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Posted By: patrick1 Existing wire ratings with 90C Fixtures - 01/14/07 04:08 PM
Very often Listed installations are overlooked, in my humble opinion, when remodeling makeovers of Dwellings are performed. I understand that the connection of an incandescent light fixtures or any other luminaire rated for 90 Degree celscius wire connections should not be an acceptable install if the existing wire used is not rated for the connection to that Fixture's Listed Wire connections. This is a very real fire hazard, as I see it, when existing wire at ceiling boxes is cloth covered insulation and also tw is only rated for 60 degrees Celscious. Anyone?
Patrick- You are quite right in your call. This often gets overlooked by the inspector because he does not witness that connection. There is an easy fix for this by the installer if he has access to the junction box from the attic. Install a short length of 90° wire (maybe 3 feet) from a newly installed j-box to the existing box and splice the lower temperature wire to it and then splice the high temp wire to the fixture in the existing fixture opening box. If you don't have access to the existing box from the ceiling, your up the proverbial creek.
Posted By: Roger Re: Existing wire ratings with 90C Fixtures - 01/14/07 06:16 PM
It seems to me that this is just the manufacturers CYA.

I have seen the 90 deg requirement on chandeliers where the lamps are 18" or more from the supply conductors, I would think this is more than a sufficient heat sink before the heat could affect the conductors.

In renovating my own house (circa 1939) I left some of the old fixtures as well as installed some antique fixtures that I have rewired and connected to the old wiring and none of these have 90 deg requirements.

I don't know of any prohibition to using old or antique fixtures.

With all that said, I do see this as an issue that an inspector would have to cite if the fixtures instructions included the information/instructions in there listing and labeling [Linked Image]

Roger
Posted By: iwire Re: Existing wire ratings with 90C Fixtures - 01/14/07 06:42 PM
I also see it as Roger does. It is an enforceable issue, but it may be a bit over the top.

Is it really safer to basically force leaving an old fixture with no insulation instead of allowing a new fixture with its insulation and likely lower wattage lamps?

And as far as a pendant type fixture that is just ridiculous.
Posted By: patrick1 Re: Existing wire ratings with 90C Fixtures - 01/14/07 10:38 PM
Older fixtures dont carry a Listed tempurature rating, so I think technically, if the old wires are still in order and have not been subject to overloading over the years that making the connection is okay. If your hanging a chandelier of course, there is plenty of room to disapate further damage from heat. The problem I still have is the new fixture or chandelier probably still carries a 75C or 90C temp. rating and therefore not approvable. The contractor that makes that connection is more than likely the responsible party in the event of electrical failure.

The reason I Put this question out there is so many times this connection of new fixtures to old wires is what is asked of contractors by dwelling owners with the foremost issue for the owners is not incurring further costs on the project.

To me customers requiring connection to old wires requires an explanation of the Codes, a proper quote for necessary rewiring with the fixture changes, and walk.
Posted By: Roger Re: Existing wire ratings with 90C Fixtures - 01/14/07 10:54 PM
Patrick, I agree with you and the article would be 110.3(B)

Roger
I agree with those who say this is just the luminaire manufacturer's lawyer talking. I suspect the real fear is not that the new fixture will damage the wire but that the wire is already cooked, the installer creates a dangerous situation during that install and the fixture manufacturer, being the deepest pocket, gets blamed.
I saw this warning in a swag chain kit.
Posted By: patrick1 Re: Existing wire ratings with 90C Fixtures - 01/15/07 12:10 PM
Hi Roger
Thank you for the accurate direction to 110.3.
It is what it is ladies and gentlemen. What ever the motivation is the fixture people have got their butt covered. Maybe it's the smaller canopies, maybe it's the smaller gauge fixture wires, maybe it's the fixture people wanting us to connect to a good high temperature wire or maybe that's the way they were able to get their product listed. As an inspector or as an installer we can't take the Listing or Labeling lightly (no pun intended).
Posted By: mikesh Re: Existing wire ratings with 90C Fixtures - 01/15/07 05:23 PM
This is a real problem. I have seen even new wiring destroyed from the heat of a fixture. In older houses I regularily reject fixture installations where an old fixture is replaced. the problem usually exists where the new fixture is enclosed and mounts tight to the cieling. any fixture with a pendant or the older open bulb types with an open shade did not transfer much heat to the box wiring. Even compact flourescent fixtures have destroyed the boxes and wiring from too much heat.
the second problem arises where new fixtures are required to be bonded and the box does not contain a bonding conductor.
I have seen several work arounds and heard of others.

1. If you see this is a box on a bar hanger, remove the box, attach a second handy box to one side with a chase nipple or offset nipple. Move the NM to the new box. Make a splice to some NM-b or THHN in the second box and put a cover on it. Then you can shove the whole cludge up past the bar and reattach it. This is still "accessible" since you installed it without disturbing the finish.

2. Some kind of shrink tubing to bring the NM up to 90c standards YMMV on this with the AHJ.

3. Knock the old "nail on box" out, splice the NM to NM-b with an Enerflex device and install an old work (bar hanger) box. Or see #1 once the box is gone.
Posted By: Steve T Re: Existing wire ratings with 90C Fixtures - 01/28/07 07:00 PM
In chicago and burbs, there is very little NM. The boxes are all hard piped, this makes changes a little more difficult. Of course it makes it easier to repull new wires. But a homeowner isn't happy to hear they have to rewire part of the house to change out a light fixture.

Now the other question is, does the listing require the wires connected to the fixture wires to be 90C or all the wires in the J-box? When the J-box is part of the assembly of the fixture such as can lights, I can see it, but a j-box mounted in the ceiling? If it is just the connected wires, then add some new pigtails to the old wire.

If the old insulation is falling off the existing wires, then it is not really insulation anymore and must be replaced anyways.
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