Are the inspectors allowing 3" pancake boxes for mounting light fixtures? Remember the cu. in. fill for this size box is 4 cu. in.

Sure- and why not?

Indeed, they are often used for ceiling fans as well.

The only problem is wire fill... if the circuit continues on to another fixture, then wire fill is violated. There's only enough room (legally) for one set of wires.

Short answer NO
4 cu inches ( 65 cm cubed) allows for the end of a 14 / 2, no ground, nothing else.
Fixture canopys add space but, unless they are marked with the Cu. In. they should not be counted.
Almost anyplace that a pan box can be used an L shaped box, i.e. pan with a wiring compartment on one side, would do better.
I once asked an engineer at Raco why they kept making the 3" pans and he said, Because inspectors kept allowing them to pass inspection.
Alan--

reno you must be thinking he said 4" pancake like I did at first.

Use listed #18 lighting whips in 3/8" Flex.

Problem gone....

You will need to have a junction box within 6 feet for the listed whip.

Alternately, for lighting only you can use the tap rules to run your own #18 even longer.

Look at NEC 2005 table 240.5

[This message has been edited by Tesla (edited 06-09-2006).]

[This message has been edited by Tesla (edited 06-18-2006).]

Big B, I bet you're right. I'm not sure I've ever seen the smaller one!

I let people use them if there is only one 14-2 in the box.

Doesn't the fixture canopy add to the capacity?


If the luminaire had a flat base that effectively stopped the box fill at the face of the box I could see the concern but if this is a bell canopy there should be plenty of room, even for two sets of #12s.

410.10 makes no mention of using the canopy of a fixture as space for branch circuit conductors, only the fixture conductors and their connecting devices. The branch circuit conductors are poperly housed in the box. If it were a 4" pan box it would properly house a single 14/2 WG NM cable and the fixture wires could be housed in the canopy. A 3" pan box is quite clearly not suitable for 14/2 WG NM cable but most of us, like Ryan would accept it.

Typo's

[This message has been edited by George Little (edited 06-13-2006).]