Electrical Advice Wanted!

[Beatles65]

I am needing some electrical advice on an old Air Compressor. I posted awhile back about purchasing this Sand-born air-compressor. Now that I have it home, I want to be able to use it! My friend who sold it to me had it wired directly into his box, but I want to be able to just plug it into the wall. There is no cord to use has he had it hardwired. The motor says that it is wired for 110 volts and requires a 30 amp fuse or circuit breaker. What is the correct plug in to use on this compressor? Also, do I need to put in a 30 amp fuse into the box to use it? Hopefully this makes some sense! I am still learning you know!

Thanks for all the Help Everyone!
Form Denton, Nebraska.
Andrew Kean

 

[Greg K]

A Leviton brand 30 amp 125 volt cord end plug # is 530-p. Any electrical wholesale house should stock what you need. If you check that plate on the motor and look at what says FLA or Amps and see if that number is under 20 then you can run 12 guage wire, if over 20 amps then run #10.

 

[wisbaker]

It says you need a 30 Amp breaker or fuse. I am not an electrician but it's pretty easy-the compressor says IT NEEDS A 30AMP CIRCUIT. This means your breaker and everything from the breaker to the motor MUST BE RATED FOR 30 AMPS. Probably don't want to put anything else on that circuit. So do you have a place in the panel for another breaker? If you're not familiar with electricity you might better hire an electrician, beats burning your shop down. To give you an idea the normal outlet on your wall is usually rated for 15 Amps. To wire this you'll need a 30 amp breaker, wire sized for 30 amps to run from the breaker to the outlet, a 30 Amp outlet, a 30 Amp plug and cord sized for 30amps to go from the plug to the motor.

 

[JRSutton]

Not to sound like a )(#*$# but it's really one of those questions that ... If you have to ask... call an electrician.

The actual work is easy enough to do yourself - but you really need to know what you're doing, CODE wise. And that's not always so easy.

Anyways - yes, you need a 30 amp breaker. You'll probably need 12 guage wire to the plug. And you'll need a special 30 amp plug in the wall - and from the compressor to the wall.

So I'm not sure how you meant it - but you can't just put a regular three prong plug on it and and plug it in anywere - it has to be that special plug that only fits that 30 amp outlet.

Again, easy enough to do, but if it's a simple cable run, an electrician is probably cheap enough anyways - so it worth letting them do it.

 

[Janicholson]

I agree with Greg below.
The distance to the box is also important. I would use the 10-3 wire if it is more than 10 feet.
Twist lock will do, but a dryer style would also be fine. Make all connections inside boxes. Circuit breaker boxes are far more convenient than fuses. If set up for 50 amp use it might do for a buzz box welder, or plasma torch! Jim

 

[Bob M]

Andrew - Looks like your motor can be reconnected for 240 volts. If so, and if you've got 240 volts in your shop, a 15 amp/240 volt circuit will do the trick.

Post a closeup of the wiring diagram on the motor tag (above the word "LEESON" in the lower right corner of the tag). The diagram will detail if/how the motor can be reconnected.

 

[teddy52food]

If there is a box where the wire goes in, remove the cover & see if there is a diagram to wire it for 220. It will run cheaper on smaller wires.

 

[Beatles65]

Here is a picture of the data plate on the motor. Would a dryer cord work? I know that the plug is set to a 30 amp breaker in the box. We also have an outlet in the garage that they put in because we told them we wanted to run a compressor. Would this plugin work?

Thanks everyone for the great replies!

From Denton, Nebraska.
Andrew Kean

 

[Pete in MD]

The motor label shows it can also be run on 230 volts and draw 11-1/2 amps.

Get an electrician to change the leads inside the motor to run it on 230 volts and wire up a 230 recepticle on a 15 or 20 amp circuit.

220,230 and 240 are close enough that you can use whatever your breaker panel provides.

 

[Bob M]

Good news! Your motor can indeed be reconnected for 240 volts.

Your dryer cord set and wall receptacle will work. But it may not be code legal.

 

[bingo]

Hey Andrew, ever lost your house and shop and everything you own in a fire????????? I HAVE, HIRE A ELECTRICIAN!!!!!!!!!

 

[paul]

That compressor needs 30 amps at 110 volts. It will _never_ work properly or safely with any standard 110v plugin you have anywhere. It would need thicker wiring in the walls, a special 30 amp plug, and a special 30 amp breaker.

That would be stupid to set up. You will _Never_ safely get this to work with a normal 110v plug in, wire, or breaker.

As the others have said, fortunately the motor can be rewired to 220v and then you can use it with any 30 or 50 amp 220v plug in.

To do the wiring, as someone elese said, if you have to ask perhaps an electrician or at least a friend or relative who has done this before should do the work for you. It is very hard to think of everything, and if we make one mistake explaining it, shocks, sparks, fire, or death could just possibly happen - we hate to be responsible for that. Both changing the motor to 220v, and installing the proper 220v breaker, wiring, and recepticle is not hard, but there are many little details that need to be watched for.

--->Paul

 

[Dieselrider]

Rather than a plug, why not connect it to a disconnect box with a knife switch that would allow you to turn it off and on without unplugging it each time? I also would wire it 220 volt and then directly into a disconnect. Then from the disconnect into your main panel. The people at your electrical supplier should be able to help with just what you need. Or, call an electrician and watch and observe just what he does and ask questions. That's how we learn. Good luck

 

[Ultradog MN]

They do make a 30 amp 110V plug and outlet.
It's called a crows foot.
All smaller campers use them.
I was able to buy both the plug and the receptacle at home depot when I added a box to plug my camper in.

 

[Stephen Newell]

Your compressor is made to run on 110v or 220v to make it more versatile for someone that has only 110v at the location where they need it. It would be far better for your electrical system and the compressor itself if you could run it on 220v. The motor would run cooler and would be less stress on the pressure switch. As far as the electrical service, you can't just change a breaker to 30 amp. If your wiring is done with a 12 or 14 gauge wire and you install a 30 amp breaker, the wire might burn up before the breaker trips. Normally 30 amp wire is rated for 10 gauge wire. With a compressor I usually go one gauge heaver than what it calls for. The constant use when you spray paint or sand blast puts a lot of demand on the electric service. You can also get better power if you would use stranded electric wire rather than solid wire. Without knowing how far you are from your main breaker box I won't guess at what gauge wire to recommend. Also you being located in Nebraska, I would imagine at times the compressor would be used well below freezing which is especially harder. It would be better if the compressor was hardwired but if that is not an option I normally use a range plug for a heavy duty applications.

 

[Anonymous-0]

Don't use the dryer cord/receptical for 120v! You need a dedicated 240v circuit for your compressor. What you appear to be considering doing you should not do! Please have it done right!

 

[John T]

OKAY first of all I would advise you to reconnect the motor leads to run it at 240 instead of 120 volts BUT EITHER WILL STILL WORK.

1) EITHER 120 or 240 will require 3 wires, for 120 its a Hot/Black a Neutral/White and an Equipment Ground/Green or Bare,,,,,,for 240 its 2 Hots/Black and Red and an Equipment Ground Green or Bare.

2) The motor should have a disconnection means in sight within 50 feet and a receptacle and cord with plug will suffice for that.

3) If you stay at 120 volts, you need a 120 volt 30 amp female receptacle and a matching 120 volt 30 amp male plug. (Any electrical supply house can provide both and many RV plugs and receptacles use a 120 volt 30 amp arrangement easily available at RV supply houses)

4) A 120 volt set up will require three 10 Gauge conductors from the panel to the receptacle and a 10 gauge flexible rubber etc cord with plug from the compressor to the receptacle.

5) A 120 volt set up will require a 30 amp single pole 120 volt circuit breaker and if such doesnt allow the motor to start up without tripping breaker you could use a 40 amp breaker

6) A 240 volt set up will require three 12 gauge conductors,,,,,,,,a 240 volt 20 amp 3 prong (2 hots & ground) receptacle,,,,,,,,a matching 240 volt 20 amp 3 prong plug,,,,,three 12 gauge conductors from panel to receptacle,,,,,,,,a 20 amp 240 volt two pole circuit breaker,,,,,,,,if that doesnt allow motor to start you can use a 30 amp 240 volt two pole circuit breaker

7) The motor should have thermal overload protection, such may be built in with a usually red resettable circuit breaker,,,,,,or external thermal overload protectors (heaters)

THAT ALL BEING SAID while a receptacle and cord with plug will suffice as a motor disconnecting means ID USE A WALL MOUNTED BLADE TYPE SAFETY SWITCH OR A WALL MOUNTED FUZED SAFETY SWITCH OR EVEN A COMBINATION STARTER A (IF THERES NO INTERNAL THERMAL OKVERLOAD PROTECTION). NOTE if you use a wall mounted fuzed safety switch you can use dual element time delay Class K5 fuses (20 amps if 240 volts 30 amp if 120) that will allow the motor to start

Then you need a flexible cord or flexible conduit running from the motor to the wall safety switch,,,,,,,,or a flex rubber cord from motor to wall mounted receptacle

SUMMARY

120 volt,,,,,,,,30 amp single pole 120 volt circuit breaker (40 if motor cant start without tripping breraker),,,,,,,,10 gauge wires,,,,,,,,120 volt 30 amp 3 prong receptacle and matching plug on the cord from motor,,,,,,,,or a wall mounted safety switch or fuzed safety switch with dual element time delay Class K5 30 amp fuse

240 volt,,,,,,,,,20 amp two pole 240 volt circuit breaker,,,,,,,12 gauge wires,,,,,,,,240 volt 20 amp 3 prong receptacle and matching 240 volt 20 amp plug on the cord from motor,,,,,,,or 240 volt two pole blade type safety switch or 240 volt two pole blade type fused safety switch with dual element time delay Class K5 fuses

GOT IT???????????????????

Hopefully the other fine gents can add to this for stuff I missed

John T

 

[greygoat]

I use a dryer cord set and recepticle for my
compressor! Haven"t seen the "Code Police"
around here in the 40 years that it"s been that
way!

 

[mkirsch]

Why would you use a DRYER CORD when the proper plug and receptacle are readily available at any box store or hardware store?

They're right there in the bins next to the dryer cords! Probably cheaper too.

1. Install a 30A, single-pole 110V breaker in your breaker box.
2. Run 10-2 Romex from the breaker box to the shop.
3. Install a receptacle box on the wall where you want the plug to be.
4. Install 30A rated 110V plug in the receptacle box.
5. Install matching plug and cord on the compressor.

The most difficult part is doing this without getting electrocuted while working in the breaker box. Most electricians will do this without turning off the main power, but you may want to.

220V (aka 240V) can also be done, but you will need to rewire the motor. If you don't have TWO ADJACENT slots in your breaker box, that can be a problem too.

 

[buickanddeere]

I don't know why you are insisting on 120V operation? No idea how to change the motor from 120 to 240v? Nor why you won't hire and electrician? Or why you want to mis-use a clothes dryer Plug & Receptacle ? Being cheap comes mind. It appears also most folk don't know the difference between over current protection and over load protection. Big hint here, the breaker or fuse in the panel does not provide both. 20 amp wire and connect the motor 240V. Use a 30 amp breaker in the service panel and set the thermal protection in a manual motor starter at 1.15 times full load amps.

 

[buickanddeere]

Properly wired with thermal protection set at 13.25amp in the motor starter, 30 amp two pole panel breaker and 12 gauge wire is fully legal and sufficient. I have a feeling however bubba is going to still wire it direct 120v to the panel with 30 amp wire and a 30 amp breaker . Then wonder why it doesn't work or prevent motor burnout.

 

[buickanddeere]

Rude, inconsiderate and dangerous to anybody else when you are dead, gone or incapacitated. I've seen and heard enough of bubba's home brew wiring.ever stop to imagine what happens when equipment is plugged into One half or double voltage?

 

[paul]

If he is thinking of using the drier cord for a 110v connection, I agree with you.

If he is switching the compressor to 220v, then I would think the drier cord and plug would be just fine? In a properly fused, wire sized, and so forth 220 setup. As he already has the cord and plug, I'd think that is the logical way to go, in fact?

Perhaps that is the confusion between some of us, we are assuming if using that cord he is going to run 220v? And you are assuming he is going to imporerly try to run 120v through that cord & plug and recepticle?

He needs to be real clear on the direction he is going, so he doesn't pick up the wrong advice and apply it in the wrong way.

--->Paul

 

[buickanddeere]

Odds are our intrepid home brew electrician won't bother running a white insulated wire only to the neutral lug, bare ground to the ground lug and line 1,line 2 to both the line lugs. Will make for problems when some poor smack plugs something else in the future expecting 120/240, neutral and a ground. I don' know why the guy is so insist ant on saving the price of a case of beer to do a half baked job.

 

[Stephen Newell]

You wouldn't catch me wiring that compressor with 12ga wire 110v or 220v. Anyway the way he wrote the post suggested to me that he was going to use the wiring that was already in the house that an electrician probably set up with a 20amp breaker and change the breaker only to 30amp. This is all I was trying to discourage. I'm guilty of filling in the missing blanks with my imagination. I still think where he's at in Nebraska he needs to go heaver. I have my compressor outside and when it gets below freezing it really struggles to get started. If I had more cold weather here I would have to upgrade the wiring.