30 AMP air compressor and NEMA 10-30?


  #1  
Old 07-26-12, 04:19 AM
Q
Member
Thread Starter
Join Date: Jul 2012
Posts: 6
Received 0 Votes on 0 Posts
30 AMP air compressor and NEMA 10-30?

Hi Folks,

Lets assume I have a large air compressor that require a 30amp breaker. Is is okay to wire the motor for use with a NEMA 10-30 receptacle (dryer) which I already have one installed? Or do I really need to use a 6-30?

Thanks!
 
  #2  
Old 07-26-12, 05:53 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,575
Received 15 Votes on 13 Posts
You really need two hots and a ground. The receptacle probably has two hots and a neutral. A neutral really shouldn't be used as a ground. How is the receptacle wired. Does it have a green or bare or is it wired with a white neutral? Is it connected to the panel by continuous conduit so it could be swapped out for a 14-30R? Is it from a subpanel or from the main panel (first OCPD).
 
  #3  
Old 07-26-12, 05:56 AM
Q
Member
Thread Starter
Join Date: Jul 2012
Posts: 6
Received 0 Votes on 0 Posts
It is wired from a 30amp double pole breaker on a subpanel. I'm not sure about the wiring colors - but i'll look.
 
  #4  
Old 07-26-12, 05:59 AM
Q
Member
Thread Starter
Join Date: Jul 2012
Posts: 6
Received 0 Votes on 0 Posts
Should also mention that I have two slots left in the subpanel, so I can add another 30amp breaker and wire whatever is most appropriate. I'm just not sure what is "most appropriate" for a compressor.
 
  #5  
Old 07-26-12, 06:07 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,575
Received 15 Votes on 13 Posts
Grounds should be separated from neutral in a modern subpanel. That is four wires supplying the subpanel. The subpanel will have an isolated neutral and bonded ground. If that is the case with your subpanel I would recommend running a new circuit. You can use 10-2 and remark the white red (or black or any color but white, gray, or green).
 
  #6  
Old 07-26-12, 06:23 AM
Q
Member
Thread Starter
Join Date: Jul 2012
Posts: 6
Received 0 Votes on 0 Posts
Okay, I will run a new circuit. Is NEMA 6-30 the best choice?
thanks!
 
  #7  
Old 07-26-12, 07:18 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,575
Received 15 Votes on 13 Posts
Is NEMA 6-30 the best choice
It or L6-30 is the code compliant choice.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: