FD Fixtures

[mobiledynamics]

OT, but what is the history on FD *boxes/outlets* - meaning why/what is the purpose of this device mounting format versus let's say a normal single or 2 gan mounting device lineup.

Most of the industrial stuff like Appleton, OZ, etc - or just other stuff like Marine receptacles, all sort to follow the *FD* box lineup.

 

[PRH44]

You will find this same bolt pattern in bell boxes cast and malleable and other styles as well. There are some devices/covers that cannot bolt to the center holes and require a 4 corner style of attachment most are of the weather proof type or large devices.
http://www.cooperindustries.com/content/dam/public/wiringdevices/BuyersGuides/AHBG/M/AHBG-M-Sec.pdf look on page 3 for and example.

 

[mobiledynamics]

Hi PRH -

The bolt pattern of the iron boxes and some of the rubberish marine boxes. The SHAPE of the rectangle/square box device appears to be a different size - I don't think it would match up to the bell box but I may be wrong and the the size is the same, just the hole arrangement is different.