mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
There was a happy no head emoji on this site, and they took that away
I know, I know, import your own but veterans of this site still miss them.
Does a metal tin ceiling have to be bonded?
- Thread starter brantmacga
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There was a happy no head emoji on this site, and they took that away
I know, I know, import your own but veterans of this site still miss them.
mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
I remember Mike a while back saying that without a bond there was absolutely no way something could become energized, but by running a copper wire and connecting it to anything metal you now risk the possibilty of energizing that metal.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Personally I feel that 'likely to become energized' applies if there are fixtures mounted on or near the ceiling or cables run on or near the ceiling (being vague with the 'near').
NM cable run tucked to the metal is at risk from panel edges or fasteners, for example, and such a panel should be bonded IMHO.
But if there is nothing to energize the panel, then why bond?
Jon
NM cable run tucked to the metal is at risk from panel edges or fasteners, for example, and such a panel should be bonded IMHO.
But if there is nothing to energize the panel, then why bond?
Jon
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
I can see the guy going up to patch the roof with his aluminum ladder getting zapped by voltage that wouldn't have been there if it wasn't bonded.
I think the reasoning for "if likely to become energized" criteria is that there would be a circuit associated that would trip if a fault to the metallic material was to occur rather than just random NEV.
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
It seems to me I recall a code requirement that prohibits the electrical within x# of inches of a metal roof structure. That would if complied with limit the chance of incidentally energizing the roof panels.
mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
Agree, it almost seems (IMO) like this is one of risk vs benefit. 120 volts is worse than 3 volts, but ultimately 0 volts is better than 3 volts.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Here in NY, NYSERDA which approves and provides PV incentives requires metal roofing to be bonded. They are not the AHJ, and the inspectors don't require it, but NYSERDA can withhold your $$$$. ( I think it is silly).
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
That refers to the emoji of a smiling face shaking head no. It is not on the default emoji menu under the new software.
Under the old software, the mouse over of the emoji is "happy no". It was paired with "happy yes" shaking head vertically.
Id say if you have a proper EGC installed and attached to the light fixtures that are mounting on the metal sheets where the outlet boxes are, the circuit should trip if there's any short to ground, so, the sheets will not be energized in case of a fault.
The sheets that don't have any electrical installed on them aren't likely to become energized and I don't see the need for those to be bonded.
If you do crappy work, and , don't install a sufficient EGC to the outlet boxes where the fixtures will be mounted to the tin, then, I'd say if a short occurred in the fixtures, the tin would likely become energized to a hazardous degree, and, You'd better get to bonding.
JAP>
The sheets that don't have any electrical installed on them aren't likely to become energized and I don't see the need for those to be bonded.
If you do crappy work, and , don't install a sufficient EGC to the outlet boxes where the fixtures will be mounted to the tin, then, I'd say if a short occurred in the fixtures, the tin would likely become energized to a hazardous degree, and, You'd better get to bonding.
JAP>
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
I've spoken to a couple of installers who are finding themselves stuck between the code and NYSERDA. If they install per code as you say they call it and withhold the funding, if they install per NYSERDA it's a code violation.
K8MHZ
Senior Member
- Occupation
- Electrician
Then we should also require that metal ladders be bonded before use.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
What is the code violation to bonding metal roofing? While I agree that it isn't required in most situations, I don't see doing so as prohibited.
-Jon
Let's say we're dealing with a large metal roof and siding installed on wooden studs and rafters.
What would an electrician's procedure be to bond each and every sheet of metal on this wood framed structure ?
To me it would have to be a roof installers responsibility to assure bonding of the complete structure seeing as how it's going to depend on the installation practices and fasteners being used while the sheet metal is being installed.
JAP>
What would an electrician's procedure be to bond each and every sheet of metal on this wood framed structure ?
To me it would have to be a roof installers responsibility to assure bonding of the complete structure seeing as how it's going to depend on the installation practices and fasteners being used while the sheet metal is being installed.
JAP>
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
Not referencing the roof as that issue but other points NYSERDA inspector is calling.
But AFA the roof, there is one NYSERDA inspector I've been told has been demanding bonding on every single metal roof sheet and each ridge cap section. Ignoring that the tracking connections are using the self bonding hold down that bolts them to the roof.
rc/retired
Senior Member
- Location
- Bellvue, Colorado
- Occupation
- Master Electrician/Inspector retired
I’m working on a cook shed for a friend; the ceiling is tin with recessed lighting.
He told me today the inspector had mentioned something about bonding the tin.
Is there an NEC requirement for this?
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Barring any local amendments, there are no code requirements to bond a tin roof. JMHO and then some.I’m working on a cook shed for a friend; the ceiling is tin with recessed lighting.
He told me today the inspector had mentioned something about bonding the tin.
Is there an NEC requirement for this?
Sent from my iPhone using Tapatalk
Ron
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
I have never done it but my old boss 45 years ago talked about bonding aluminum siding on houses at the corners
brantmacga
Señor Member
- Location
- Georgia
- Occupation
- Former Child
I’ve worked on houses with energized aluminum siding .
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Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
Worst I've encountered is 120V to earth on a mobile home metal siding.
120v to center point of xfmr?
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
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.
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