Whole house surge protection and sub panel


  #1  
Old 08-03-14, 12:39 PM
Z
Member
Thread Starter
Join Date: Feb 2010
Posts: 27
Upvotes: 0
Received 0 Upvotes on 0 Posts
Whole house surge protection and sub panel

If I have a whole house surge protection device wired into one of my main panels, and I attach a sub panel to that same panel, I am assuming I don't need another surge protection device for the sub panel?
 
  #2  
Old 08-03-14, 12:59 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 13,980
Received 196 Upvotes on 172 Posts
The protection would extend to any downstream panels.
 
  #3  
Old 08-03-14, 06:22 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 9,874
Received 185 Upvotes on 166 Posts
You wouldn't need the second surge device, but installing one would be supplemental protection just like continuing to use a surge protector strip at your computer and other electronics locations.
 
  #4  
Old 08-06-14, 05:17 AM
W
Banned. Rule And/Or Policy Violation
Join Date: Jul 2009
Location: usa
Posts: 87
Upvotes: 0
Received 0 Upvotes on 0 Posts
Appreciate what a protector does. It does not stop, block, or absorb destructive surges. Protectors that do that are for surges that cause no damage. Your concern is a surge, maybe hundreds of thousands of joules, that hunts for earth ground destructively via appliances.

Either connect that surge to earth BEFORE it enters a building (ie at the mains box). Or a protector is doing little useful. IOW what is the most important component in every protection system? An item that absorbs hundreds of thousands of joules.

A 'whole house' protector is not protection. It is a connecting device. To be effective, it must connect low impedance (ie 'less than 10 feet') to single point earth ground. A sub panel does not have that earth ground connection. Only the main panel has that. A protector without an earth ground does what with hundreds of thousands of joules?

How to increase protection? Not with more protectors. Protection is defined by earth ground. How to make a protector more effective? Upgrade, expand, or install the single point earth ground. Earthing and how it connects defines your protection; where joules dissipate.

Protectors are simple dumb science. 'Art' of protection is earth ground. That is where most of your attention and questions should focus. Then appliances and power strip protectors have sufficient protection.
 
 

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