CSST Bonding, Existing Structures

[karlr]

I have several existing structures that have CSST gas piping installed in the buildings, in each case the structures are Condo buildings with separate gas meters for each tenant and public service. The CSST is not bonded other than by the EGC (i.e. gas furnace). NEC states that this is acceptable in 250.104 (B). However, 110.3 (B) supersedes this, the manufactures listed and labeling instructions state "This bonding point must be in as close proximity to the electrical panel as possible; close proximity of the bonding point to the gas meter is also desirable if possible. The wire gauge for bonding must be sized, at a minimum, for the full amperage available through the electrical service (per NECR) and no smaller than a 6 AWG copper wire." In addition NFPA 54 7.13.2 also states that it should be bonded.
Here are my questions as it pertains to an existing installation: a) is it required to go back and install the bond on a structure that this was installed before the changes and additions were made by the manufacture or NFPA 54? b) Sizing of the bonding conductor, how should this be sized; by the size of the main service for the building or by each tenants service? c) lastly, my intent is to use the building steel as the bonding point and setting a ground plate at the meter racks (81 meters totals, arranged on 4 racks) how do I go about sizing the bonding conductor to the steel, and can I run a continuous jumper on each rack landing it on the tenant side of each meter, if so how do I size that bonding conductor?
This is a thorn in which I want to remove, any help and input would be greatly appreciated on this subject.
Thank you,

 

[George Stolz]

I have several existing structures that have CSST gas piping installed...

a) is it required to go back and install the bond on a structure...?

Not unless the AHJ requires it. Why are you involved?

b) Sizing of the bonding conductor, how should this be sized; by the size of the main service for the building or by each tenants service?

Whatever the plumbers instructions say. Usually a #6 or a #4 does it.

c) lastly, my intent is to use the building steel as the bonding point and setting a ground plate at the meter racks (81 meters totals, arranged on 4 racks) how do I go about sizing the bonding conductor to the steel, and can I run a continuous jumper on each rack landing it on the tenant side of each meter, if so how do I size that bonding conductor?

Typically what I have done with multiple gas meters is connect to each CSST fitting closest to the gas meter with a single #4, without splice, and then run that single conductor up to steel. Then, send a bill to the plumber (after demanding beer on site).

 

[karlr]

George, thanks for your reply. To answer your question, one of tenants brought it up to the board (HOA) since we take care of the maintenance in the buildings, they approached me. I appreciate the advice on grounding each individual meter to the steel, I hadn't considered that.

 

[jxofaltrds]

I have several existing structures that have CSST gas piping installed in the buildings, in each case the structures are Condo buildings with separate gas meters for each tenant and public service. The CSST is not bonded other than by the EGC (i.e. gas furnace). NEC states that this is acceptable in 250.104 (B). However, 110.3 (B) supersedes this, the manufactures listed and labeling instructions state "This bonding point must be in as close proximity to the electrical panel as possible; close proximity of the bonding point to the gas meter is also desirable if possible. The wire gauge for bonding must be sized, at a minimum, for the full amperage available through the electrical service (per NECR) and no smaller than a 6 AWG copper wire." In addition NFPA 54 7.13.2 also states that it should be bonded.
Here are my questions as it pertains to an existing installation: a) is it required to go back and install the bond on a structure that this was installed before the changes and additions were made by the manufacture or NFPA 54? b) Sizing of the bonding conductor, how should this be sized; by the size of the main service for the building or by each tenants service? c) lastly, my intent is to use the building steel as the bonding point and setting a ground plate at the meter racks (81 meters totals, arranged on 4 racks) how do I go about sizing the bonding conductor to the steel, and can I run a continuous jumper on each rack landing it on the tenant side of each meter, if so how do I size that bonding conductor?
This is a thorn in which I want to remove, any help and input would be greatly appreciated on this subject.
Thank you,

Several things.

1st the NEC does not require this 'additional' bonding.

You cited:
(B) Installation and Use. Listed or labeled equipment
shall be installed and used in accordance with any instructions
included in the listing or labeling.

Equipment. A general term, including fittings, devices, appliances,
luminaires, apparatus, machinery, and the like used as a
part of, or in connection with, an electrical installation.

So the NEC does not apply.

CSST is a plumbing/fuel/gas issue.

Last and most important is that most states have what is called ex post facto.

So unless it is UNSAFE/IMMINENT (some will happen in the next 5 minutes or so) do not worry about it.

 

[George Stolz]

George, thanks for your reply. To answer your question, one of tenants brought it up to the board (HOA) since we take care of the maintenance in the buildings, they approached me. I appreciate the advice on grounding each individual meter to the steel, I hadn't considered that.

I was saying the opposite - catch them all at once with a single conductor.

I agree with Mike on this issue. They can pay to have it fixed and it's a good idea, but I don think there is a legal reason to force the correction.