Grounding Question - Light Fixture


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Old 01-19-14, 06:26 AM
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Grounding Question - Light Fixture

I have a outdoor weatherproof box with a halogen light connected to it. Its mounted over an electrical box that is recessed into the soffit. It is not directly connected to it by a bracket or the mounting tabs, rather screwed into the sofit and the wries are run thru the knockout. I noticed a ground wire was run between the box behind it with a grounding clip to the screw in the weatherproof box.

When I check the fixture for continuity I can get ohm indication between the box behind it and the screws on the fixture. The screws being the ones that hold the lamp holder cover to the weatherproof box and also the screws on the lampholder.

However, just touching bare metal portion of the fixture I cant get the same reading.

Can anyone explain that for me? And about light fixture grounding in general?
 
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Old 01-19-14, 06:43 AM
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It is not directly connected to it by a bracket or the mounting tabs, rather screwed into the sofit and the wries are run thru the knockout.9
It needs to be mounted to the box. Why isn't it? Are the wires exposed? If so that is wrong. Correct mounting will probably correct the problem. Not a direct answer to your question but I can only guess why you are getting the reading
 
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Old 01-19-14, 12:32 PM
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Im getting a reading because as I said the fixture is connected to the box under it with a grounding wire.

There are no exposed wires, the box is directly over the other box and the wires come thru the center knockout into the other box. The 4" weatherproof box is larger than the 2x3 device box in the soffit.


This is the fixture in question (sans the weather proof box that comes with the kit):

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Old 01-19-14, 02:15 PM
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This is the fixture in question (sans the weather proof box that comes with the kit):
Can you show us a picture of that box?
 
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Old 01-19-14, 02:25 PM
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Youer familiar with these, its a standard flood light. Knockouts screw in, you can add sealant to the threads.

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This box is mounted over a small device box in a wood soffit, it sits flush with soffit. No exposed wiring, the 2x14g plus a ground come thru the knockout in the center.

I was concerned that having the one box under this one would break the accessible wiring rule but it is technically accessible maybe a little inconvienient to unscrew the construction screws that attaches it to the soffit by the ears you see in the photo.
 
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Old 01-19-14, 02:36 PM
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However, just touching bare metal portion of the fixture I cant get the same reading.

Can anyone explain that for me? And about light fixture grounding in general?
I suspect the surface of the aluminum weatherproof box has some sort of finish on it that affects the resistance value. I wouldn't worry about it, but I would possibly check the hot wire to ground and be sure you get 120 volts, the same as hot wire to neutral.
 
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Old 01-19-14, 03:00 PM
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How about the installation in general? The way its mounted over the other box... is that kosher?
 
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Old 01-19-14, 05:41 PM
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You do not need the surface mount box. The flush mount box will contain the splice.
 
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Old 01-19-14, 05:59 PM
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You do not need the surface mount box. The flush mount box will contain the splice.
You need the weatherproof surface mount box to mount that type of light. I have seen some that fit on gem or device box, but this is round. Plus it would not fit on the box recessed into the soffit anyhow.

The fixture wires are not long enough to get into the box in the soffit so I have pigtails leading into the weatherproof box where they attach to the fixture wire.


Does any of this sound like a code violation or safety hazard?
 
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Old 01-19-14, 06:39 PM
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I'd replace the recessed gem box with a 4" round old work box and install the light directly to that box.
 
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Old 01-20-14, 04:52 AM
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My question remains, does any of this sound like like a code violation?

I'd replace the recessed gem box with a 4" round old work box and install the light directly to that box.
Why would I go to all that trouble if the current installation is compliant?
 
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Old 01-20-14, 05:33 AM
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Why would I go to all that trouble if the current installation is compliant?
I would do it that way because like you I wouldn't be sure it was code compliant. I'd know that way was code compliant. I'd do it that way because it would look better. I'd do it because I wouldn't have a splice in the old box partly hidden by the new box. However your way is probably code compliant. To be truly honest in my own house I'd probably do neither. I'd just use the existing box and screw the light to the soffit covering the box but here I try to post what is best, what I would do at a customer's house.
 
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Old 01-20-14, 06:07 AM
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To be truly honest in my own house I'd probably do neither. I'd just use the existing box and screw the light to the soffit covering the box
I cant picture this, what do you mean?
 
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Old 01-20-14, 06:21 AM
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Not important because I am not suggesting you do it that way but I mean I'd screw the light directly to the soffit. The screws going in to the wood of the soffit and the base of the light positioned to cover the existing box that is flush with the soffit.

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Old 01-20-14, 08:35 AM
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Can you post a pic of the existing box without the surface mount box in place?
 
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Old 01-20-14, 09:14 AM
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Can you post a pic of the existing box without the surface mount box in place?
No. But I think Its easy to visualize. Its a 2x3x2" box. The surface mount weatherproof box is 4". There is no gap between the two.

Even if I wanted to, you cannot mount the bulb cover of the Flood Kit to a 2x2x3 box like you suggested or as Ray said he might try.

Not to confuse matters (and this may be irrelevant to my inquiry) There is also aluminum soffit material surrounding the light. The weatherproof box acts as an extension so the fixture will fit properly through the hole cut in the material.

Bottom line, I know there is a box accessibility rule in the NEC. Do you think this violates this rule?
 
 

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