Gas Fireplace Grounding
- Thread starter xelatj
- Start date
- Status
know the size of conductor for grounding a gas fireplace with no electrical hookup.
- Location
- Massachusetts
Re: Gas Fireplace Grounding
What size breaker is likely to energize this unit?
What size breaker is likely to energize this unit?
bphgravity
Senior Member
- Location
- Florida
Re: Gas Fireplace Grounding
I believe what Bob is getting at is the allowance of Section 250.104(B).
I believe what Bob is getting at is the allowance of Section 250.104(B).
- Location
- Massachusetts
Re: Gas Fireplace Grounding
Yes I was aiming at that and grounding and bonding in general.
Supply side of the service 250.66 by conductor size or on the load side of the service 250.122 by the OCPD.
Why do you need to bond this unit?
If you do decide to bond it you will need to decide what the rating of the circuits are that are likely to energize the unit.
Yes I was aiming at that and grounding and bonding in general.
Supply side of the service 250.66 by conductor size or on the load side of the service 250.122 by the OCPD.
Why do you need to bond this unit?
If you do decide to bond it you will need to decide what the rating of the circuits are that are likely to energize the unit.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: Gas Fireplace Grounding
I'm not sure that we could use 250.104(B), since the fireplace isn't "other metal piping"...its just a fireplace.
As far as that goes, I think you could use 250.4(A)(5) to argue it if it were likely to become energized, which in my opinion it is not. A fireplace without an electrical source is no more likely to become energized that towel bar in a bathromm is, and I'm certainly not going to bond all of those.
Just my opinion.
I'm not sure that we could use 250.104(B), since the fireplace isn't "other metal piping"...its just a fireplace.
As far as that goes, I think you could use 250.4(A)(5) to argue it if it were likely to become energized, which in my opinion it is not. A fireplace without an electrical source is no more likely to become energized that towel bar in a bathromm is, and I'm certainly not going to bond all of those.
Just my opinion.
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
Re: Gas Fireplace Grounding
This makes me think about a time when we were working on brand new townhouses. Adjacent units had back to back Heatalator (sp?) type fireplaces. These each had metal stacks up through the roof right next to each other. They also had forced air fans controlled by a wall switch which was on the living room receptacle circuit.
When we istalled the breakers and energized the living room circuits in both those units there was a dead short. The breakers tripped immediately. Thinking it very unusual that this would happen on the same circuit in adjacent units, we opened the boxes and cut open the sheetrock and found that the NM was both burnt and kind of looked like mice had chewed from both conductors to the ground every 1/4 inch or so. This was for the entire 30' length along a wall from the fireplaces, and into some of the other wiring in the units. This was EXACTLY the same in both units (both units were wired the same way).
We originally thought mice but that would not explain the burned insulation since the breaker tripped immediately and we didn't try it again.
Ultimately we realized that this was caused by lightning. Indeed there had been heavy thunderstorm activity in the area and apparently a close strike flashed to both metal stacks. Why it did what it did to the NM is anybodies guess (lightning DOES do strange things) but consider that the equipment ground was connected at the panel as well as the neutral.
Point of this story is that I would consider something larger than a #14 or #12 ground bond.
-Hal
This makes me think about a time when we were working on brand new townhouses. Adjacent units had back to back Heatalator (sp?) type fireplaces. These each had metal stacks up through the roof right next to each other. They also had forced air fans controlled by a wall switch which was on the living room receptacle circuit.
When we istalled the breakers and energized the living room circuits in both those units there was a dead short. The breakers tripped immediately. Thinking it very unusual that this would happen on the same circuit in adjacent units, we opened the boxes and cut open the sheetrock and found that the NM was both burnt and kind of looked like mice had chewed from both conductors to the ground every 1/4 inch or so. This was for the entire 30' length along a wall from the fireplaces, and into some of the other wiring in the units. This was EXACTLY the same in both units (both units were wired the same way).
We originally thought mice but that would not explain the burned insulation since the breaker tripped immediately and we didn't try it again.
Ultimately we realized that this was caused by lightning. Indeed there had been heavy thunderstorm activity in the area and apparently a close strike flashed to both metal stacks. Why it did what it did to the NM is anybodies guess (lightning DOES do strange things) but consider that the equipment ground was connected at the panel as well as the neutral.
Point of this story is that I would consider something larger than a #14 or #12 ground bond.
-Hal
- Status