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Discussion Starter · #1 ·
Hello all.
Just today I helped install a new ingersoll rand 15hp 3phase air compressor
Model up6-15ctas-150
We ran #6 on a 60a breaker. When we went to turn it on for the first time, it tried to start and then tripped the breaker???
We didn't hook up the optional 120v dryer circuit, could this be why.?
I'm at a loss, I've never done one of these.
What the heck am I missing here?!
Any help from all you would be greatly appreciated!!

Thanks
Ryan
 

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Assuming there is no electrical fault in the motor ?

The start up surge of a large motor,
with a load on it such as a compressor will be substancial,
whilst your breaker may handle normal running current,
it cannot handle the start up surge.
You need a different type of breaker for motors.
They have a different trip curve.
A slow blow action if you like.
 

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Discussion Starter · #5 ·
I would hope it's no fault in the motor, it just got delivered today! New!
A different type breaker? I've seen someone say online they used a 100a! Made no sense!

What type would you recommend? It is a square D QO bolt-on style panel bus...
Also, we put in a 60a disconnect before the compressor with 600v 60a fuses...
 

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Old Grumpy Bastard
GOV/MIL contracting
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What is the voltage of the unit, you left off the last numbers in the model# that indicate voltage. Did you check amp draw on start with a meter? Starting amp draw on that would be higher than 60amps at 208v.
 
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Sparks fly from my finger
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I would hope it's no fault in the motor, it just got delivered today! New!
A different type breaker? I've seen someone say online they used a 100a! Made no sense!

What type would you recommend? It is a square D QO bolt-on style panel bus...
Also, we put in a 60a disconnect before the compressor with 600v 60a fuses...
You need to read article 430 very much badly. You wasted money on the wrong disconnect.
 

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Discussion Starter · #9 ·
200/3/60
No, I didn't check while trying to start it, I only tried the one time. Took a step back... It a very expensive unit.. Something is obviously wrong, searching for the clues to solve the problem. I appreciate the help.
 

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Old Grumpy Bastard
GOV/MIL contracting
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I would hope it's no fault in the motor, it just got delivered today! New!
A different type breaker? I've seen someone say online they used a 100a! Made no sense!

What type would you recommend? It is a square D QO bolt-on style panel bus...
Also, we put in a 60a disconnect before the compressor with 600v 60a fuses...
A 100amp breaker makes perfect sense and so does 60amp time delay fuses.
 

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Sparks fly from my finger
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According to that, I would need a 300a non time delay fuse?! On a #6thhn?
So? You can put a 200 amp instant trip breaker on a #12. What is your point?

There are a lot of things we are assuming because you have not given much information. Read article 430.

Assuming this air compressor is across the line start you size the wire at 100% fla if it doesn't run for more than 3 hours. The fla is 48.2 amps at 200 volt. That means your inverse time breaker is sized at 250% of fla so that is 125amps. You fuses are more than likely time delay so you size those at 175% of fla so that is 90 amp fuses.
 

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Old Grumpy Bastard
GOV/MIL contracting
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While you were technically correct the code allows more....:jester::jester:
I kind of feel funny giving any advise to a poster that appears to be so limited in knowledge as this kid. Seeing he joined so long ago I almost want to bet it's an alter ego.
 
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Old Grumpy Bastard
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You don't need a disconnect with 600volt fuses. You don't even need a fused dissconect.
Out this way, they always spec fused discos for compressors on any jobs I've been on.
 
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