Bonding...grounding?????

Status
Not open for further replies.
P

pmoney44

Member
Location
MASSACHUSETTS
200 amp service...do you have to ground water and gas lines??? or just one and do you have to ground gas at point of entry of house...or anywhere in line??
 
250-104 B STATES shall be bonded at service equipment enclosure,grounded service conductor at service and other grounding electrode....that means meter, panel, and water then to gas line??????
 
Gas line to be bonded

Gas line to be bonded

Here in PA the AHJ wants the gas bonded per 250.104(B) after the meter so that the gas line in the house is bonded but the gas line outside the house, before the gas meter, is not used as a grounding electrode for the house grounding system per 250.52(B)(1).

I jump an appropriate sized wire from the gas line to the closest copper cold water line to the gas line.
 
Last edited:
pmoney44 said:
so bascially you only have to run a #4 copper to the water...then jumper to the gas
Click to expand...

Yes, if the metal underground water pipe system meets the criteria of 250.52(A)(1) and is used as a Grounding Electrode then Table 250.66 would be used to size the grounding electrode conductor to a #4 copper, if the largest ungrounded service entrance conductor is either copper (2/0 or 3/0) or Al or Cu clad Al (4/0 or 250), then the bonding jumper to the gas line from the water line per 250.104(B) would be sized to a minimum of copper #6 or Al #4 by Table 250.122 for a 200A breaker. A supplemental Grounding Electrode (a ground rod for example) to the metal underground water pipe would still be required per 250.53(D)(2) with a grounding electrode conductor sized by Table 250.66 (copper #4 in this instance).

Of course you should verify all that for yourself before doing any work, but that's the way I interpret the 2008 NEC on this matter.:)
 
Nium said:
), then the bonding jumper to the gas line from the water line per 250.104(B) would be sized to a minimum of copper #6 or Al #4 by Table 250.122 for a 200A breaker. A supplemental Grounding Electrode (a ground rod for example) to the metal underground water pipe would still be required per 250.53(D)(2) with a grounding electrode conductor sized by Table 250.66 (copper #4 in this instance).
Click to expand...


The NEC does not require a bonding jumper to gas piping.


You do not need to run anything larger than #6cu to a ground rod.
 
Nium said:
I jump an appropriate sized wire from the gas line to the closest copper cold water line to the gas line.
Click to expand...

I find a couple of problems with this.

1. 250.104(B) says 'gas piping that is likely to become energized shall be bonded...

2. ...to the service equipment enclosure, the grounded conductor at the service, the GEC where of sufficient size, or the one or more grounding electrodes used.'

Even if you have a 'likely to become energized' scenario, going to the closest copper cold water line would probably not meet the requirements of 250.104(B) [you would have to make this water pipe connection within 5 ft. of the water line entering the structure].

Moving on...the 2nd to last sentence in 250.104(B) permits the EGC for the circuit that is 'likely to energize' the piping to serve as the bonding means.

What exactly is happening at this structure that establishes a 'likely to become energized' situation? If an inspector is going to require bonding of the gas piping, then he should identify what hazard exists that makes this bonding necessary. Once he has so identified the hazard, then the EGC for the circuit should satisfy the requirementy. Only if no EGC exists for the circuit creating the 'likelihood' is a separate bonding conductor necessary.
 
dana1028 said:
1. 250.104(B) says 'gas piping that is likely to become energized shall be bonded...
Click to expand...

Hence why I interpret the code to mean the gas pipeline shall be bonded as there is no guidance on what likely to become energized is suppose to mean. Gas pipes are metal corrugated or cast iron and can become energized by an ungrounded conductor coming into contact with them.

2. ...to the service equipment enclosure, the grounded conductor at the service, the GEC where of sufficient size, or the one or more grounding electrodes used.'

Even if you have a 'likely to become energized' scenario, going to the closest copper cold water line would probably not meet the requirements of 250.104(B) [you would have to make this water pipe connection within 5 ft. of the water line entering the structure].
Click to expand...

...or the one or more grounding electrodes used doesn't say has to be within 5 feet of entrance. Taking into consideration the metal water pipe is being used as grounding electrode and not just being bonded to the grounding electrode.

Moving on...the 2nd to last sentence in 250.104(B) permits the EGC for the circuit that is 'likely to energize' the piping to serve as the bonding means.
Click to expand...

Since the wording likely to energize is so ambiguous it can mean the gas fired dryer, gas water heater, gas range/oven, or the service entrance cable. I'd have to respectfully argue how can it be said that the gas pipe isn't likely to be energized? Sure we all do everything possible to prevent accidents from happening but that doesn't mean they don't and isn't that what the code is trying to prevent. Accidents turning into deaths.

What exactly is happening at this structure that establishes a 'likely to become energized' situation? If an inspector is going to require bonding of the gas piping, then he should identify what hazard exists that makes this bonding necessary. Once he has so identified the hazard, then the EGC for the circuit should satisfy the requirements. Only if no EGC exists for the circuit creating the 'likelihood' is a separate bonding conductor necessary.
Click to expand...

Electricity in the same structure as gas piping.:D

I appreciate anyone taking the time to reply to a post I've made and try my best not to offend or take offense so if you feel I'm wrong, ok. I just hope everyone does their best to make safe installations and not cut corners.

I'm willing to concede that the statement "likely to be energized" in 250.104(B) is very ambiguos, but as pointed out in "Soares Book on Grounding and Bonding" "Because metal piping systems are conductive, bonding all of them will provide additional safety."
 
Nium said:
I'm willing to concede that the statement "likely to be energized" in 250.104(B) is very ambiguos, but as pointed out in "Soares Book on Grounding and Bonding" "Because metal piping systems are conductive, bonding all of them will provide additional safety."
Click to expand...

I disagree totaly.

Likely: Probably or apparently destined

In my view Likely to become energized means that in WILL become energized at some point. Nobody can predict that it will happen and in fact it is likley that it will not become energized.

No bonding required.
 
Nium said:
Since the wording likely to energize is so ambiguous it can mean the gas fired dryer, gas water heater, gas range/oven, or the service entrance cable. I'd have to respectfully argue how can it be said that the gas pipe isn't likely to be energized? Sure we all do everything possible to prevent accidents from happening but that doesn't mean they don't and isn't that what the code is trying to prevent. Accidents turning into deaths.
Click to expand...

What are you wiring with uninsulated wiring? Do you really do an installation and think "this is going to fail"? Either way the NEC allows the circuit EGC to serve as the bonding means so there is no need for and addtional larger bonding conductor.
 
gas pipes starting fires

gas pipes starting fires

A little off the subject just wondering if anybody else has ran across this, we have investigated a couple fires that were caused by the flexable gas pipes.
Lightning creates tiny holes in the flex and after that one good hit and is all it takes. Also The flex that started the fires were made by different manufactures
 
jeffhornsby said:
A little off the subject just wondering if anybody else has ran across this, we have investigated a couple fires that were caused by the flexable gas pipes.
Lightning creates tiny holes in the flex and after that one good hit and is all it takes. Also The flex that started the fires were made by different manufactures
Click to expand...

This is now recognized as a real problem with CSST. The attached is an interesting document:
http://www.toolbase.org/pdf/techinv/csst_lightningconcerns.pdf

Many installs now require proper bonding to the gas manifold.
 
Nium:
In reference to "...or the one or more grounding electrodes used doesn't say has to be within 5 feet of entrance. Taking into consideration the metal water pipe is being used as grounding electrode and not just being bonded to the grounding electrode." although the method you describe (connecting to the nearest cold water line) is commonplace here and accepted, I believe Dana is correct in that 250.52(A)(1) states in part
" 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.".
To connect to the water line beyond the initial 5 ft would not be connecting to a grounding electrode.
 
Status
Not open for further replies.
Top