Grounding

Hi, student inspector, getting ready to take the exam next month. Been practicing whenever possible. Just curious about the picture since I have not seen this before. Is this common practice to use the bathroom sink? The panel is right outside this half bath. Other issues like broken and corroded valves and an active leak.

Thanks in advance

I would not say this was common but can be found in older homes.

Grounding to plumbing pipes is not considered safe anymore because a section of the plumbing system may have been replaced or can be replaced with PEX which does not conduct electricity. I would recommend this be evaluated by a licensed electrician for correction.

Thanks a lot. Very helpful

you’re welcome

great answer

No, this is not acceptable, or common practice anywhere I’ve ever inspected.
The main water supply pipe is acceptable in some jurisdictions as a grounding electrode but the connection needs to be made near where the pipe penetrates the foundation and on the supply side of the meter.

You need to be asking your local building department instead of asking on the message boards. What’s acceptable varies by area.

why specifically on the supply side of the meter?

Doesn’t happen here in Maryland. My water meter is under the sidewalk 50 feet past the house. All these houses were originally grounded through the plumbing (copper entry pipe).

When the meter is in the house a copper jumper wire (6 awg) jumps past the water meter to insure continuous continuity.

Plumbing grounds only work if the water entry pipe is metal of course. Not done anymore.

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According to the NEC the connection is required within 5’ of the entry of the water pipe into the structure and it can be on either side of the water meter. As Robert stated the water meter requires a bonding jumper regardless of which side of the meter that the GEC is connected to the pipe.

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I have seen plenty of water pipe used as a grounding electrode, I have never seen a jumper at the meter or it was just not visible for some reason. Do you think that jumper has been required for decades or recent requirement?

Older code cycles (I’m using 1965 as an example, see below) required a bonding jumper across the meter when the GEC did not land on the street side of the water pipe. The 5’ maximum rule was added in the 1996 NEC (see below). The 1978 NEC added the wording regarding the meter bonding jumpers.

1978 NEC:
250-81(A) Continuity of the grounding path or the bonding connection to interior piping shall not rely on water meters.

1965 NEC:
250-112. To Electrode. The grounding connection to the electrode shall be located as follows:
(a) To Water Pipes. System or common grounding conductors shall be attached to a water piping system on the street side of the water meter or on a cold water pipe as near as practicable to the water service entrance to the building. Where the source of the water supply is from a driven well in the basement of the premises, the connection shall be made as near as practicable to the well. Where practicable, the point of attachment shall be accessible. Where the point of attachment is not on the street side of the water meter, the water piping system shall be made electrically continuous by bonding together all parts between the attachment and the street side of the water meter or the pipe entrance which contain insulating sections or are liable to become disconnected, as at meters, valves and service unions.

1996 NEC:
250-81 Interior metal water piping located more than 5 ft (1.52 m) from the point of entrance to the building shall not be used as part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system.

wow, nice. Thanks!

You’re welcome Brian. Sorry about the look of the 1965 code section it reformatted when I pasted it into the post.

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