[mhpaavola]

What are the grounding requirements for water meters with metal underground watger pipeing coming into the building?

[tkrussell]

The NEC can be reached by using this Sticky Note found at the beginning of the Electrical Forum:

https://www.askmehelpdesk.com/electr...ne-270277.html

You will find:

250.53 Grounding Electrode System Installation.

(D) Metal Underground Water Pipe.

(1) Continuity. Continuity of the grounding path or the bonding connection to interior piping shall not rely on water meters or filtering devices and similar equipment.

Therefore, a bonding jumper shall be installed to jump out the water meter.

Usually the grounding electrode conductor connected to the water line is left longer to jump out the meter.

[ma0641]

There are no grounding requirements for water meters. Are you talking about grounding the electrical service through water piping?

[mhpaavola]

What gauge does the bonding jumper have to be for the water meter? What is the code number and requirement for grounding the service to the panel? Thank you.

Marty

[tkrussell]

This "jumper" will be considered as a continuation of the grounding electrode conductor, therefore see Table 250.66, and related code sections.

[ma0641]

Table 250-66. Bonding jumper size depends on the size of the service entrance conductor but usually it is a #4

[tkrussell]

Ma0641, #4 copper is the grounding electrode conductor, or main bonding jumper, only for ungrounded conductors at #2/0 to #3/0 copper or #4/0 to #250 MCM aluminum.

The term "usually" will only apply to services using the size service entrance conductors I mentioned, and the term "usually" should not be used so casually.

[ma0641]

Well taken and struck from future vocabulary. Thanks, Brian