Is grounding the gas meter required?

[Eddie702]

CSST is awful. The only thing I ever used it for was a temp connection to a gas fire RTU. There is nothing to it not very substantial. I would run gas in EMT before I would put that stuff in a building. I guess in some parts of the country they do whole houses with it. Non me.

MA actually banned it for a year or so after there were some fires due to lighting strikes......hence the bonding issue came up. MA only allows it for low pressure 1/2lb max=12"WC. In other parts of the country, they allow it for high pressure up to 5 psi.

It's just crazy.

 

[mtnelect]

What I was referring to ... The CSST is not rated for connection inside the furnace by the manufacturer. Also, another "Short Cut" is the use of flexible cords for powering the furnaces.

 

[ramsy]

another "Short Cut" is the use of flexible cords for powering the furnaces.

How are receptacles disqualified as cord & plug disconnect for FAU's per NEC 422.33?

 

[mtnelect]

How are receptacles disqualified as cord & plug disconnect for FAU's per NEC 422.33?

Section 422.16(A) General. Flexible Cord shall be permitted (1) for the connection of appliances to facilitate their frequent interchange or to prevent the transmission of noise or vibration or (2) to facilitate the removal or disconnection of appliances that are fastened in place, where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance or repair and the appliance is intended or identified for flexible cord connection.

Certainly, the gas piping and the size of a gas or electric furnace do not allow for "ready removal" of the furnace. Furthermore, the conductors in flexible cords cannot withstand the high temperature encountered on the terminals of a furnace. ANSI Standard Z21.47 does not allow cord-and plug-connection for gas furnaces.

 

[ramsy]

ANSI Standard Z21.47 does not allow cord-and plug-connection for gas furnaces

Ansi Z21.47 must be adopted before required.

Can't find any NEC, IRC, or IBC reference to our state adopting this, or adopting NFPA-54, in our building code.

Can you provide a link?

 

[ramsy]

Section 422.16(A) General. Flexible Cord shall be permitted

"Shall" is a permissive rule identified in 90.5(B), not to be interpreted as a restriction.

 

[mtnelect]

Ansi Z21.47 must be adopted before required.

Can't find any NEC, IRC, or IBC reference to our state adopting this, or adopting NFPA-54, in our building code.

Can you provide a link?

 

[ramsy]

ANSI Standard Z21.47

Your link does not show who adopts this standard?

ANSI Z21.47 appears to prohibit cord & plugs without strain relief, but AHJ's must have adopted this standard.

 

[ramsy]

Looks like we had this discussion last year.

The last sentence of our discussion shows the ANSI STD allows cord and plug with strain relief.

 

[augie47]

I brought this up at a UL seminar a while back as I could not find a definitive answer in UL LZFE but the answer from UL was twofold:
, "UL has not Listed cord-and-plug connected central air-conditioning equipment or central heating furnaces"
", UL 1995 requires equipment to be marked if cord and plug connected "

In addition, the folks at that seminar felt it was not allowed due to the wording of 400.10 & 400.12 and likely 422.16

 

[gene6]

Does the heater have an electrical connection? If not I don't see how it is "likely to become energized". If it does have an electrical connection, then it is grounded/bonded by the EGC in the circuit serving the heater and nothing additional is required.

Here is one for ya;
Newly renovated house, gas cooktop / electric oven fitted with new gas line, original 50A crows foot receptacle without an equipment gnd was used (code allows that) some other work knocked the utility neutral loose, so a neutral path was via 3-wire range neutral to the flexible gas pipe.

 

[Eddie702]

Here is one for ya;
Newly renovated house, gas cooktop / electric oven fitted with new gas line, original 50A crows foot receptacle without an equipment gnd was used (code allows that) some other work knocked the utility neutral loose, so a neutral path was via 3-wire range neutral to the flexible gas pipe.

How did that work out???

 

[LarryFine]

It's more about bonding around CSST than it is about bonding the meter or the piping.

The appliance end of CSST is bonded by the EGC of the appliance. A nearby lightning strikes can drive current through the CSST by energizing the solid piping connected to the meter end from outside.

By bonding the meter and solid piping to the service EGC/grounding bus, we effectively bond both ends of the CSST together, bypassing the lightning-driven current from traveling through it.

 

[LarryFine]

Here is one for ya;
Newly renovated house, gas cooktop / electric oven fitted with new gas line, original 50A crows foot receptacle without an equipment gnd was used (code allows that) some other work knocked the utility neutral loose, so a neutral path was via 3-wire range neutral to the flexible gas pipe.

Back at ya:
I investigated and wrote a report on a fire in the utility room of a home. It occurred during a storm which caused tree damage which caused a POCO primary to hit secondary and service conductors.

Someone had done a non-permitted-or-inspected service upgrade, and connected absolutely no grounding electrode connections, not even the original ones. They also used no cable clamps, etc.

The EGC in the water-heater cable was the only connection between the service and the plumbing system. The fire was caused by the EGC melting and igniting the filler, sheath, then nearby wood.

 

[electrofelon]

Here is one for ya;
Newly renovated house, gas cooktop / electric oven fitted with new gas line, original 50A crows foot receptacle without an equipment gnd was used (code allows that) some other work knocked the utility neutral loose, so a neutral path was via 3-wire range neutral to the flexible gas pipe.

Ok but would would a separate gas bond wire have done? All it would have done is bonded the gas back to the neutral at the service disconnect, but the neutral was broken upstream anyway.

 

[Eddie702]

In the 3 wire range above current would travel through the gas pipe to earth also through the neutral back to the panel and then to earth through the ground rods and water pipe if the utility wire were open.

I don't see how a 4 wire would change this.

 

[petersonra]

Back at ya:
I investigated and wrote a report on a fire in the utility room of a home. It occurred during a storm which caused tree damage which caused a POCO primary to hit secondary and service conductors.

Someone had done a non-permitted-or-inspected service upgrade, and connected absolutely no grounding electrode connections, not even the original ones. They also used no cable clamps, etc.

The EGC in the water-heater cable was the only connection between the service and the plumbing system. The fire was caused by the EGC melting and igniting the filler, sheath, then nearby wood.

It is unlikely a grounding electrode connection would have changed much. Nothing in the house is designed for MV so it is just going to find the path of least resistance for most of the current and the wires just are not going to be big enough to trip the protection relays on the MV side fast enough to do any good.

 

[tortuga]

Ok but would would a separate gas bond wire have done? All it would have done is bonded the gas back to the neutral at the service disconnect, but the neutral was broken upstream anyway.

Agreed
A combo gas/electric range installed per '250.140 Exception' creates connection between a gas pipe and a neutral, if the gas pipe has any other appliances with a EGC or is bonded again at the meter there is a parallel neutral path.

 

[electrofelon]

In the 3 wire range above current would travel through the gas pipe to earth also through the neutral back to the panel and then to earth through the ground rods and water pipe if the utility wire were open.

I don't see how a 4 wire would change this.

Likely the supply gas piping will be non metallic, and even if it is metallic there is almost always a dielectric fitting. So even with a bonding jumper it will make it back to the service panel and hit dirt thru the ground rods, but that wont do anything other than sit there and give the worms a tingle.

 

[gene6]

In the 3 wire range above current would travel through the gas pipe to earth also through the neutral back to the panel and then to earth through the ground rods and water pipe if the utility wire were open.

I don't see how a 4 wire would change this.

If a 4-wire had been used to the range there would have been no parallel path on the gas pipe for the neutral current as the only N-G bond would be in the service.