0 members (),
161
guests, and
10
robots. |
Key:
Admin,
Global Mod,
Mod
|
|
|
Joined: Mar 2006
Posts: 10
OP
Member
|
Thanks gfretwell for your post.
Here in Canada, I tried to get the Canadian equivalent of the UL (here called CSA) to render an opinion on the adequacy of these plates for providing post-construction protection. They did not want to render an opinion and referred me to the local authority who enforces the code.
Comparing the risk of accidentally piercing Romex set back 1-1/4 inches from a stud face without a plate to the risk of piercing Romex installed closer than 1-1/4 inches with the use of a plate is like comparing apples and oranges.
For the first case, the code assumes that the prudent homeowner will never drill to a depth exceeding 1-1/2 inches and for the latter case, the code assumes that the homeowner attempting to drill to the same depth would upon hitting a metal protection plate cease to continue.
In a perfect world, electricians would always be able to route cables deeper than 1-3/4 inches behind the stud face, but in the real world we have been told that the use of a 1/16" metal plate will absolve us of any feeling of responsibility should an accident ever occur.
I guess every installer must establish their comfort level and then decide if they want to accept code or exceed it.
|
|
|
|
Joined: Dec 2003
Posts: 886
Member
|
do you remember how thin your friend's sheet really was?
Pretty thick, better than 1/16" as I remember. Had him punch the screw holes, drilling wouldn't be easy.
-Hal
|
|
|
|
Joined: Mar 2006
Posts: 10
OP
Member
|
Hal,
Thanks for your answer.
I'm sure 1/16 inch or thicker stainless would be next to impossible to drill through without a carbide bit.
Hardness seems to vary with the percentage of nickel in the alloy and that affects how easily the metal retains stains.
If your friend needed a punch, it is probably a hard alloy. If I choose stainless over rolled steel, it will probably be a thinner guage.
I will probably ground the plate as well to the electrical ground so that if a drill bit goes through and hits a wire, at least the breaker will blow instantly.
|
|
|
|
Joined: Feb 2005
Posts: 693
Member
|
I don't think we can protect wires from the determined DIY homeowner toting a drill any better than we could protect them from the same guy armed with a reciprocating saw and the gleam of an addition in his eye.
Larry Fine Fine Electric Co. fineelectricco.com
|
|
|
|
Joined: Mar 2006
Posts: 10
OP
Member
|
Larry,
I agree that I can't protect such a homeowner, but I want to do my part to assure that anytime I place wires buried in a sheetrock ceiling that are 1/2 inch closer to the surface than permitted by code, I, at least provide the mandatory 16 guage steel plate.
When I closed up this art deco style ceiling with its 5 layers,offset at different depths, I never imagined that someone would ever want to hang any object from it.
I even thought if I left a photograph showing the concentration of wires in this ceiling, that would be enough to discourage such a DIY guy from ever attacking it with a drill.
But this house has a good chance of surviving a hundred years, pictures and plans will be lost or ignored, and I have to do the minimum necessary to provide some protection.
Legally, in the deed of sale, I have to have declared that there is a hidden defect in the wiring for which a plate was added to compensate.
|
|
|
Tom
Shinnston, WV USA
Posts: 1,044
Joined: January 2001
|
|
|
|