Water heater grounding jumper

[hurk27]

Re: Water heater grounding jumper

Yes it would Bennie.
As for that matter if only all laws were written in plain English and not all this lawyer hype.
I remember a saying that there is no excuse not to know the law! or ignorance of the law is no excuse. But how are we the average Joe suppose to know the law when it's riddled with wording that a English professors don't understand.

 

[iwire]

Re: Water heater grounding jumper

Originally posted by bennie:
When the water pipe is an electrode, the Table for grounding electrode conductor 250.66 applies.

When bonding the pipe for fault clearing purposes only, the Table 250.122 applies.

#10 and #12 will work fine.

Bennie I agree with your logic but the NEC does not, using table 250.122 for the water pipe bonding jumper will result in a failed inspection.

250.104(A)(1) clearly tells us to use table 250.66 for water pipe bonding jumpers.

 

[bennie]

Re: Water heater grounding jumper

Bob: This is another poorly worded section. The title of the "Table" is the secret message.

250.66 "Grounding Electrode Conductor" for AC Systems.
A grounding electrode conductor can also serve as a bonding conductor.

250.122 Minimum Size "Equipment Grounding Conductor" for Grounding Raceway and Equipment.
An equipment ground conductor is a bonding conductor but not a ground electrode conductor.

 

[don_resqcapt19]

Re: Water heater grounding jumper

Bennie,
It is very clear that the code requires the use of a water pipe bonding conductor sized per Table 250.66 and the size of the service entrance conductors. I have no idea why the code requrires this sizing, but it does and until the code is canged, the use of smaller bonding conductors will result in a red tag.
Don

 

[bennie]

Re: Water heater grounding jumper

I don't read it that way, a bond only is not a grounding electrode conductor. I think the intent is obvious even if the words appear to contradict.

This is another example of the waste and expense created by a code that no one can understand.

 

[ryan_618]

Re: Water heater grounding jumper

Come on Bennie, your overthinking the problem. I agree that it is strange, but the section in question is not poorly worded and its intent is clear.

 

[jxofaltrds]

Re: Water heater grounding jumper

"An equipment ground conductor is a bonding conductor but not a ground electrode conductor."

Using Bennie's words, and I agree, could we use 250.102(D) and 250.104(B)?

"I" believe that 250.104(A) is meant for the origin of the metal water line. Anything after that first( in the above case 3/0) bonding would be "other" metal piping.

I would allow Table 250.122 to apply above for the reasons stated in 250.102(D) and/or 250.104(B).

Go to 250.104(C) for a moment. ....."and is not intentionally grounded". If it were intentionally grounded then the rest of that section does not apply.?

Mike P.

 

[ryan_618]

Re: Water heater grounding jumper

Originally posted by jxofaltrds:
[QB] "
Using Bennie's words, and I agree, could we use 250.102(D) and 250.104(B)?

No. 250.102(D) is for bonding equipment, not piping. 250.104(B) is for "other piping", other as in NOT WATER PIPING.

 

[iwire]

Re: Water heater grounding jumper

I agree with Ryan, there is nothing hard to understand in the wording here.

The water pipe bonding jumper size is determined by 250.66

I do not understand the reason for that but it is clear that is what they are saying.


And Happy Holidays everybody, Bob

 

[bennie]

Re: Water heater grounding jumper

I would like to read an opinion from the code making officials, with an explanation of connecting a 3/0 cu to a water line that is not a ground electrode.

A ground electrode connection must be at the entrance of the water line. A bonding connection can be anyplace accessible. All of the conductors listed in 250.66 will have to be within the first 5 feet of the water line even if that is also the last 5 feet.

How come these sections have remained in the present state so long?

 

[bennie]

Re: Water heater grounding jumper

I have read back to the 1993 Edition. The rule for size of conductor was plainly indicated. The conductor was called equipment ground conductor not bonding conductor. The Table for equipment ground conductors applied.

The meaning and understanding went sideways when the blue ribbon committee changed the text in the 1999 Edition. It appears they mixed grounding for fault purposes with earth grounding to a water pipe.

I always went by the understanding that for equipment grounding for fault clearing was based on the size of the device required to clear the fault.

The size of a ground electrode conductor is based on the service conductors due the amount of current that may appear on the water pipe with the loss of a neutral.

 

[earlydean]

Re: Water heater grounding jumper

I was told that the concern about the cold and hot water pipes was the danger of someone in the shower, in contact with the water pipes and the drain. if there was some sort of fault that took the route through the water pipes, then the clean victim would be in the shower. Hence the requirement for size via 250.66 for the service size bond.

 

[jxofaltrds]

Re: Water heater grounding jumper

After long consideration I have to say that I am wrong in my interpretation of 250.104.

I let what I thought was reasonable skew my thinking.

While I disagree I have to say NOW that the code is clear and the above posters are correct.

Sizing per 250.66 for such a short distance would not cause any financial hardship to anyone.

Mike P.

 

[bennie]

Re: Water heater grounding jumper

250.104 Bonding of Piping Systems and Exposed Structural Steel.

Table 250.66 does apply when the conductor is bonding the various ground electrodes. Read all of 250.104.A.1.

When bonding water pipe when it is not a ground electrode, Table 250.122 applies.

I won't continue to respond to this issue, I am only going in circles. This should be submitted to the panels for an interpretation.

 

[iwire]

Re: Water heater grounding jumper

Bennie 250.104(A)(1) has nothing to do with electrodes.

The only mention of electrodes or electrode conductors conductors is to tell us we can bond the water pipe to the electrode or grounding electrode conductor if it is large enough.

(1) General. Metal water piping system(s) installed in or attached to a building or structure shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or to the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with Table 250.66 except as permitted in 250.104(A)(2) and (A)(3).

That tells us plainly the the water pipe bonding jumper may be at times larger than a grounding electrode conductor as in one going to a ground rod that might be 6 AWG.

I have no idea why the code wants it this way but this is clearly written and easy to understand even if we do not know the reasons behind it.

[ December 25, 2003, 09:47 AM: Message edited by: iwire ]

 

[ryan_618]

Re: Water heater grounding jumper

Originally posted by jxofaltrds:
After long consideration I have to say that I am wrong in my interpretation of 250.104.

I let what I thought was reasonable skew my thinking.

While I disagree I have to say NOW that the code is clear and the above posters are correct.

Sizing per 250.66 for such a short distance would not cause any financial hardship to anyone.

Mike P.

Mike: admitting when you are not right is a difficult thing to do. I just gained a lot of respect for you.

 

[jxofaltrds]

Re: Water heater grounding jumper

"Mike: admitting when you are not right is a difficult thing to do. I just gained a lot of respect for you."

I have had alot of practice. LOL

Thank you.

Mike P.

 

[ryan_618]

Re: Water heater grounding jumper

Originally posted by jxofaltrds:
I have had alot of practice. LOL

Mike P. [/QB]

Me too