Thread: Sizing bonding jumper at water meter

1. Sizing bonding jumper at water meter

Is there a straight forward rule for sizing the bonding jumper at a water meter - all I can find is per table" 250.66"... which I cannot seem to find online.

- Thanks

2. Re: Sizing bonding jumper at water meter

At least a #6 copper.

3. Re: Sizing bonding jumper at water meter

Is this what you wanted?

4. Re: Sizing bonding jumper at water meter

Originally Posted by Michael Thomas
Is there a straight forward rule for sizing the bonding jumper at a water meter - all I can find is per table" 250.66"... which I cannot seem to find online.

- Thanks
NFPA 70: National Electrical CodeŽ

This is a link to the 2008 NEC on the NFPA website.
It is a Read Only PDF. You will need to register in order to see it.
But it's better then nothing at all

Scroll down to where it says " view the document online"

5. Re: Sizing bonding jumper at water meter

Thanks to all - I was trying to imagine a "logical" reason why this was attempted on a system with AWG 3 copper service entrance conductors:

6. Re: Sizing bonding jumper at water meter

Originally Posted by Michael Thomas
Thanks to all - I was trying to imagine a "logical" reason why this was attempted on a system with AWG 3 copper service entrance conductors:
MT: Because 2 X 3AWG = 6AWG???

7. Re: Sizing bonding jumper at water meter

Originally Posted by Michael Thomas
Thanks to all - I was trying to imagine a "logical" reason why this was attempted on a system with AWG 3 copper service entrance conductors:
Because it is a legal install.

Table 250.66 states that #2 or smaller copper you use a # 8 copper for the jumper.

#3 copper is smaller then #2 copper.

Wire sizes up to #1 ---> The SMALLER the number the LARGER the wire.
(Just like #14 is smaller then #12)

It is this way until you get to 1/0. Then you go 1/0,2/0,3/0,4/0, 250,300,350,400,500 ......

8. Re: Sizing bonding jumper at water meter

The size is correct however the installation is incorrect. The second, unnecessary wire, appears to be between the ground connector and pipe. As you can see by the corrosion it will reduce the effectiveness of the correct ground wire.

9. Re: Sizing bonding jumper at water meter

Originally Posted by Ken Rowe
The second, unnecessary wire, appears to be between the ground connector and pipe.

I don't know that the second wire is unnecessary ... but I expected Ken H. to have mentioned that it was improperly installed instead of "Because it is a legal install."

That is a pipe grounding clamp with a terminal for the grounding conductor, the clamp clamps onto the pipe, then the conductor goes into the terminal.

As you can see by the corrosion it will reduce the effectiveness of the correct ground wire.
The corrosion looks like it is because of dissimilar metals: the clamp is dissimilar from the pipe - notice the brass/bronze clamp just above it on the copper pipe with no corrosion, versus this clamp being steel and having corrosion.

10. Re: Sizing bonding jumper at water meter

Sorry the picture was unclear, those jumpers are 8 AWG, so why is the second (unnecessary and incorrectly installed) jumper there?

(Other than "All two-six-pack installations shall be provided with two jumpers, as specified in table 350.266, if you see double when you look in the book..." ).

I know given the the way its cobbled up its probably just a failure of the Bozone Layer. But when I see something like that, I just cannot stop myself from asking "is there a possible why?"

Last edited by Michael Thomas; 02-28-2010 at 02:09 PM.

11. Re: Sizing bonding jumper at water meter

Originally Posted by Jerry Peck
I don't know that the second wire is unnecessary ... but I expected Ken H. to have mentioned that it was improperly installed instead of "Because it is a legal install."

That is a pipe grounding clamp with a terminal for the grounding conductor, the clamp clamps onto the pipe, then the conductor goes into the terminal.
I was replying to the Original post and the original question, inquiring about SIZING the bonding jumper. Leaving the picking apart of the install to those of you who do so enjoy such things and lo-and-behold I was not disappointed

12. Re: Sizing bonding jumper at water meter

Originally Posted by ken horak
I was replying to the Original post and the original question, inquiring about SIZING the bonding jumper. Leaving the picking apart of the install to those of you who do so enjoy such things and lo-and-behold I was not disappointed
I was waiting for other replies to assess what was asked and and what was shown, and I know how you used to (not as much now) try to pick responses apart, (others did to, and are also much better at controlling themselves too ), so I expected your post to be spot on as you seem to enjoy doing such things and lo-and-behold I was ... disappointed.

Sorry, could not resist either.

Usually, the question is answered and then we continue to point out other things which are wrong - and that is a GOOD THING as that helps all learn without having to ask questions one does not even know to ask.

Keep up your part of the picking apart, we ALL learn from each other doing that.

13. Re: Sizing bonding jumper at water meter

I have no problem at all with people expanding the scope of their answer to any question I ask - the most dangerous questions in this business are the ones you don't even know you're suppose to be asking.

That's why I ask questions like that one: one look at the workmanship and you know that whoever installed that jumper not have to have a "reason" for anything they did, I just wanted to know if there was any conceivable reason I had not considered why it would be reasonable to double-jumper (assuming it was done correctly) such a bond.

(And while you all were at it, I was a bit surprised that no one mentioned the lead supply line.)

14. Re: Sizing bonding jumper at water meter

Originally Posted by Michael Thomas
(And while you all were at it, I was a bit surprised that no one mentioned the lead supply line.)

I didn't (and still don't) see a lead supply line.

I now suspect (after you stated the above) that the part at the bottom which looks like size adapters for galvanized pipe must be lead.

15. Re: Sizing bonding jumper at water meter

By the way, here it is only the end of February, and I think I've already seen my "roof of the year" at this same property...

Last edited by Michael Thomas; 03-02-2010 at 11:15 AM.

16. Re: Sizing bonding jumper at water meter

Table 250.66 givers the proper size bonding wire to be used.
It is based on service conductor size.

17. Re: Sizing bonding jumper at water meter

Well we are on the subject of bonding, grounding, and the aggressively stupid things people do:

From this morning's foreclosure:

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