maximum fixture weight/ 8-32's

[edlee120]

Is it written anywhere, and can someone tell me, the maximum allowable weight of a fixture hung from a steel octagon box with two 8-32 machine screws supporting the fixture bar or other fixture mount?
Figuring that the box fastening exceeds the rating of the fixture support.

Thanks............Ed

[edlee120]

Re: maximum fixture weight/ 8-32's

From RACO:

"Steel Octagon Boxes 4 Inch - Drawn Construction 1/2 Inch Conduit Knockouts 1-1/2`` Deep - 15.5 Cubic Inches

Four 1/2`` conduit knockouts (sides). Five 1/2`` conduit knockouts (bottom). No bracket. Octagon boxes can be used in the installation of ceiling or wall lighting fixtures or as a junction box. Not designed for ceiling fan support. 50 pound maximum recomended static load."

Answered my own question.

[jwelectric]

Re: maximum fixture weight/ 8-32's

314.27 Outlet Boxes.
(A) Boxes at Luminaire (Lighting Fixture) Outlets. Boxes used at luminaire (lighting fixture) or lampholder outlets shall be designed for the purpose. At every outlet used exclusively for lighting, the box shall be designed or installed so that a luminaire (lighting fixture) may be attached.

Exception: A wall-mounted luminaire (fixture) weighing not more than 3 kg (6 lb) shall be permitted to be supported on other boxes or plaster rings that are secured to other boxes, provided the luminaire (fixture) or its supporting yoke is secured to the box with no fewer than two No. 6 or larger screws.

(B) Maximum Luminaire (Fixture) Weight. Outlet boxes or fittings installed as required by 314.23 shall be permitted to support luminaires (lighting fixtures) weighing 23 kg (50 lb) or less. A luminaire (lighting fixture) that weighs more than 23 kg (50 lb) shall be supported independently of the outlet box unless the outlet box is listed for the weight to be supported.

(C) Floor Boxes. Boxes listed specifically for this application shall be used for receptacles located in the floor.
Exception: Where the authority having jurisdiction judges them free from likely exposure to physical damage, moisture, and dirt, boxes located in elevated floors of show windows and similar locations shall be permitted to be other than those listed for floor applications. Receptacles and covers shall be listed as an assembly for this type of location.

(D) Boxes at Ceiling-Suspended (Paddle) Fan Outlets. Outlet boxes or outlet box systems used as the sole support of a ceiling-suspended (paddle) fan shall be listed, shall be marked by their manufacturer as suitable for this purpose, and shall not support ceiling-suspended (paddle) fans that weigh more than 32 kg (70 lb). For outlet boxes or outlet box systems designed to support ceiling-suspended (paddle) fans that weigh more than 16 kg (35 lb), the required marking shall include the maximum weight to be supported.

Here is what the code has to say about boxes

[edlee120]

Re: maximum fixture weight/ 8-32's

Thanks Mike for the reply and code citation. I really appreciate it.......Ed