Tractor Supply Job Smart won't start unless pressure drained

by Mike
(Memphis, Tn)

This is a 1.5 hp, direct drive, 125 psi, 26 gal upright. Just bought this used and does ok until it's used to the point of turning on again. It won't run, just hums.

If I drain the air to 40-50 psi it'll run slow then slowly increases rpm's until it's up to speed.

I metered the capacitor and it's good. The seller said it didn't have many hours use and I believe him. It's 1.2 years old and very clean with no dust anywhere, not even in the nooks/crannnies.

The seller ran it before I bought it. It was @ 125 psi therefore wouldn't start so he he drained it to 80 psi and it started no problem. Now it won't, unless it's drained to a lot lower pressure.

I hauled it home upright but can't figure out what went bad between there and here. Maybe as a fluke the unloader went bad? How would u check that?
_____________________
Mike, check the operation of your unloader valve. See Unloader Valves on the site map for more info on them, if you need it. Make sure it is working each time the compressor reaches cut out pressure.

Also, make sure you are not using an extension cord.

Any change?

Cheers,

Bill




Comments for
Tractor Supply Job Smart won't start unless pressure drained

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Feb 20, 2012
 Reply
by: Mike

Bill, I did make a misleading statement due to distractions as I replied. Our dog barking, wife and daughter talking, tv, blaa blaa blaa. Anyway, I stated I felt no resistance when turning the motor/compressor by hand. I meant to say there's no resistance beyond what you would normally feel. As for the motor, yep, I was afraid you'd say that because I've thought the same. Cost? I don't know if it's worth the repair or not because it didn't come with a manual and can't find one online. I searched Tractor Supply's site with no luck then contacted them but so far, no reply. Lastly, although I didn't get it going your suggestions/time were appreciated just the same.
Feb 18, 2012
 Unloader
by: Mike

Hi Bill. I drained the tank empty then tried running it again. Yesterday I could drain it to 50 psi +/- and it would start/run/shut off @ 125 psi. This time (today, empty) it spun MAYBE 1 second then stopped/hummed. While the tank was drained I took the unloader off and it's clean, moves freely and looks new. Doesn't necessarily mean it's good but since it wouldn't run, that's all I can say. I turned the motor's fan and felt no resistance/binding. I tried running it twice and each time tried discharging the capacitor with a screwdriver. There was NO arc either time. The capacitor isn't bulged anywhere, nor does the motor smell burnt. It is plugged into a wall receptacle so no extension cord is used. The capacitor is black so I assume it's a starting capacitor?
Thx, Mike
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Assuming that the power supply is good, the capacitor is good, no mechanical issues with the pump, then I suspect your "almost new" compressor has a motor problem, Mike. My next step would be a load test on the motor. But, how much do you have into it, and how much more do you spend on attempting to repair a low cost compressor? That one is up to you. It could look brand new, but have been run way past its duty cycle and fried the motor.

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