In article , Al Tsiemers wrote:
I want to put in 2) 20A curcuits in my shop area. I would like to have them
both go to a string of twin duplex boxes, with the left-hand duplex
recepticle in all boxes on one curcuit, and the right-hand on the other
circuit.
My calculations show a 32 c.i. box is required for 12ga. wire.
Questions:
1) I assume the grounds for both circuits can/should be tied together,
correct? They are uninsulated, so I can't see how that could be avoided.

There's no particular reason why they need to be tied together, and if you use
non-metallic boxes, it's avoidable.

2) If the first box in line gets two GFCI outlets (one for each circuit),
does that change the calculation for box size? Does the yoke count of 2 for
each device change because of the depth of a GFCI receptacle?

I don't see anything in the Code that indicates that it does.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.