Sub to sub grounding


  #1  
Old 06-27-07, 10:33 AM
H
Member
Thread Starter
Join Date: Apr 2005
Location: Houston, TX
Posts: 74
Upvotes: 0
Received 0 Upvotes on 0 Posts
Sub to sub grounding

Here is the situation:
The Main Disconnect is on an outside wall next to the meter.
Directly behind it on the inside wall is the primary breaker panel. Since this primary panel (I'll call Sub#1) is technically a sub panel, the ground and neutral are isolated.
Sub#1 feeds another sub (Sub#2) through another wall 20 feet away which serves only the kitchen circuits (many) and the garage (few).
For the ground conductor from sub#2, is it preferable (or required) to bypass the ground bus on sub#1 and run it directly to the disconnect? Or should I tie it to the still isolated ground bus on sub#1.
Or does it even matter? This is still in the design stage and I can do either.
Thanks.
 
  #2  
Old 06-27-07, 10:37 AM
R
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,245
Upvotes: 0
Received 0 Upvotes on 0 Posts
Yes, it matters.

You need a four wire cable from sub 1 to sub 2. The ground from sub 2 must go back to the ground in sub 1.
 
 

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