Sub Same Building: Date for 4-wires?


  #1  
Old 03-23-17, 05:51 PM
ray2047's Avatar
Member
Thread Starter
Join Date: Mar 2006
Location: USA
Posts: 33,581
Received 13 Votes on 11 Posts
Sub Same Building: Date for 4-wires?

Has four wires and an isolated neutral bar plus bonded ground bar always been required for subs off the main panel when sub is in the same building?

(I know the rules on detached structures originally didn't require 4-wire unless there was an additional path to ground so just wondering about same building rules.)
 
  #2  
Old 03-23-17, 06:37 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 14,126
Received 348 Votes on 301 Posts
Has four wires and an isolated neutral bar plus bonded ground bar always been required for subs off the main panel when sub is in the same building?
Yes, sort of. A ground bar is not required, but there has always been the requirement for a grounding path in the installation. It does not need to be a wire, it can also be steel conduit with approved fittings and installation. (IE: EMT) A ground bar can be added later, if needed.
 
  #3  
Old 03-23-17, 06:54 PM
ray2047's Avatar
Member
Thread Starter
Join Date: Mar 2006
Location: USA
Posts: 33,581
Received 13 Votes on 11 Posts
Tolyn Replied:
Yes, sort of. A ground bar is not required, but there has always been the requirement for a grounding path in the installation.
But in http://www.doityourself.com/forum/el...ug-needed.html Post #34 Taz 420 wrote:
1. You have not been allowed to combine neutrals and grounds after the SE since 1923
I am doubting the 1923 date but maybe I'm wrong.
 

Last edited by ray2047; 03-23-17 at 07:20 PM.
 

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