Can you use a metallic cover on a plastic box? The scenario I'm thinking of would be a weatherproof plastic box with GFI's and a metallic in use cover. My thinking is that there would be a bonding issue with the cover. I don't have a cover in front of me. I suppose if the GFI mounts to the cover it would be bonded. But to code? I'm unsure where to peruse in the code book to find this.
Metallic Cover on a Plastic Box?
- Thread starter wawireguy
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cripple
Senior Member
- Location
- Santa Fe, New Mexico
Metallic Cover on a Plastic Box?
Section 406.5(B) requires matel faceplates to be grounded, this requirement is met by attaching the equipment grounding conductor to the yoke of the receptacle.
Section 406.5(B) requires matel faceplates to be grounded, this requirement is met by attaching the equipment grounding conductor to the yoke of the receptacle.
- Location
- Simi Valley, CA
If the cover screws to the yoke, it's probably bonded.
- Location
- Logan, Utah
Or it's bonded by being screwed onto a metallic box that is bonded. I just like to dot my i's and cross my t's.
I just thumbing through the NEC and saw that if you have a gasket that is 1/32 or more insulating a cover you don't have to bond a metallic cover. Can't for the life of me locate that reference again.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Sometimes, you have to be inventive:
mcclary's electrical
Senior Member
- Location
- VA
Last edited:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I have "these," but, I made "that" on the computer using PSP. :grin:
mcclary's electrical
Senior Member
- Location
- VA
Ruh,ro Rastro..I have installed a violation then...at our Ren Festival site I put a metal single-gang blank cover on a plastic box over an unused switch location...and I didn't bond it to the ecg....Oh the humanity....:roll: :grin:
I'm not losing sleep over it.
I'm not losing sleep over it.
Forgive me moderator for I have sinned. It has been three weeks since my last confession . . . :grin:
Dave58er
Senior Member
- Location
- Dearborn, MI
:grin:
I got cited by an inspector for the first time for doing this exact thing.
It was a friends house in the middle of nowhere and the only place to get parts was a small hardware store that only had metal covers. :roll:
I didn't argue because I thought he was right.
Later I saw an argument here that an install like that wasn't "likely to be energized" and was legal but I don't know what came of that.
I'd look it up myself but my code book is waaaay over there........
Mine's quite near:grin:
I got cited by an inspector for the first time for doing this exact thing.
It was a friends house in the middle of nowhere and the only place to get parts was a small hardware store that only had metal covers. :roll:
I didn't argue because I thought he was right.
Later I saw an argument here that an install like that wasn't "likely to be energized" and was legal but I don't know what came of that.
I'd look it up myself but my code book is waaaay over there........
This is covered by 314.25(A), which requires metal covers and plates be grounded per 250.110. Unlikely to be energized does not relinquish the requirement. Besides, the only metal cover on a box that is unlikely to be energized is one that is not part of a complete system.
kwired
Electron manager
- Location
- NE Nebraska
Sometimes, you have to be inventive:
I have done that before.
frenchelectrican
Senior Member
- Location
- Nord'est Wisconsin et Paris France
I just wonding why not use the " dummy " or blank yoke that will serve as bonding for metal cover on the plastique boxes ??
Merci,Marc
Merci,Marc
frankft2000
Senior Member
- Location
- Maine
The dummy ones I have seen are 100% plastic also.
A/A Fuel GTX
Senior Member
- Location
- WI & AZ
- Occupation
- Electrician
If a blank metallic cover on a plastic box is required to be bonded, why in the world would the NEC allow 250.86 Ex 2 to be legal? Seems like selective enforcement to me. If the conductors in the plastic J box are properly installed, there is no way the cover could become energized.
Alright, I'm a happy camper. Found my code snippet I read yesterday, 314.41. That section wasn't in context to my original post but was driving me crazy not being able to find it. Think the reasoning for it is to prevent electrolysis on dissimilar materials. Guessing on that one though. I've been guilty in the past of using a metal cover on a plastic box also. Won't happen again unless it is bonded.
Philip Barr
Member
- Location
- Minneola Florida
As we speak little Timmy is standing in a puddle next to that box the cover of which has been energized by the brazed conductor pressing againt the cover, just waiting, waiting for that differance in potential, poor little Timmy.
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