I just bought a Sears craftsman 2 stage 7 HP 60 gallon air compressor to work on my 78 vette with yesterday($499). Well after working all day to wire it in it works like crap!! What did I do wrong?
The motor runs but it continuously surges like its revving up and down then after a few minutes the motor will click off (some type of overheating device?)
It did run smooth for about 15 seconds once then shut off.
I originally had a 30 amp breaker in but switched to a 20. (instuctions were VERY vague but stated 15 amps OR 20 amps, would this make a difference?)
The compressor did not come with a cord so I had to attach one.
Any help would be appreciated!!!!

 

did you start using it when you first turned it on? Or did you break the motor in first? Mine stated clearly to run the motor with no pressure build up for about 10 minutes before using...just a thought

 

Yes it was during the break in procedure. It was revving up and down for about 7 minutes then automatically cut out.

I honestly dont know anything about compressors,I just saved up for one so I could sand blast and paint my frame on my restoration and now this

Of course I dont even know if this is normal or not?

 

Is it a 220 VAC unit? I assume so. i try to run mine in the garage, and it always pops the breaker. i hardly get any use out of it. my house is old and the electrical system sucks in it. The clothes dryer does the same thing. i took the compressor and used it at a friends house, and it tripped his breakers also and his house is new. It's a 110VAC Craftsman, so I don't know if they draw extra heavy current or what. So, in other words, I have no advice.

 

the motor plate should state the number of amps. are you runiing this as a 120 set up or 240? do you have good clean power with heavy gauge wire coming to the unit?

 

I am no electrician, but have wired a few compressors. Your compressor most likely requires a 220 volt service, did you buy a 220 or 2 pole, 20 amp breaker to wire it to? The manual should give you the general wiring requirements to get it going. More than likely if you wire it to run 220v it will need 30 amps not 15, but check out the manual. If the amperage is too low it may start but quit as you describe.

 

i was thinking that this sounds alot alike a motor that is not getting good clean power and it is getting off cycle....i would be using the 220 set up and make sure i had good clean power and the right size wires coming to it....

 

 

Thanks everyone,still working on it.

I wired it in using a dual 30 amp originally. thats 220 right? Although it states that its a 240 only? what does that mean?

The manual stated use a 15 or 20 amp so I switched the circuit to from a 30 amp to a 20 amp and still got the same thing.

The worse part about this is I took a week off work to work on my car and sears cant send anyone out til next friday! So I guess Im back to hand tools til then or til I figure this out.

 

Just curious. Did you run a dedicated wire from your main power box to your compressor? I hope you are wired for 220 volt. For one thing you did the right thing buying a 2 stage air compressor for a start but all 2 stage compressors that I know of use a 220 volt circuit and I hope you have it wired this way. You just didn't attach a power cord to this compressor and plug the unit into a standard 110 volt outlet did you??? Do yourself a favor on Sunday and drive over to your nearest Home Depot or Lowe's and talk to someone in the electrical department. They should be able to straighten you out. You can also cheaply pickup a basic electrical guide there showing you how to wire for 220 volts. Let us know how you make out. I wouldn't just wait a week for someone from Sears to come over.

 

let me first state that i am not a electrician.....but i do all of my own wiring......get a voltage tester from Home Depot made by klein....it will let you test for 110/120v as well as 220/240v....if you have 220/240....you need three of the same size wires going to the Unit plus a ground wire.....these should be like a#6,8 or 10 gauge wire depending on the length of the run so the wire will be like 8/3 with ground....or if you are using conduit they can be individual wires....it sounds to me that you have the wiring done wrong....i don't know if this a good explanation but you get the 220/240 by usng the distance between the two phases. you do have three big wires coming into your panel box right? and one goes to one side of the box and the other goes to the other side? and the third goes to a bar on the side or the bottom? you need to have a circuit breaker that hooks up to "both sides" .....

be real careful in the panel box.....you can stand on plywood to make it a little safer and an old rule of thumb is only use one hand to do any thing in the box this helps to prevent you from getting 240 volts going through each arm across the heart and sending you to heaven. this panel box and wiring in general can be very deadly if you make a mistake. good luck and if your in doubt pay an electrcian to do it.

 

with Bob you need to play it safe when working in the main panel box. Make sure you shut down the main power coming into the box with the main shutoff switch before doing any kind of work in there.

 

and remember those really big wires are always hot!

 

I have the 33 gallon, 120v. It kept tripping breakers as well, when it would shut off (after the psi was reached) or when I would try to switch it on.

I did a search on the 'net and came up with a review by someone that bought one and had the same problem. It was something with the switch.

I've kept using mine, it's a small inconvinience at the moment. I'll eventually just replace the cr@ppy switch...

 

That may not be true being the switch. I have a small 1-1/2 HP compressor in our attached garage that when cold starting it it will trip the breakers at the regular outlets. The problem here is the wiring brought into the garage is of the wrong gauge in other words wiring that was brought into the garage when the house was built was sufficent for lights and small tools like a drill or what have you not a compressor. In your case you are probably going to have to run a dedicated line out to your compressor. That is what we did in my pole barn for my 2 stage 5hp 80 gallon Black Max compressor and it never skips a beat. We have 220 volts coming right out of the panel box right to the compressor. Previously to the 1-1/2 hp compressor I use to keep a 3-1/2 hp compressor in the attached garage having the same problem. We also had to run a dedicated line to this compressor to be free from breakers being tripped.

 

I've got the 6.5 hp version of your 60 gal tank and its a 220 circuit. I ran mine several hours using a DA and it work great. As others have suggested...check your wiring before you burn the motor up by running it to slow!

 

I assume you followed the directions in the book pretty good, make damn sure you didn't hook it up for 208, which would be 3 phase commercial power, not available in a house, this would make the motor do all sorts of crazy things, a 7 hp motor will NOT ever run on 110volts, so doing a 10 ga wire size at MINIMUM and a 30 amp breaker is fine.....assuming everthing is copper wiring....don't use aluminum period......

so inside the motor assy, check the hookups, as it's hard to tell how they shipped it, you maybe have to change a few wires around, follow the directions, clearly, exactly....

GENE

 

When I first hooked up my compressor to 120, it would have problems starting and popping the circuit breaker. Found out the circuit I was using in the garage also runs my daughters room. Move it over to the other side on another circuit and it runs great.

 

OK heres what happen. when we wired the outlet we put the white wire in the middle and the black on one side and the ground on the other. Apparently it was only putting out 110 this way. We changed the black and ground and now 220! Compressor is working beautifully!

One other problem as I tightened the face plate down The screw cut into a power wire and when I threw the breaker it would shut down all power. It took a few minutes to figure out what I had done. I am an electricity moron.

Thanks everyone for all the help

 

good job .....