# Convert air compressor from 240 to 110?

• posted on October 10, 2007, 9:28 pm
I have a Sears air compressor that is 240 and uses a different plug. It's a PITA because I have to add a new (240) outlet to every house I move to. Can I simply convert the motor to 110? How difficult is this? Or do I need to buy a new compressor?
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• posted on October 10, 2007, 9:38 pm
If the motor is dual voltage, which it will say on the name plate, you can convert it. However whatever the amperage draw is at 240 volts will be double at 120 volts, which pretty much means you'll need to run a dedicated circuit anyway
<dan> wrote in message

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• posted on October 14, 2007, 3:59 pm
RBM wrote:

Thanks all! After having an electician look at the compressor, it looks like I just need to buy (eventually) a 110v compressor.
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• posted on October 14, 2007, 8:02 pm
On 14 Oct 2007 15:59:10 GMT, "dan" <> wrote:

You must move very often....... With that said, why dont you just take the outlet with you when you move? It's not all that hard to add a dual breaker, piece of wire and an outlet in a box, assuming this is in an open garage. Surely not worth buying another compressor if that one works. Besides, 240 motors are much more efficient. From experience, I found that many 120v compr... wont start in cold weather, while a 240v one will.

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• posted on October 10, 2007, 11:11 pm
dan wrote:

Tell us the (real) horsepower of the motor or how many amperes it draws at 240 vac and lots of guys here will be able to give you a more definitive answer.
My guess is that unless you imported a small compressor from somewhere where 220 or 240 is the standard "household voltage" it's probably got such a large motor that you'd be hard pressed to run it off a 120 volt 20 ampere circuit.
I said (real) in my first paragraph because more often than not the advertised horsepower of air compressors and vacuum cleaners is exagerated hype. They use some stupid "peak horsepower" measurement of the energy the motor puts out when they apply a load which is large enough to cause it to stall.
Jeff
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Jeffry Wisnia
(W1BSV + Brass Rat \'57 EE)

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• posted on October 11, 2007, 12:53 am

Agree. Some motors are dual voltage and you can alter the connnections. But motor will take at least twice the current on 120. Also the starting curent of a 2 HP motor, for example will/may be much higher than when 'running'. My neighbour modified his dual voltage bench saw motor from 240 to 120. But encountered a) A lot of voltage drop on 120 volts and b) The circuit breaker would sometimes trip. Had to suggest to him that he install a a 240 outlet and convert back to 120 volts.

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• posted on October 10, 2007, 11:54 pm
<dan> wrote in message

You move that much?!
Some 240v motors can be changed; others can't. Normally they will give amperage for both 240 and 120v if they can. There are exceptions; my 2hp dust collector says it is 240v only, but I opened it up and found the conversion was simple. I called the manufacturer about it. They recommend 240v only because 120v will lead to excessive voltage drop.
So, if it doesn't show it as being 120/240, check the 240 amperage. If it is 9a or more you probably wouldn't want to run it on 120v even if you could. If under, it might be worth digging further.
(I did convert the DC to 120v, putting it on a 10 gauge multiwire circuit; so excessive voltage drop)

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• posted on October 11, 2007, 12:57 am
how 'bout quit moving?
s
<dan> wrote in message

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• posted on October 11, 2007, 10:09 pm
Steve Barker LT wrote:

Maybe he can't, because......
"It's time to change partners again!"
Which is a line from the song "Alma" by Tom Lehrer:
http://members.aol.com/quentncree/lehrer/alma.htm
and
http://home.comcast.net/~jwisnia18/temp/Alma.mp3
Jeff
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Jeffry Wisnia
(W1BSV + Brass Rat \'57 EE)

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• posted on October 11, 2007, 1:36 am
Check the motor nameplate to see if it can be run on 110.
I had a fella give me a old Sears (Simpson, Sears, and Roebuck, as a matter of fact) compressor mounted on a green horizontal tank, he said it just made a funny humming noise. It had a black motor on it, 240 only - not a dual voltage motor. Sure did hum funny on 110. I happened to have a dual voltage motor. I prefer them on 110 because so many places I work don't have 220 handy.
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______________________________
Keep the whole world singing . . . .

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• posted on October 11, 2007, 1:51 am
<dan> wrote in message

Not enough info. What size motor? Larger ones will take to many amps to run on 120 so you may need a dedicated circuit anyway.

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• posted on October 11, 2007, 2:08 am
On Wed, 10 Oct 2007 21:28:55 +0000, wrote:

Don't move so much!

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<%-name%>
• posted on October 11, 2007, 2:25 am

buy a new 120 volt compressor

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• posted on October 11, 2007, 2:54 am
On 10 Oct 2007 21:28:55 GMT, "dan" <> wrote:

If this is bigger that 1HP you won't be using 120v. Why not put a dryer plug on it. Everywhere has a dryer receptacle. You can generally use a breaker 2.5 times the FLA of the motor per 430.52 if it is internal overload protection.

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• posted on October 15, 2007, 4:31 pm
On 10 Oct 2007 21:28:55 GMT, "dan" <> wrote:

Chester Arthur Stiles, is that you?