Ground rods

[illicit affairs]

I'm working on a service panel upgrade for a client's home and they want me to tie into the water line for grounding. I'm a bit unsure if I need one or two ground rods with that setup. What does the code expect for 200 amp panels these days? Would hate to get called back HAHAHA.

 

[CircuitRick]

For a 200 amp service, the NEC requires a grounding electrode system. If you use the water line, you must supplement it with at least one additional electrode, typically a ground rod. For safety reasons and to avoid resistance testing, it's common practice to install two ground rods, spaced 6 feet apart. Your local AHJ might have specific requirements, so always double-check!

 

[PGB1]

Typical in this area for any service under 250 volts to ground is to install the two grounding electrodes, as mentioned by CircuitRick. They don't necessarily have to be rods. They can any of the other allowed items in 250.52 of NFPA 70.

But the metal water piping system is always well grounded. At the entrance to the building, it is attached as though part of the grounding electrode system.

Instead of considering it as a part of the grounding electrode system, the connection's function is to bond the water piping system in order to maintain the same equipotential as the system ground. This can be a challenge because of the intermittent use of non-metallic pipe, tubing or fittings in the water system.

Depending on the likelihood of the gas line piping becoming energized, we often bond that as well.