Grounding electrode proximity to Service disconnect

N

nizak

Senior Member
I have a scenario ( residential) where the incoming copper water supply is almost 225’ per wire route from the service disconnect.

Is there a point when the distance of the wire run outweighs the effectiveness of dissipating the fault?

The entire length of the wire run is in the building interior . I t consists of traveling through wall space, attic space, crawl space and above a portion of dropped ceiling.

It is literally the furthest point from A to B.

There are currently 2 8’ driven rods at the service but the copper water is available just in no way convenient.

Does it need to be used if I can prove 25 ohms or less at the 2 driven rods?
 
I personally would argue to any inspector that the water line is not a usable/feasible grounding electrode being that far.
 
nizak said:
I have a scenario ( residential) where the incoming copper water supply is almost 225’ per wire route from the service disconnect.

Is there a point when the distance of the wire run outweighs the effectiveness of dissipating the fault?
Click to expand...
What does it mean to 'dissipate' a 'fault', and what does that have to do with the grounding electrode?

nizak said:
The entire length of the wire run is in the building interior . I t consists of traveling through wall space, attic space, crawl space and above a portion of dropped ceiling.

It is literally the furthest point from A to B.

There are currently 2 8’ driven rods at the service but the copper water is available just in no way convenient.
Click to expand...

Is it confirmed that the water pipe is actually an electrode? Can you bond the water pipe closer at a point where it is electrically continuous to the pipe in the ground?

See the discussion started here and picked up here. You can try this argument with the inspector, that the code doesn't actually say the water has to be bonded where it enters the building.

Or you can do Tom's idea.

nizak said:
Does it need to be used if I can prove 25 ohms or less at the 2 driven rods?
Click to expand...
No, this makes no difference to the code requirements.
 
I guess one option to avoid this would be to splice in a short piece of non metallic pipe in the water supply line. And then there would be no water pipe electrode available. Next case...
 
texie said:
I guess one option to avoid this would be to splice in a short piece of non metallic pipe in the water supply line. And then there would be no water pipe electrode available. Next case...
Click to expand...
I like it.
 
You must log in or register to reply here.
Top