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#163022 - 04/29/07 08:41 AM GEC and sprinkler system
leespark Offline

Registered: 01/17/04
Posts: 54
Loc: Massachusetts
How should I handle the grounding electrode system for a 400 amp service?

I plan on installing a 1/0 copper from the main disconnect to the within 5' of where the water service enters the building and jump the water meter unspliced. I am also installing a #6 from the main disconnect to 2 ground rods spaced at least 6' apart.

However, this building has a separate incoming water service for the sprinkler system. Can I install a bonding jumper sized according to 250.66 (1/0) from the sprinkler service to the water service and connect it to the GEC using a split bolt? Or should this conductor also be run back to the main disconnect? I'm a little confused by 250.70 which I beleive is referring to my situation.


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#163024 - 04/29/07 08:53 AM Re: GEC and sprinkler system [Re: leespark]
Alan Nadon Offline

Registered: 03/10/05
Posts: 398
Loc: Elkhart, IN. USA
There are different ways of doing this and complying with the Code.
1. From the sprinkler system (within 5 foot of entry*) take the wire to the service.
2. From the sprinkler (within...*) take the wire to the GEC and use an irreversable crimp, not a split bolt.
3. From the sprinkler take the wire to the water pipe and use a pipe clamp.
4. If you have building steel go from the service to the steel. Then you can take the water to the steel and the sprinkler to the steel.
The last method saves alot of copper.
If it was easy, anyone could do it.


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