Air Compressor Help - Tripping Breaker, Bad Smell

[SSINNOVATIONS]

In a bind here and would really appreciate some guidance. I have an IR T30 80 gallon compressor with a WEG 184t frame 5HP single phase motor. I have been doing some light sandblasting with a 110lb pressure pot and the everything was going great but then it died. Its wired to a 30 amp cut/off fused breaker in the garage and a 30 amp breaker at the box in my basement (10-2 romex).

The breaker in the basement tripped, it was late so I left it. Tonight I re-set and fired it up, it immediately tripped the breaker in the basement again and there is an odd smell. No smoke, no sparks.

I'm not sure how to diagnose this problem and and advice would be greatly appreciated!

 

[PT Doc]

Do you have an extra 30a breaker you could swap in to test it?

 

[SSINNOVATIONS]

I don't but could easily grab one. Would a bad breaker cause a smell? The smell from the motor has me spooked....

 

[JASTECH]

I would not replace the breaker until the motor has been checked out fully. You say odd smell? Let's narrow it down. Did you eat beans by chance? j/k
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If the motor smells then you might have burnt the windings. Stop, don't make it worse. Others will chime in.

 

[JASTECH]

Oops, new browser beta testing

 

[SSINNOVATIONS]

I agree, no power to this thing until I figure it out. I pulled the shroud and loosened the belt, motor spins free and easy. Compressor wheel does not turn as easily as I remembered (especially when in a compression stroke), i use to be able to spin by hand over and over, now getting resistance.

There is a copper tube that goes to the head of one of the cylinders and connects to the pressure switch, can these go bad? It's a brand new switch from grainger...

 

[SSINNOVATIONS]

Never mind, forgot there was about 30 psi in the system. Compressor wheel spins pretty freely (probably same as before) and is moving air.

 

[JASTECH]

I wonder how the motor will do w/o a load, do you have a clamp on amp meter?

 

[PT Doc]

I don't but could easily grab one. Would a bad breaker cause a smell? The smell from the motor has me spooked....

You originally sated the breaker tripped and there was a bad smell. I assumed from the breaker. If from motor then you have a bigger problem.

Pull the moor and tie to s motor repair shop for a good once over.

 

[LSU]

My guess/suggestion:

Unplug the motor.

Take the load off the motor by removing the drive belt. Spin the shaft on the motor. If the motor has a spot to add lube oil add some good quality oil. See how the motor feels. Is it smooth? Listen to it when you turn it - hear anything that sounds out of what.

Check your drive belt. Is it cracked, worn, etc.

Examine the compressor. Look at the bearings on the compressor and try turning the compressor without a load.

Now - this becomes a two person job. Get someone to stand by the breaker. If you can holler at them, tell them to turn the breaker on.

Plug in motor (turn it on if there is a switch) and see if motor runs freely w/o a load.

Does the motor trip the circuit when you power up the motor? If so, you're headed to an electrical motor shop or to buy a new motor.

In the off chance the motor is grounding out, I'd be wearing rubber sole shoes and not be grounded "just in case".

If the motor is running freely w/o load, look to compressor for problem.

My guess is the bushings in the motor are fried or a bearing in the motor is fried.

Depending on the make/model/brand of motor you might be able to replace motor cheaper than if you had it rewired. Good electrical motor shops are getting fewer and fewer but (the last 3 I've dealt with have closed) so look around till you find one.

 

[SSINNOVATIONS]

Motor spins freely, slight brushing noise.

I have a breaker in the garage next to the unit so I bumped the power with the belt off the motor, it spins but seems to hum louder than before, and the smell comes back. I fear this is not going to be a cheap fix..... What exactly goes wrong in these motors?

 

[Dick in Wisconsin]

Motor What exactly goes wrong in these motors?

Bad stuff. The kind you and I usually can't fix.

Good electric motor shop or a new motor.

 

[JASTECH]

The bump might be the rotor hitting do to one of your bearings being shot allowing the rotor to move just enough.

 

[GeneralDisorder]

Have you tried starting it without any pressure in the tank? You may simply have a bad tank check valve or your form-x pressure switch isn't bleeding off the pressure. Compressors don't start against a load.

Certainly could be a bad motor though.

GD

 

[RCStocker]

You said 10-2 I think you have 10-3 with a ground. 220 takes 2 110 lines plus the gournd and an equipment ground.

It if is tripping you are drawing to many amps. In which case I would think you have a short in your moter. A short is when the wires are a making contact that should not make contact. A short is not a broken wire.

If you have a meter and know how to check the moter do so. My guess is that you don't now how to check the morter or you would have done so by now. Not problem with that. Most people have no clue.

Remove the moter and take it to a reapir shop for motors or someone who can test it.
I think the problem in the moter.

The only other thing it could be is the length of the rund form your garage to your basment breaker. If it is a long run you will have a voltage drop which will cause the line to over heat. There are wire size charst listed all over the web. Look one up and then measure the length of your run from one box to the next. If you are over 30 feet my bet is that you need larger feed into your basment box. A number 10 wire is not needed to run 220. but a larger number wire is required for longer runs.

220 takes half the amps to run than 110 does. If you are blowing a 30 am breaker you really have problems. that is a larger breaker than you need.

How long have you had this compressor installed? Was it working properly in a different location? Is it new to your basement? If it worked before and new to the basment I would say you don't have the proper wire size Your should have a larger wire size for a 30 amp breaker on a longer run. I am thinking this thing backwards.

Check the amps on your moter and then match the breaker to the required load

Check the wire size for the length of your run. If this is a new instulation my bet is that you need a larger wire in the run.

You can disconnect the power form the motor and check all the leads to see if there is continuity beween any of the leads That would show the short if you do it right.

Take the moter to the garage and hook it up there and run it. If it does not blow the fuse in the garage then you know the moter is fine and that the wire size to your basment breaker need to be propperly sized and a new run installes.

It is really is a no brainer. The charts are easy to read. They are everywhere on the net.
The only problem is that the price of the wire will cause you to take a second job. LOL I would run individual wire in conduit. You can not use romex in conduet. It is has not been tested for heat and does not meet code.

 

[pop pop]

Sounds like electricity is leaking in your motor. It will smell when it first starts leaking. If too much leaks out, it will eventually let the smoke out. Once the smoke is out you'll have to replace it.

Seriously, sounds like you've burned a winding coil and it's shorted.

 

[SSINNOVATIONS]

Have you tried starting it without any pressure in the tank? You may simply have a bad tank check valve or your form-x pressure switch isn't bleeding off the pressure. Compressors don't start against a load.

Pressure switch is only six months old, could still be broken though, when I tried to start it there was about 30 psi in the system.

You said 10-2 I think you have 10-3 with a ground. 220 takes 2 110 lines plus the gournd and an equipment ground.

Correct 10-3, typo.

If you have a meter and know how to check the motor do so. My guess is that you don't now how to check the motor or you would have done so by now. Not problem with that. Most people have no clue

Yeah, I have no clue.. learning as I go on this stuff.

Distance from my basement breaker to the fused switch in the garage is about 50 feet. Compressor has been up and running for several months with no problems.

Full Load Motor amps listed as 28, which is why I went with a 30 amp breaker, I consulted an electrician on the wire size, he said the 10 was minimum so I went with it, and like you said bigger = $$$$

Since it was working fine and now isn't I have to think a component broke. Dropped the motor off at a shop this afternoon, I will know for sure Monday. BTW, holy **** that thing is heavy!

 

[dtaylor]

My compressor did the exact same thing as yours about 4-5 years ago. I replaced the capacitor (which was a start-run capacitor) and it hasn't given any problem since. I would check that before tearing into anything. They are very easy to replace.

 

[SSINNOVATIONS]

Do you remember how much those cost to replace? Also, did it smell?

 

[PT Doc]

28 fla on a 30a circuit? I know that if you talked to the manufacturer, they would recommend a large breaker. Just for a comparison, Quincy specs a 50a circuit for a 5hp 23a Baldor motor.

 

[SSINNOVATIONS]

Pick up my motor tomorrow, bad capacitor. Shop hit me 50 bucks, I bet it's a 10 dollar part but just happy it's nothing more serious.

 

[pop pop]

Money well spent if you don't know, ya know?

 

[bsaint]

Have you tried starting it without any pressure in the tank? You may simply have a bad tank check valve or your form-x pressure switch isn't bleeding off the pressure. Compressors don't start against a load.

Certainly could be a bad motor though.

GD

Jesus Christ - the only sensible answer so far on this page. First thing to check is if your tank check valve is working. Fill 'r up and after its off, crack the unloading tube and see if there is air ******* out.

High starting current can blow your new capacitor.

 

[dirtydogintex]

28 fla on a 30a circuit? I know that if you talked to the manufacturer, they would recommend a large breaker. Just for a comparison, Quincy specs a 50a circuit for a 5hp 23a Baldor motor.

Roughly speaking

FLA + 25% FLA = starting amps
23A + 6A = 29A

Even after taking into consideration R/L 'gotchas' (primarily low line voltage and field wiring voltage drops) it appears Quincy is being extremely conservative.

~~~~~~~

In SSINNOVATIONS' case of 28FLA

28A + 7A = 35A
so time delay fuse/circuit breaker = 40A
8 AWG wire allows 136' @ 220v, 3% drop

Might keep an eye on motor temp/line voltage @ motor esp if blasting or other requiring long/fairly constant run time....