Hello -
I have a grounding / code question and would appreciate any comments or opinions.
from NEC 250.146(A)
Surface Mounted Box:
A listed exposed work cover shall be permitted to be the grounding and bonding means when
(1) the device is attached to the cover with at least two fasteners that are permanent (such as a rivet) or have a thread locking or screw locking means and (2) when the cover mounting holes are located on a flat non-raised portion of the cover.
OK- To me, a rivet doesn't seem like an effective means of grounding and I would never rely on it...
I use surface mounted boxes, attached to panel with rigid box spacer (Raco 141 or 142), using non-concentric holes. The box is effectively and solidly grounded to the panel enclosure (this is not the issue). And the covers are to the box mounted using the non-raised area of the cover.
The receptacles are mounted to the cover using "whizzer" or "keps" type locking nuts.
To me this seems like an effective ground. I would be hesitant to use this method if we were talking about a conduit run where compression or screw type fittings were part of the grounding means -then I would run a ground wire. Where the box is attached with rigid conduit or fittings, I don't think a ground wire would serve to improve the integrity of the ground.
My question:
Do the whizzer or keps nuts satisfy the code requirement "thread locking or screw locking means"?
And: Would you consider the device as effectively grounded if it were in your own home?
THanks! DX
I have a grounding / code question and would appreciate any comments or opinions.
from NEC 250.146(A)
Surface Mounted Box:
A listed exposed work cover shall be permitted to be the grounding and bonding means when
(1) the device is attached to the cover with at least two fasteners that are permanent (such as a rivet) or have a thread locking or screw locking means and (2) when the cover mounting holes are located on a flat non-raised portion of the cover.
OK- To me, a rivet doesn't seem like an effective means of grounding and I would never rely on it...
I use surface mounted boxes, attached to panel with rigid box spacer (Raco 141 or 142), using non-concentric holes. The box is effectively and solidly grounded to the panel enclosure (this is not the issue). And the covers are to the box mounted using the non-raised area of the cover.
The receptacles are mounted to the cover using "whizzer" or "keps" type locking nuts.
To me this seems like an effective ground. I would be hesitant to use this method if we were talking about a conduit run where compression or screw type fittings were part of the grounding means -then I would run a ground wire. Where the box is attached with rigid conduit or fittings, I don't think a ground wire would serve to improve the integrity of the ground.
My question:
Do the whizzer or keps nuts satisfy the code requirement "thread locking or screw locking means"?
And: Would you consider the device as effectively grounded if it were in your own home?
THanks! DX
