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-   -   7.5 HP 80 gallon industrial 2 stage compressor (http://www.houserepairtalk.com/f9/7-5-hp-80-gallon-industrial-2-stage-compressor-3385/)

Scot Clark 01-16-2008 11:04 AM

7.5 HP 80 gallon industrial 2 stage compressor
 
Hi:

Porter-Cable CPLMC7580V2C 7.5 HP 80 gallon industrial 2 stage compressor.

Specs:
Voltage/Hertz/Phase: 240/60/1
Horse Power: 11.00 peak, 7.5 run
30 Amps @ 240 Volts.

Instructions say "minimum branch circuit requirement" : 30 amp.

I'm leaning towrads using a 40 amp breaker, 8-2 wire w/ground.
Does this seem right? I'm concerned if I used a 30 amp breaker
with 10-2 wire it might trip the breaker when it kicks in.
It's only about 35 to 40 feet away from the electric panel.

Now also thinking about this idea: wire it up with a 50A breaker and 6AWG wire and NEMA 6-50 recepticle and put a NEMA 6-50 plug on the compressor. That way I can also use the recepticle for a Lincoln 220 welder
that has a NEMA 6-50 Plug requiring 50 Amp circuit and a Lincoln 180C welder that came with a NEMA 6-50 Plug requiring a 40 AMP circuit.
This would save me from running a line for the welders. I would never
use the compressor or any of the welders at the same time.
Just wondering if using a 50 AMP breaker is too much for the compressor
by not providing enough safety by not being able to trip if or when needed.

Thanks !

kok328 01-16-2008 04:01 PM

All the industrial compressor I've worked with are 3 phase not single. They are also setup to run constantly with load and unload pressure points that keep a steady supply of air in the tank. Your unit should state the FLA and that will determine the amperage required.

guyod 01-16-2008 05:14 PM

Installing a sub panel might be a little more work but would allow you to use both plus what ever toys your get in the future.

speedy petey 01-16-2008 06:35 PM

Quote:

Originally Posted by kok328 (Post 14460)
All the industrial compressor I've worked with are 3 phase not single. They are also setup to run constantly with load and unload pressure points that keep a steady supply of air in the tank. Your unit should state the FLA and that will determine the amperage required.

This is NOT an "industrial" compressor. It is a P-C compressor with the word "Industrial" on it. There IS a difference.

Also, the ones you are referring to a pretty rare, at least around here. In fact I have never even seen one that runs constantly. Pretty wasteful IMO, I don't care how mush it is used.

First off, this is NOT a true 7.5hp motor if it is only a 30A draw. A "real" 7.5hp motor @ 240v single phase should be around a 38-40A draw.
This is probably one of those "developed HP" ratings, like Craftsman shop vacs have. We ALL know, there is no such thing as a 6hp shop vac with a standard 15A plug on it. :p


Scot,
If the actual draw is 30 amps then DO use #8 wire and a 40 amp breaker.

There are MANY odd and special codes regarding motors. Read NEC Art. 430. Your head will spin.

guyod 01-16-2008 07:02 PM

I fell for the developed hp rating on the shop vacss . i cant believe i every fell for that. I remeber thinking " i dont think 3hp is strong enough for what i need better go for the 6hp " lol

Scot Clark 01-17-2008 05:47 AM

Hi Folks: Thanks again for the advise.

triple D 01-29-2008 11:44 PM

good God
 
If you have a name plate rating on a lift or a compressor or a shop vac. or any g.darn thing wire for the name plate rating. 30 amps is 10 ga. wire.... if it says 30 amp min circ size, this doesnt mean you will catch on fire, or that the breaker will need frequent resetting!!!!! Have you seen the price of wire lately fellas??? If a name plate rating is above a division of 10 (examp. 33 amps) round up to next breaker as 30 wont work If plate says max. rating you may need fuseable disconnect to hit something like 35 amp or 45 amp. And hel& no dont run it on 40 or 50 amp this is over fed and unsafe!!!! Put plug for welder closer to panel, it will be cheaper. compressor needs 30 amp 240volt breaker and 10ga wire copper.


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