anyone know if i can convert this?

[91stranger]

So I got an old air compressor and it has a 220v motor on it. I checked the tag and inside it and it cannot be wired for 110v. So I need to know if I can convert this plug to either a 110v plug or if there is another way around this. I don't have 220 at my house so right now its just a big heavy paper weight. I had it sold and I told the guy since I couldn't test it for him that if he didn't want it I would give him his money back and he said it ran good but has a pinhole in the tank. my plan is to drill the pinhole and put a drain plug in. But I'm not going to do all that work if I cant use it at all.

 

[Denisefwd93]

So I got an old air compressor and it has a 220v motor on it. I checked the tag and inside it and it cannot be wired for 110v. So I need to know if I can convert this plug to either a 110v plug or if there is another way around this. I don't have 220 at my house so right now its just a big heavy paper weight. I had it sold and I told the guy since I couldn't test it for him that if he didn't want it I would give him his money back and he said it ran good but has a pinhole in the tank. my plan is to drill the pinhole and put a drain plug in. But I'm not going to do all that work if I cant use it at all.

Just get a new plug, they are made that way just so people don't make the mistake of connecting to the wrong voltage. they aren't expensive. you don't want to put a 120 volt plug on a 230 volt anything.

Switches Outlets plugs all have amperage ratings also I believe that's probably a 20 amp.

Unusual that amotor cannot be wired for 120 or 230. It is not likely you don't have 230 in your house. You just need a double breaker but if you don't know about electrical, best get somebody that does. Other option is just get another motor!

120 volt is usually one black wire and one white wire the black is hot to White is neutral not necessarily ground but sort of the same thing.

230 volt, basically both lines are "hot" a 115-120 Volt or 115 volt it gets confusing but you have 2 hot lines (also called poles or legs) they should both be black but you will almost always see a black and white because they used 110 volt wire. A proper cord or wire going to a 230-volt appliance will have two blacks and a white or a black, red, white and a ground,

https://www.stayonline.com/reference-nema-straight-blade.aspx

 

[lvwill]

I acquired a similar compressor quite a few years ago and just went to harbor freight and bought a 120 volt motor with the same size shaft and haven't had a problem since.

 

[Denisefwd93]

oh... did you take the cover off the wire connection box on the motor housing? on the end? that is were you would FIND the terminals to change the voltage. Looks like it's 120-230 on the plate.

 

[RonD]

220volts is not quite the same as two 110volt, although it is
And 115/230 or 120/240 is the same just different description of voltage levels on power grids

Pretty much all buildings are wired with TWO 110v lines that are out of Phase, and a Common line, so 3 lines come in from the Power Pole
Industrial buildings get 3 Phase, 3 110v lines and a common, 4 lines

So you do have 220v available, unless you added a separate fuse box with just 2 lines from the house, if thats the case get a 110volt motor

The house fuse box will have 2 phase 110v set up as every other circuit breaker as Phase 1 and in between Phase 2
Like this
Phase 1 110v
Phase 2 110v
Phase 1 110v
Phase 2 110v
Phase 1 110v
Phase 2 110v

And thats on both sides of the panel

So to get 220v you need a 110v from each Phase, so you need a double circuit breaker for the AMP rating on the motor, when you plug it into the panel it connects to Both Phases of 110v
Double breaker is just 2 individual 110v breakers hooked side by side, but if one "trips" it also trips the other for safety reasons

Then run 1 wire from each side of the double breaker and a common wire to the 220v outlet, and you have 220v power

220v is used because the wire size can be smaller for the AMPs required
Ovens/stoves and Cloths dryers are often 220v

 

[Denisefwd93]

Then there are industrial type buildings to use 480 and 277 lol,. And parts of old cities like Philadelphia have or had what is called two-phase but I didn't want to bring all this stuff up on a simple air compressor. Can you believe Ron with all this AC knowledge I have I'm still intimidated by 12 volt systems on cars and boats lol

 

[91stranger]

Here is the inside of the motor. Can anyone explain this a little better than the vague diagram on the back of the access plate. The motor does not say 110 capable on the data tag.

 

[Denisefwd93]

Here is the inside of the motor. Can anyone explain this a little better than the vague diagram on the back of the access plate. The motor does not say 110 capable on the data tag.

It CANNOT run on 120.

 

[91stranger]

It CANNOT run on 120.

That's what I figured. Now if I find a 110v motor will there be any changes that need to be made to the shut off switch in the box next to air compressor? I will probably end up saving the pump and junking/selling the rest.

 

[Denisefwd93]

That's what I figured. Now if I find a 110v motor will there be any changes that need to be made to the shut off switch in the box next to air compressor? I will probably end up saving the pump and junking/selling the rest.

On a 110 plug and receptacle the smaller prong is hot The Wider one is neutral.

The black goes directly to the switch. then the other side of switch black goes directly to the pressure switch.
the other side of the pressure switch gets a black directly to the motor.

If the pressure switch had two sets of contacts, just use one set of contacts for black

White from motor,connect the two whites together in the pressure switch and white back to the wide prong on the plug.

110/20 black is the power, (hot) all your switches (pressure or manual) will interrupt the black line only


white line completes all circuits and goes back uninterrupted to the neutral connection

 

[RonD]

And +1 to Denisefwd93 who knows electrical as well

 

[Denisefwd93]

And +1 to Denisefwd93 who knows electrical as well

aww thanks Ron!

when we rewired the battery banks on my large sailboat I was terrified!

 

[RonD]

A Healthy respect for electricity, in any form, is never a bad thing

 

[RonD]

Two 6 volt batteries, and a 12volt?

 

[Denisefwd93]

Two 6 volt batteries, and a 12volt?

Oh yes the two sixes were for the house Bank had 2, 12s but one was enough for the two cylinder diesel starter, also had a new isolated circuit battery switch 90 AMP alternator and automatic charging relay. 12 at Refrigeration in the icebox all set for cruising! then I sold the boat