Connections to Cold Water Pipe

Grouch

Grouch

Senior Member
Location
New York, NY
In an existing building in NYC, 2 of the Service Switches are grounded via individual GEC's to the cold water pipe; each switch has its own GEC going to the cold water pipe, terminating with its own clamp on the water pipe. So there are 2 clamps on the water pipe.

One of the clamps has an additional GEC that then runs to a ground rod.

My question is: Can this connection to the ground rod, originating from only one of the water pipe clamps, also apply to the other clamp? In other words, does the ground rod connection apply to both of these service switches?

I would assume the answer is yes.
 
If you take a look at 250.68(C) cold water can be used as a way of bonding multiple electrodes. It can be considered a grounding electrode conductor.

Another example of one is building steel. Building steel, while not always considered an electrode itself can be used as a grounding electrode conductor to bond multiple electrodes.
 
Just to make sure my question made sense, I made a crude sketch on autocad, attached here.

2 Service Switches, each grounded to the cold water pipe with its own clamp. And then the clamp that connects to Service Switch #2 also connects to a ground rod. Does this connection to the ground rod also apply to Service Switch #1?

In response to post #2, yes, both clamps are within the 1st 5 feet of the pipe's entrance.
 

Attachments

  • Grounding Sketch.pdf
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The only point I would add is that running the GEC for service switch 2 through the pressure connection would mean you would size that conductor to table 250.66. If you landed a 3rd pressure connector you could size the conductor from the rod to the cold water pipe with the minimum size for a rod. Which would be #6 copper.
 
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