410.20 - space for conductors - using canopies with pancake box

[dana1028]

Can multiple NM cables enter a standard pancake box [4.5 cu. in.] using 410.20 if you use the space in the luminaire canopy to accommodate the vol. fill? It appears to allow this. If so, are there any special requirements with respect to the luminaire [canopy]?

I've been told you can't do this - i.e. over fill of pancake, and then I've been told this is allowed.

thank you

 

[Dennis Alwon]

It is allowed if the canopy is marked with a cu. in so you can calculate how many wires will be appropriate. As a rule I have not seen many canopies that were marked with the volume. I generally will only install one 14/2 cable in it

 

[infinity]

For a 4.5 CU in box I would install one 12/2 or 14/2 AC cable.