Bonding Continuity Metal Pipe (250.53.D.1)

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jay

New member
The bonding and ground path must be continuous. The continuity must not rely on meters, filters, or other devices. A jumper must be installed. IAEI states that the ground path should be permanent.

?? Is each break in pipe such as at each valve, union, coupling, etc. then required to have a jumper cable throughout the entire facility. Is a pipe connection which the manufacturer states is electrically continuous without a jumper acceptable? UL does note test pipe fittings for continuity as far as I know.
 

bennie

Esteemed Member
Re: Bonding Continuity Metal Pipe (250.53.D.1)

The first 5 feet, of water pipe, is designated as a ground bus for ground electrode connection and bonding. There should not be a dielectric fitting within the 10 feet required, for the pipe, to meet the definition of a ground electrode.
 

bennie

Esteemed Member
Re: Bonding Continuity Metal Pipe (250.53.D.1)

The original requirement for connecting to the water pipe for a ground electrode, was to connect on the dirt side of the meter.

With meters being some distance away, the requirement changed to the 5 foot rule. The meter was then to be jumpered if 10 feet of pipe minimum was not in the dirt.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Bonding Continuity Metal Pipe (250.53.D.1)

Bennie,
Before the '93 code, you could connect the grounding electrode conductor to the water pipe anywhere. The 5' rule was added in the '93 code because of the possiblility of a nonmetallic pipe repair fitting being used between the metal underground water pipe and the point of connection for the grounding electrode conductor.
Don
 

don_resqcapt19

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Staff member
Location
Illinois
Occupation
retired electrician
Re: Bonding Continuity Metal Pipe (250.53.D.1)

Jay,
The bonding rule in 250.104 does not require jumpers around every valve, joint or fitting. It would require jumpers to sections of metallic water piping that are isolated by sections of nonmetallic piping. The grounding connection must be within 5' of the water pipe's entrance to the building and a bonding jumper is used around the water meter.
Don
 

bennie

Esteemed Member
Re: Bonding Continuity Metal Pipe (250.53.D.1)

Don: The supplemental ground electrode is for grounding when the water pipe is lost.

The 5 foot limitation is to prevent load, and transient current, from appearing on all the piping system.

This procedure also prevents a potential voltage when changing the water heater, depending on where connection is made.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Bonding Continuity Metal Pipe (250.53.D.1)

Bennie,
I just looked up the substantiation for the change in the '93 code. The only reason for this change was the possibility of a nonconductive water pipe repair. The change may have other benefits, but they were not the reason for the change.
Don
 

bennie

Esteemed Member
Re: Bonding Continuity Metal Pipe (250.53.D.1)

Don: I read somewhere that the 5 foot was for bonding all the electrodes to make them one electrode.

The possible replacement of metal piping was directed to the underground water service, which eliminated the water pipe as an electrode.

This repair was not intended for the premises piping. Planning for what might happen, is not in the scope of the NEC. The 5 foot area for bonding is to provide ease of verification that a supplement exists.
 

hurk27

Senior Member
Re: Bonding Continuity Metal Pipe (250.53.D.1)

This repair was not intended for the premises piping. Planning for what might happen, is not in the scope of the NEC.
Then why the careful wording of the exception to 250.52 (A)(1)?
where conditions of maintenance and supervision ensure that only qualified persons service the installation, interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall be permitted as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system,

[ May 02, 2003, 01:12 AM: Message edited by: hurk27 ]
 

bennie

Esteemed Member
Re: Bonding Continuity Metal Pipe (250.53.D.1)

Qualified persons will know what the ground clamps and conductors are for, and their location.

Have you seen interior piping in a commercial or industrial occupancy changed to plastic?

I have never seen one, but I have seen a lot of the water services changed to PVC.
 

jbell59

Member
Location
Virginia
Re: Bonding Continuity Metal Pipe (250.53.D.1)

"The first 5 feet, of water pipe, is designated as a ground bus for ground electrode connection and bonding"

If the water pipe is used as a grounding electrode then yes the GEC connection has to abide by the 5' rule, however if just bonding the the water piping system(doesn't qualify for GE) then the bonding connection can be done anywhere on the piping system.

I believe the 5' rule is used not only to bypass any plastic(if in system) but also for safety reasons. Say plumber is making repairs after the GEC connection (breaking the electrode)and there's fault on the GEC. Let's say this wouldn't be the plumber's day.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Bonding Continuity Metal Pipe (250.53.D.1)

Bennie,
The 5' rule was speciffically because of the possibility of a nonmetallic replacement/repair of the interior metal water pipe between the point of the grounding electrode connection and the water pipe's entrance to the building. This information is straight from the 2002 ROP.
Don
 

bennie

Esteemed Member
Re: Bonding Continuity Metal Pipe (250.53.D.1)

The ROP's from 1992 are the ones when the 5 foot limit was put in the code.

A lot of the subsequent proposals quote the plastic pipe scenario. The code has dealt with the plastic pipe in requiring bonding around the non-conductive section.

Until I can read the 1992 ROP's, I will continue to believe the pipe repair explanation is someones fabrication to explain something they don't know anything about.
 
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