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#36876 04/16/04 07:23 PM
Joined: Apr 2002
Posts: 257
M
Member
Here is the situation:

We are to install light fixtures on a walking bridge. The engineer's design calls for a fixture that fits between the 1/2" square steel pickets on the handrail which are about 4" apart.

The designated fixture is designed mainly for concrete pours but the cut sheet says that it is suitable for all types of construction.

Working with the engineer, we designed a template and a clamp that would hold the fixture backbox firmly to the pickets. We also installed 1/2" IMC stubs from under the bridge up about 35" to the fixture. The fixture backbox has a 1/2" opening but it is not a threaded hub.

When the owner examined the fixture and reviewed our proposed mounting means he suggested another option.

Instead of using the template that we designed, he wants to have the trims custom made (larger) so that they will function as a clamp and hold the fixture in place.

The only problem is that when the trim is removed for relamping the IMC and it's locknuts will be the only thing supporting the fixture. In other words, the fixture will not be securely mounted during relamping.

I don't feel that this method of mounting should be allowed but I can't find a good "code" reason not to do it.

What do you guys think? Am I over reacting?

#36877 04/16/04 09:10 PM
Joined: Aug 2003
Posts: 1,374
R
Moderator
314.23(F)
Quote

(F) Raceway Supported Enclosures, with Devices, Luminaires (Fixtures), or Lampholders. An enclosure that contains a device(s) or supports a luminaire(s) [fixture(s)], lampholder, or other equipment and is supported by entering raceways shall not exceed 1650 cm3 (100 in.3) in size. It shall have threaded entries or have hubs identified for the purpose. It shall be supported by two or more conduits threaded wrenchtight into the enclosure or hubs. Each conduit shall be secured within 450 mm (18 in.) of the enclosure.

[This message has been edited by Ryan_J (edited 04-16-2004).]

Nevermind, probably doesn't apply, other than during the process of re-lamping.

[This message has been edited by Ryan_J (edited 04-16-2004).]


Ryan Jackson,
Salt Lake City
#36878 04/16/04 09:14 PM
Joined: Sep 2003
Posts: 650
W
Member
Take a look at 314.22(F)Exception No. 2
a) the conduit is securely fastened (buried in concrete)
b)how long are the stubs _inside_ the concrete? They need to be 12" long
c) are these accessible to unqualified persons? This issue is _only_ during re-lamping; the fixtures are supported when the trim is on
d) these are less than 4" wide; how tall?
e) how heavy are the fixtures?
f) is there a suitable fitting that makes the connection properly wrench-tight?

-Jon

#36879 04/17/04 09:48 PM
Joined: Apr 2002
Posts: 257
M
Member
The conduit comes from under the bridge and is secured to the bridge with one minerallac clamp. The stubs are not in concrete at all.

Fixture is 9.3 inches tall by 3 inches wide by 3.9 inches deep.

Fixtures are 1 or 2 lbs.

The threads of the IMC go through a 1/2" hole in the bottom of the fixture with a locknut inside and outside of the fixture.

The fixtures will be supported when the trims are on.

#36880 04/18/04 07:51 PM
Joined: Jun 2001
Posts: 642
N
Member
Can you get the same fixture with a threaded entry hole?
Iwould personally not trust only mechanical support of a trim only to hold up to the elements of weather and possible pedestran abuse.
JMHO


ed

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