My big 120 gallon air compressor stopped working recently. I haven't really bothered to look into it but it's 50ish years old so the tank is likely at the end of its service life anyway.

I'd forgotten that I had my grandfather's little 20 gallon air compressor from a few years back when he died, and I just today found it/remembered it in the shed (never go in there)

I'd like to use this little 20 gallon in the interim.

The compressor says it's wired for 230 volts. I have a 240 volt separate breaker setup in the garage that I use for my welders and (had been) for the big compressor. Problem is, I don't know what to do with the compressor plug (pictured above - it won't fit my outlet on the 240 volt breaker setup plus it's much too small).

Here is the compressor plug compared to my Hobart Handler 230v plug. Why is it so much smaller?



So, does anybody know what I can do here? Can I just wire on the different style plug? I guess this might be kind of n00bish, but I don't want to take any chances

 

There is an adapter for that, search a hardware store.

 

I went to Home Depot and could find no such adapter. The guy there sold me a 20A 250v single outlet.

Problem is, after getting home and looking around the garage, I don't have an extra/free wallbox/outlet to wire it into.

Do you by any chance know what this adapter is called or have a link?

 

Crap man I don't know what its called but I remember having one at the house that I never used and always found odd, if I can find it I'll ship it to you all you would have to pay for is the shipping.

 

Wow that's a really old style plug! My grandfather was an electrician and I remember about 20ish years back, he changed out all the outlets in the house that had that style plug. As far as I know, it's an obsolete design. Your best bet would talk to an electrician that's been around for a while and is familiar with this plug, and see if he has any recommendations for you.

 

You will not be able to find an adaptor for permanent use, cause reason for that plug is because it can only be used with a 20 amp receptacle (as you may know) and like most homes are today most are wired with 15 amp receptacles but if you get a 5-20r (receptacle) you can use that plug just like a regular plug cause it has the little perpendicular slot to it and also if installed make sure you have it wired to a 20 amp breaker too. And if you don't have any extra receptacles you can make a standalone box with one wired to a single 20 amp breaker. I hope this helps.

 

That's a 20 amp, 120V plug.

Adapter here...but then you're running a 20 amp device on a 15 amp circuit.

http://dealnay.com/243128/furman-adp...-amp-plug.html

 

^^^^^ exactly what I was talking about I for got the name of it great find man.

 

http://www.homedepot.com/h_d1/N-5yc1...atalogId=10053

$3 fix.



I've spent the last month or two fixing the mis-wired three and four way switches in my house, adding ceiling fixture boxes and tying them into existing wall switches, etc....sometimes I think I know the HD electrical department a bit too much!

 

After looking closely at the plug on the end of the compressor it says "20A 250v" so I guess that clears that up.

That's what the guy at Home Depot sold me. Well, he actually sold me a 20A 250v one that just has one receptacle as opposed to two

The problem is that I don't have a free outlet in the garage to convert to this receptacle.

Could I use that adapter you linked (great find BTW, that's the exact kind of thing I was looking for but couldn't find anything) and just upgrade the breaker to 20A? Or is that a big no no similar to putting a higher-rated fuse in a car because the smaller one keeps blowing?

Mista.. how involved/hard is it to make a standalone box with one wired to a single 20 amp breaker?

 

Well, if you look closely at the outlet in the pic, it'll take both the standard 15A plug, and your funkish 20A plug, so there's no need for a separate, dedicated plug.

I'm unsure as to the wiring requirements for a 20A service.....but I'm also unsure as to the real world current requirements of your compressor.

Swap the 15/20A outlet into your existing 15A service outlet box, plug the compressor in and see what happens...maybe have some 15A slo-blo fuses installed to absorb any minor current surge when the compressor starts.

For $3 and some minor fiddling, I'd start there.

 

If you're putting in a 20A receptacle, you'll also need to replace the breaker that's on that line with a 20A. Might be only a few buck depending on the panel, but you'd better be damn sure you know what you're doing. Mess that up and you're going to wish you hadn't when you get the bill from the electrician.

Be sure you know how to kill power going to the panel, (May be a breaker switch outside near your meter). The breaker has to match the panel, that's the real trick when it comes to cost. Some panels have $5 breakers, others have $40 breakers, both do the same thing, but work only in their proprietary box.

 

No you can't just use the adapter For constant use cause the wire gauge is too small for constant 20 amps going through it. These are only meant for small jobs nothing major.

 

if your breaker box is near not hard at all... Only thing needed is the correct gauge wire(with a ground) a standalone box( for a recepticle) and some conduit/plastic piping( rated for interior/exterior use, usually a grey pipe.) some fittings for the pipe( like elbows sleeves and connectors to connect to the breaker box) and of course the correct amperage breaker for your breaker box. Just run the single line in the pipe to your breaker box and wire it in. Hope this helps

 

A lot of old timers will call that a "hospital plug" because that was one of the few places you would find one in use. Like the others have said, that is for a 20 amp circuit.

First of all, look on the air compressor motor and verify that it is wired for 220/230/240 volts and not 110/115117 before you go any further. If you can change connections in the motor so it will run on 115 that's what I would suggest. If you use that white receptacle shown in post #9 and wire it to 220 volts, you'll have a short circuit when you turn the power on. On 110/115/117 volt receptacles, the neutral wire (silver screw) is connected to the ground screw internally. A 220 volt circuit uses 2 115 volt circuits, 180 degrees out of phase with each other. That's why the circuit breaker for a 220 volt circuit is made up of 2 circuit breakers, one for each of the 2 115 volt circuits. Also check and see if it really does need a 20 amp circuit because that plug looks like a replacement and maybe they went over-kill on it.

A 20 amp circuit should have 12 guage wire. A 15 amp circuit uses 14 gauge wire.

If you can run that compressor on 115 volts and your house uses Romex wiring, see if you can find a section that has the wire size/gauge printed on it. My house has 20 gauge wire going to the 15 amp outlets and a 20 amp circuit breaker because there are multiple outlets on one circuit breaker. Maybe you can get lucky and not have to re-wire anything.

I live in Plano, so pm me and we can discuss this over the phone or maybe you can talk me into making a visit.

 

Plug on left is a NEMA 6-50P, commonly used on welders. It is a 3-wire 240VAC (no neutral). This is a 50A 240VAC plug.

Plug on right is a NEMA 5-20P, which is a 20A 120VAC plug. Do not modify the plug to go into a 15A receptacle (NEMA 5-15R)!!!!