What is the intent behind the rule that a jumper be placed from one side of the water meter to the other when the cold water line is used as a ground connection? Is it because the meter could be removed and the ground lost? or due to some issue with conductivity through the meter? or something else? Thanks.
Is the water pipe being used as an electrode or is there 10 feet of metal water pipe in contact with earth?
I think that the ground contact is the main factor. I recommended that an additional grounding conductor be installed and clamped to a metal stake driven into the earth.
Hi Greg the intent is to maintain a continuous grounding path should the meter be required to be removed for servicing.
You answered your own question.
Regardless of there is 10 feet(being used as a gec) or not, if there is metal piping there should be a bonding jumper around removable components (water meter, heater, demineralizer, etc) and it should be properly bonded for a low impedance ground fault path.
Herein lays the confusion between bonding and grounding when it concerns a metal pipe.
There is no requirement to bond around anything and there is no requirement to make a metal pipe electrically continuous when we are bonding the pipe.
The requirement to bond around removable devices if found in 250.53(D)(1) so let’s take a short minute and look at this section of the code.
First this section is found in Part III which is **“III. Grounding Electrode System and Grounding Electrode Conductor” **
Part Three address two different aspects of grounding which comprises the Electrode and the Electrode Conductor.
Second 250.53 addresses the electrode system installation “250.53 Grounding Electrode System Installation.” 250.53 address nothing but that part of the metal pipe that is part of the electrode. In 250.52 we are told that only the first five feet can be used as the electrode. “Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system.”
Third subpart (D) of 250.53 address a metal pipe that is underground “(D) Metal Underground Water Pipe” This subpart addresses the metal pipe that is being used as part of the electrode system and has two subparts one of which a seems to cause a lot of confusion.
Forth is Sub Part (1) found in 250.53(D).
"(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."
This part addresses the continuity of the first five feet that is part of the electrode and covers the requirement found in 250.104 which is the requirement to bond that part of the metal pipe that is on the interior of the building and not part of the electrode system.
Continuity is required to be maintained between the electrode and the interior part of the metal water pipe and this is accomplished through bonding around removable devices.
In This Slide the blue metal water pipe is the underground electrode and the green is the first five feet of the metal pipe that is on the interior of the building and is also part of the electrode. The red is the interior metal pipe and is required to be bonded by 250.104 and this is accomplished with the purple bonding jumper outlined in 250.53(D)(1).
In This Slide there is no metal pipe that is part of the electrode and the interior pipe is metal. Although there are removable devices in the metal pipe the only requirement is to bond the pipe as outlined in 250.104 and there is no requirement to bond around anything.
I was under the impression from previous posts, there was confusion about doing it.
“huh huh he said ‘doing it’ huh…” “yeah yeah, doing it!”
Ok now I’m confused about your post.
Please no reply necessary.
This confusion needs to be cleared up for all involved, don’t you think?