Air Compressor Wiring Problem...

[at]

Hello All... I recently bought a 2HP (running) 25gal Craftsman air-compressor. I had an electrician come out last week and hook me up w/a designated circuit. He installed a 20a breaker w/ one 15a dual receptacle.

Yesterday I fired the thing up -- and in the first half-hour I tripped the breaker

3 times! While resetting I noticed that my *pro* had used an old 20a breaker instead of the new one he charged me for. I confronted him and he said that it shouldn't make any difference. I pressed him further and he made excuses ("Breakers never wear out..." Blah, blah, blah."You couldn't tell me what you were running so I used what I had at the shop...")

Now, he's just a kid and so I'm willing to cut him some slack. But the bottom line is I'm not sure he or his work can be trusted completely. The thing is whether I decide to call him back or not -- I think there is some stuff that I'd like to know beforehand:

First, in addition to replacing the 20a breaker, should I also switch the 15a receptacle w/ a 20a? I only have the one receptacle on my circuit...

Second, what's involved in swapping my existing 120v circuit to 240v? The compressor is currently wired for 120v but I do have the option of converting it to 240v if I must. How much work will it take?

And third, how at fault is this electrician? Is this something he should have foreseen? How much of this is his responsibility? I don't like that he passed off old as new. Or that he made excuses when he was found out. But most of all I don't like the idea of giving him more money if he's burning me, deliberately or not.

Any help/info/input will be greatly appreciated...

[Tony Hwang]

me,

Hi, Breakers come in many different specs. That breaker should be surge tolerant type. 1 Hp is ~750W. You do the math.

[Brian V]

1, You paid for new, you should get new. I would make him replace it. 2, Is there a permit involved? What did the inspector say? 3, What gauge wire did he use? Should be 12 for a 20a, newer romex is yellow for 20a, white for 15a. 4, You paid for a 20a circuit, should be a 20a outlet! 5, What amperage does the compressor require at 120v? 2hp should not be that high. 6, Is the cable run excessivley long? If so, might have to up the gauge of the wire.

[Mikepier]

me,

Before you start chasing your tail I would try the compressor in another dedicated circuit to see if the same thing happened ( for example a 20A A/C outlet). If the same thing happens, something is not right with your compressor.

Otherwise try another breaker. An old breaker should work OK, but just to confirm this, if you have another 20A breaker in the panel, try swapping them. Technically it should be on a 20A plug ( although I thought I read somewhere you are allowed to have a 15A plug on a 20A circuit), but regardless, this is not why your breaker is tripping.

It's not hard to convert the circuit to 240v. But if your compressor has a 110V plug on it, I'm assuming you would have to rewire the compressor and get a new power cord with a 240 plug on it. You would also have to do a little rewiring in the panel and get a 2 pole 20A breaker.

[at]

Yep, I intend to!

No permit involved... no inspection.

He used 12ga.....

And that's what I thought too. But what I was wondering was whether this might be impacting my situation.

That information is not in the specs...

It's a very short run... a 2ft drop to a J-box directly beneath the panel. And then 6ft across to the receptacle.

[Stormin Mormon]

Breakers do get weak -- and sometimes weak breakers trip more easily. They aren't all that gosh awful expensive. HD has breakers for common panels for about six bucks each. As another poster said, they do have slow blow breakers (I know; slow blow is a fuse term).

I hope he used 12 gage wire, which is consistent with the 20 amp breaker.

Yes, a 20 amp breaker woulda been good. They are about two or three bucks more.

Your electrician ought also run the compressor for awhile. See what the actual current draw is, and see if there is enough voltage at the compressor end of the wire. While it's running. This is extra time, but would be good customer service.

[at]

The closest designated circuit is outside and it's raining. But I bought a new

20a at Lowe's last night and once I've had my coffee I'm going to try that out.

I've heard the same thing. But I wasn't sure whether that could be contributing to my problem. .

Yep. Apparently Sears Service Center sells a 240v kit for that...

And that sounds like a job for my young electrician...

[Steve Barker]

He should have looked at the compressor and seen how many amps it pulls. (Mine says 24) He should have also noticed it was convertible, and recommended you run it on 240v. It IS possible the breaker is weak, but I'd lean more towards the fact that it just flat pulls more than 20 amps on startup. You'll either need to convert it to 240v OR put in a 30a outlet. And yes, since it is a dedicated circuit, you should be able to run 240 through the 12ga wire he installed. If in fact he used 12ga wire. Just install a double pole breaker, tape the white wire black, and put both wires on the breaker. THEN, tape the white wire black on the other end, put in a

20a 240v outlet, change the plug on your compressor and wire it according to the plate on the motor.

[Steve Barker]

on point #4. A 15a outlet is acceptable if it's a duplex.

[Doug Miller]

After the guy screwed up one install, and cheated you by installing used parts but charging you for new, you'd hire him back for another?

Incredible.

[zxcvbob]

Did you pay him a kid's wage or an electrician's wage?

You have 2 receptacles on the circuit (you said it was a duplex device). There's no need to change it to a 20A if it matches the plug on the compressor cord. If it was a simplex device, it should have a 20A pattern, but that's not the case.

About 5 minutes if it's a convertible motor. Make sure it's running the right direction when you're done. Another 10 minutes to change the receptacle and rewire the breaker.

me,

Check what size wire he used. (why did you hire an electrician anyway?)

Bob

[Edwin Pawlowski]

With a duplex, 15A meet code.

2HP will draw about 13A running, but when a compressor starts, it takes one heck of a lot more. You also have to consider the duty cycle of a compressor. They often have a limit of so many starts per hour.

[at]

I really wasn't thinking about hiring him. I was merely thinking of having him do the work. What I had in mind was more of a restitution type of scenario. It's why I'm fishing for info here BEFORE I confront him again. I know without a doubt he tried to cheat me But I don't know for sure he botched the job. If he did, well then I have a little more leverage w/ which to negotiate.

[Edwin Pawlowski]

Acceptable

Not much, but it may require running 12/3 instead of the present 12/2

As for responsibility, that depends. Did you tell him "I want to run this compressor, please run the proper wiring" or did you tell him what to install? A good electrician will know what is needed, will ask about hte draw of the compressor, etc. He will know that when a compressor cycles, it will draw far more than the rated amps for a second and install a quality breaker to handle it.

As for using a used breaker, he save only a couple of dollars. Was money the motive or did he just happen to have a used breaker and no new one? He should have either told you or just went and got the right breaker. Unless he worked very cheap, you got screwed. The fact that hte breaker is used done not mean it is bad, but it does bring up the integrity of the electrician. We of the use used equipment, but in an industrial setting, it may meant thousands of dollars difference, not five bucks.

[Dave Martindale]

Breakers do fail occasionally. I once had a 15 A circuit that would sometimes trip when loaded with a toaster (~9A). Replaced the breaker with a new 15 A unit and it never tripped again.

Anyway, if he installed a used unit with no warranty, he should have told you that and billed you for the value of the used unit. If he charged for a new one, he should have installed a new one (with warranty). Anything else is dishonest.

Doesn't make any difference if the compressor has a standard 15 A plug.

The advantage of 240 V is that you'll reduce the current and the voltage drop in the wiring by a factor of 2. At double the line voltage, the percentage voltage drop will be 1/4 what it is at 120 V. But with a short run from the panel, there's probably not enough voltage drop to care about.

To do it, you'll need a double-pole breaker, a 240 V outlet, and some tape on the white wire in the Romex. On the compressor, you'll need to rewire the motor connections and change plugs on the cord.

Dave

[mm]

If he's out on his own, he doesn't think he's a kid, so I don't think he deserves slack.

If he works for anyone else, you should tell the boss, who will chew him out better than you can, and who needs to know before his employee kills someone.

Of course he should redo the work at no charge, and you should watch him do it.

I don't know how much needs to be redone except there should be a new breaker. Old and new are not the same thing, the wise ass.

(I would use old if I had one, for myself only, and I wouldn't charge myself the new price.)

[Sonny]

(1)A new 20 amp breaker costs ONLY $3.97, regardless of the Brand... (2) It is common Practice to use an old breaker If the electrician Has one available in thier Truck (3) Granted , Breakers sometimes Do get weak, and if this one is giving You problems, then Yes the Electrician Should replace it with a new one , this is not going to make or break the bank (4) To convert the power source to 240 volt is as simple as pulling the white wire off the neutral bar and installing a new 2 pole 20 amp breaker in the panel, then putting both the black and white wires on to the new breaker (5) Subsequently, you will need a new 240 volt receptacle and plug to the compressor (6) 220 volts will give quite a shock if handled inappropriately, Turn the breaker OFF , Do Not work on it live!!! (7) Finally, WIRING IS NOT A HOBBY, HIRE A QUALIFIED ELECTRICIAN

[at]

Which makes me wonder why an electrician wouldn't have scads of such breakers already on his truck -- especially since they're so cheap and used so often.

I once repaired lawn sprinklers for a living. And from time to time I had cause to use whatever was available -- but only in an *emergency* to get a system up and running -- and never as part of a new installation.

Granted, I realize that wear and tear on electrical parts may not be comparable with plumbing valves and sprinklers. But old and used is still old and used, is it not?

And that's why I did not attempt to do the job myself.

Update: After doing some further research online, it appears the problem may not be with the wiring at all but rather with a pressure relief valve on the air-compressor. Apparently it's a fairly common issue with Craftsman compressors, and further, it's a situation that is NOT improved by switching over to 240v... Or so I've been told. I've got a Sears service call lined up for tomorrow and I'll know more then.

[mm]

Yep.

The fact that it's only 4 dollars might mean that he is only over=charging by 3.50 plus whatever markup he took on the switch, or if he didnt' itemize and quoted a flat price, maybe he didn't "overcharge" at all.

But it also means that it would have only cost the electrician 4 dollars to put in a brand new switch.

People who read my posts here know that I am almost always on the side of repair and reusing, but it is different when one is a contractor. People expect new, and new (of the same quality) is better than old. In fact when one removes an old breaker, it's because it was suspected of being bad, or it was a remodel when it's quality is probably not known at all.

Use it up, fix it up, make it do, or do without. I believe in that most of the time. But new work or parts replacement, not by the homeowner himself but by a contractor, is an exception.

(I might have the saying wrong, but not so far wrong that I can't find it in Google. And yet I can't find it. .... found two hits when I put single quotes around 'fix it up', but not when I just put a + in front of 'it'. I thought the phrase was more common.)

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