Welcome to the The Garage Journal Board forums.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   The Garage Journal Board > The Garage > Lighting & Electrical

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-03-2010, 10:49 AM   #1
Thunderpigeon
Junior Member
 
Join Date: Sep 2007
Location: Milwaukee, WI
Posts: 22
Default Circuit Breaker And Wire Size For 5HP Air Compressor

I am in the process of hooking up my air compressor. The compressor has a 5 horsepower motor and will be located 45 feet away from the main electrical panel box. What size circuit breaker should I use, and what gauge wire should I use?
Thunderpigeon is offline   Reply With Quote
Old 09-03-2010, 11:02 AM   #2
phiftyseven
Member
 
Join Date: Sep 2007
Posts: 54
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

Will need more info before that can be answered. Single phase or Three phase ? What voltage will you be using ? What's the amp draw on the motor nameplate ?
phiftyseven is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 09-03-2010, 11:06 AM   #3
Thunderpigeon
Junior Member
 
Join Date: Sep 2007
Location: Milwaukee, WI
Posts: 22
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

It is a single phase, 230 volt motor. The plate on the motor indicates 23 FLA and 25 SLA.
Thunderpigeon is offline   Reply With Quote
Old 09-03-2010, 12:20 PM   #4
sberry
Senior Member
 
sberry's Avatar
 
Join Date: Jun 2005
Location: Brethren, Michigan
Posts: 9,777
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

These type of comps run fine from a 10 wire and 30 breaker.
__________________
www.urkafarms.com
sberry is offline   Reply With Quote
Old 09-03-2010, 01:09 PM   #5
Thunderpigeon
Junior Member
 
Join Date: Sep 2007
Location: Milwaukee, WI
Posts: 22
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

Is 30 amps and 10 gauge a rule of thumb or is it based on a calculation?
Thunderpigeon is offline   Reply With Quote
Old 09-03-2010, 01:44 PM   #6
JBurgess
Senior Member
 
Join Date: Mar 2008
Location: Arizona
Posts: 372
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

Here's a calculator for motor branch Circuits.

http://www.electrician2.com/calculat...tor_ver_1.html
JBurgess is offline   Reply With Quote
Old 09-03-2010, 03:44 PM   #7
sberry
Senior Member
 
sberry's Avatar
 
Join Date: Jun 2005
Location: Brethren, Michigan
Posts: 9,777
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

JB is correct to use the calculator and my take was a general rule due to the fact that although it is listed as 5 hp it is closer to 4 real hp. The calc says 8 and one reason I suspect is the allowance for heavy breakers. I am sure it has happened but I haven't seen one of that class trip a 30 and doubt it would ever a 40. The calc is for cable, a wire in pipe would change things a bit also.
A ? for JB and others, I see new breakers are listed with 60/75, this would change the calc also to allow 10? Apparently romex must be used with 60 degree termination?
__________________
www.urkafarms.com

Last edited by sberry; 09-03-2010 at 03:54 PM.
sberry is offline   Reply With Quote
Old 09-03-2010, 06:43 PM   #8
Aceman
Senior Member
 
Join Date: Jan 2007
Location: Eastern Oregon
Posts: 1,819
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

Code says #8 Romex minimum on a 35-70 amp breaker.

I'd use #8 on a 40 amp breaker personally.
Aceman is offline   Reply With Quote
Old 09-03-2010, 07:21 PM   #9
type11966
Junior Member
 
Join Date: Aug 2010
Posts: 23
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

I have a 5hp 24 amp draw. I used a 30amp breaker and 10-2 with ground romex. My licensed electrician friend help me.
type11966 is offline   Reply With Quote
Old 09-03-2010, 07:28 PM   #10
type11966
Junior Member
 
Join Date: Aug 2010
Posts: 23
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

Here is my compressor and the small one in front of it that it replaced.
Attached Images
File Type: jpg 20100816_IMG_2362.jpg (136.0 KB, 100 views)
type11966 is offline   Reply With Quote
Old 09-03-2010, 07:49 PM   #11
sberry
Senior Member
 
sberry's Avatar
 
Join Date: Jun 2005
Location: Brethren, Michigan
Posts: 9,777
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

You have an owners manual for that? Just curious if the wire sizes are listed in installation instructions?
__________________
www.urkafarms.com
sberry is offline   Reply With Quote
Old 09-03-2010, 08:03 PM   #12
Thunderpigeon
Junior Member
 
Join Date: Sep 2007
Location: Milwaukee, WI
Posts: 22
Default Re: Circuit Breaker And Wire Size For 5HP Air Compressor

Thank you for the responses.

I don't have the manual. It is an older Atlas Copco Automan direct drive compressor.
Thunderpigeon is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 09:10 PM.