatively accurate voltmeter, calibrate it by plugging it into your house outlet to see what the voltage is where you know the compressor starts and runs OK. Then check the running voltage on your generator with no load--nothing plugged in it--then see what the voltage does when you plug in the compressor. I betcha it drops down out of sight, maybe to 80 to 90 volts as it tries to start the compressor. The formula for wattage says that for the wattage to stay the same, amps have to increase if voltage decreases.
OK what to do about it. You said that your compressor is rated 120/240 volts. So it's super easy to rewire the compressor for 240 volts. If you run it at 240 volts the wattage of course stays the same but the amps DROP IN HALF. Problem solved. Just take the cover off the little plastic box that the line cord runs into on the compressor. There should be a little diagram showing how to change the wiring around with a couple of bayonet tap connectors. With my compressor I kept two different line cords one 120 volts and one 240 volts,The 240 volts oneI put a straight plug or whatever plug you need to plug into the generator 240 volt outlet. Compressors run better at 240 volts anyway if you need to use any kind of extention cord because you get less apparent voltage drop at 240 volts.
Synopsis: check your voltage and change the compressor to 240 volts.
simonmeridew

 

[_RaT_]

You may find that your generetor is not actually generating at 120 volts, it may be as low as 105 volts. This will cause appliances and motors draw more amps especially to start because they are striving to work at the rated wattage. Get a relatively accurate voltmeter, calibrate it by plugging it into your house outlet to see what the voltage is where you know the compressor starts and runs OK. Then check the running voltage on your generator with no load--nothing plugged in it--then see what the voltage does when you plug in the compressor. I betcha it drops down out of sight, maybe to 80 to 90 volts as it tries to start the compressor. The formula for wattage says that for the wattage to stay the same, amps have to increase if voltage decreases.
OK what to do about it. You said that your compressor is rated 120/240 volts. So it's super easy to rewire the compressor for 240 volts. If you run it at 240 volts the wattage of course stays the same but the amps DROP IN HALF. Problem solved. Just take the cover off the little plastic box that the line cord runs into on the compressor. There should be a little diagram showing how to change the wiring around with a couple of bayonet tap connectors. With my compressor I kept two different line cords one 120 volts and one 240 volts,The 240 volts oneI put a straight plug or whatever plug you need to plug into the generator 240 volt outlet. Compressors run better at 240 volts anyway if you need to use any kind of extention cord because you get less apparent voltage drop at 240 volts.
Synopsis: check your voltage and change the compressor to 240 volts.
simonmeridew

He mentions the compressor is 120V only which is typical for small portable compressors. If he cannot start the com-pressor with no air in the tank, the generator simply cannot develop the power necessary to start this electric motor.