5ft rule

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jca0108

Member
In 250.52(A)(1) it talks about a 5ft rule. The "point of entrance" refers to what, the water,or my service entrance conductors? I think its the water but i might be wrong. I also know that I still have to bond it as required by 250.104(A).
 

kwired

Electron manager
Location
NE Nebraska
copied from 2008 NEC:
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.

I do not see much confusion in the wording here. The subject of this sentence is "interior metal water piping" and it is further described as what portion of this interior piping "5 ft from the point of entrance to the building" followed by the rest of the instruction.
 

raider1

Senior Member
Staff member
Location
Logan, Utah
I agree with kwired, the point of entrance mentioned in 250.52(A)(1) is referring to the point at which the water pipe enters the building.

Chris
 
The 5' refers to the water service. Your water service enters the building somewhere. 5' after that, it is no longer a grounding electrode. That means that you cannot make your grounding electrode connection further than 5' from where the water service enters the building.

I wonder how many here on the forum agree that if you are using the water service as a grounding electrode you don't have to do anything else to bond your interior metal water pipe???
 

kwired

Electron manager
Location
NE Nebraska
I wonder how many here on the forum agree that if you are using the water service as a grounding electrode you don't have to do anything else to bond your interior metal water pipe???

only if it is electrically continuous other wise you need bonding jumpers around insulating components
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I wonder how many here on the forum agree that if you are using the water service as a grounding electrode you don't have to do anything else to bond your interior metal water pipe???

Of course, unless there is a meter with a dielectric fitting between the main and the water pipes in the house or something similar
 

jca0108

Member
The 5' refers to the water service. Your water service enters the building somewhere. 5' after that, it is no longer a grounding electrode. That means that you cannot make your grounding electrode connection further than 5' from where the water service enters the building.

I wonder how many here on the forum agree that if you are using the water service as a grounding electrode you don't have to do anything else to bond your interior metal water pipe???

I've never felt comfortable using the water pipe as an electrode for many reasons but the code says we can use it(personal opinion).
 

raider1

Senior Member
Staff member
Location
Logan, Utah
but if i use ground rods , is 2 ground rods max to supplement the under grd water pipe(250.56)?

Yes, if you use a ground rod to supplement the water pipe electrode the ground rod must meet the 25 ohm rule or it must be augmented by an additional electrode in accordance with 250.56.

Chris
 

jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
I am with jxofaltrds on that. Bonding the hot water system to the cold, bonding around water softeners, meters, water tanks, etc. is needed to meet 250.104(A).

Be careful I got bashed on the hot/cold bond.

I know that this is how we do it in central Ohio but many here disagree.
 
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jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
Yes, if you use a ground rod to supplement the water pipe electrode the ground rod must meet the 25 ohm rule or it must be augmented by an additional electrode in accordance with 250.56.

Chris

250.56 does not require a 2nd ground rod, if the waterline IS an electrode.

It is an electrode under 250.53(D)(2).

I know that you are going to say that 250.56 requires a second ground rod but it does not.

250.56 'may' (25 ohms or less) take you back to 250.52(A)(4) though (8).

250.52(A)(6) can apply to the waterline, see listed in article 100, so it is the additional electrode.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
250.56 does not require a 2nd ground rod, if the waterline IS an electrode.

It is an electrode under 250.53(D)(2).

I know that you are going to say that 250.56 requires a second ground rod but it does not.

250.56 'may' (25 ohms or less) take you back to 250.52(A)(4) though (8).

250.52(A)(6) can apply to the waterline, see listed in article 100, so it is the additional electrode.


Are you saying that a single rod can qualify as a supplemental electrode even if it doesn't meet the 25 ohms or less rule?
 

Volta

Senior Member
Location
Columbus, Ohio
Be careful I got bashed on the hot/cold bond.

I know that this is how we do it in central Ohio but many here disagree.
I know, but it is clear that the hot must be bonded, I don't know that anyone is arguing that, it is the method that is in dispute, as I remember. Some count on the plumbing fixtures for the bonding. Some claim that there is only one water piping system in a building, so only one bond is needed. The NEC is not concerned with the division of water piping systems, if it is metal, it is to be bonded with jumper(s) sized in accordance with 250.66. Not a faucet assembly. :)
250.56 does not require a 2nd ground rod, if the waterline IS an electrode.

It is an electrode under 250.53(D)(2).

I know that you are going to say that 250.56 requires a second ground rod but it does not.

250.56 'may' (25 ohms or less) take you back to 250.52(A)(4) though (8).

250.52(A)(6) can apply to the waterline, see listed in article 100, so it is the additional electrode.

I don't think that 250.52(A)(6) can be used to allow the underground water pipe as the additional electrode of (4) through (8).

1. The word "Other" must refer to something not present in the preceeding list.
2. 250.53(D)(2) clearly directs us to the 25 ohm rule, which is to be complied with when the rod, pipe, or plate electrode is used to supplement the water pipe.
 
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