Does a metal tin ceiling have to be bonded?

[winnie]

120v to center point of xfmr?

Presumably in addition to actual soil.

Remember we have an intentionally grounded electrical system, and the midpoint of the transformer is connected to earth and all bonded metal.

This means that the transformer ungrounded conductors are at 120V relative to midpoint _and_ soil.

If you have an ungrounded conductor faulted to unbonded metal, that metal will be at 120V relative to soil.

Jon

 

[wyreman]

No, literal earth. Dirt. Ground. One probe into dirt and other onto metal siding. Soil was very moist. Isolated issue to one circuit and turning that off voltage disappeared.

wiggie! =0

I had a good sniffer one time that used a big copper plate in the dirt

 

[Fred B]

wiggie! =0

I had a good sniffer one time that used a big copper plate in the dirt

Not sure what you mean. My helper had gotten zapped off the door handle on the metal trailer door. That is why I tested. A wiggie wouldn't have changed that. Even showed as hot with the hot stick.

 

[wyreman]

I had a wire tracing / pipe tracing tool at work one time, looked like a metal detector
One alligator went to a big copper plate you had to wedge down in the earth, the other alligator went to the wire or pipe.
and then you could ring the pipe pretty good.
I'm agreeing with you.

I had lots of those where someone gets zapped by touching two things.
What two things was your helper touching? door handle and... barefoot?

 

[brantmacga]

A different inspector came for my final, and didn’t mention anything about bonding the tin ceiling.

And it turned out pretty nice !

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[gadfly56]

A different inspector came for my final, and didn’t mention anything about bonding the tin ceiling.

And it turned out pretty nice !

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Looks very nice! Is the tin we see also the functional roof? I ask because I see a lot of rust on the panels. Which is fine for ambience if it's not part of the weather envelope.

 

[Bjenks]

I put this in my general wire methods and material notes. I do this because I have had many plan reviewers ask me to make sure the contractor is aware so now I just put it as part of my notes. It is part of the Florida Building Code and is really more about metal framing that can be energize when a drywaller put a screw in the electric and touches the metal framing but if you are running romex up there I can see where they would require it, but just put a metal j-box up there and have it touch the roof:
"METAL FRAMING MEMBERS SHALL BE BONDED TO THE EQUIPMENT GROUNDING CONDUCTOR FOR ANY CIRCUIT THAT MAY ENERGIZE THE BUILDING FRAMING AND BE SIZED IN ACCORDANCE WITH THE NATIONAL ELECTRIC CODE, TABLE 250.122. FOR THE PURPOSE OF THIS REQUIREMENT, A GROUNDED METAL OUTLET BOX ATTACHED TO THE FRAMING SHALL BE PERMITTED"

 

[brantmacga]

Looks very nice! Is the tin we see also the functional roof? I ask because I see a lot of rust on the panels. Which is fine for ambience if it's not part of the weather envelope.

No, this tin is on the bottom of wood trusses, standing seam metal roof on top.

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[brantmacga]

I put this in my general wire methods and material notes. I do this because I have had many plan reviewers ask me to make sure the contractor is aware so now I just put it as part of my notes. It is part of the Florida Building Code and is really more about metal framing that can be energize when a drywaller put a screw in the electric and touches the metal framing but if you are running romex up there I can see where they would require it, but just put a metal j-box up there and have it touch the roof:
"METAL FRAMING MEMBERS SHALL BE BONDED TO THE EQUIPMENT GROUNDING CONDUCTOR FOR ANY CIRCUIT THAT MAY ENERGIZE THE BUILDING FRAMING AND BE SIZED IN ACCORDANCE WITH THE NATIONAL ELECTRIC CODE, TABLE 250.122. FOR THE PURPOSE OF THIS REQUIREMENT, A GROUNDED METAL OUTLET BOX ATTACHED TO THE FRAMING SHALL BE PERMITTED"

Its wood framing. The tin is just sheathing on wood trusses.

 

[jap]

That's frickin beautiful.

JAP>

 

[brantmacga]

That's frickin beautiful.

JAP>

I agree. Everyone did a really nice job. There was a little more to the overall project than just that building. There’s a bunk house we added, and the larger main residence was built 5/yrs ago. I did some additional work adding wired networking between all the structures, Luxul router and AP’s at each structure, and Sonos audio.

Here’s a video I took yesterday playing with the audio.

https://imgur.com/a/cshNTzt

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