On Sat, 13 Oct 2018 12:36:57 -0400, "Mr. Luddite"
wrote:

On 10/13/2018 12:18 PM, wrote:
On Sat, 13 Oct 2018 05:31:57 -0400, "Mr. Luddite"



Ah, I think you are referring to industrial code requirements. Not sure
they all apply to residential wiring in a house but again, I am not
an electrician and don't even have a current code book. :-)

Nope 210.21(B)(2) applies to everyone
(2) Total Cord-and-Plug-Connected Load. Where connected
to a branch circuit supplying two or more receptacles
or outlets, a receptacle shall not supply a total cord and-
plug-connected load in excess of the maximum
specified in Table 210.21(B)(2)
http://gfretwell.com/electrical/Tabl...21%20B%202.jpg



Pardon my ignorance but doesn't "cord and plug" mean
an extension cord or the cord connected to the device
you plug into the receptacle (like a toaster)? If so, it sorta makes
sense. Tip off is that the 12 amps applies to both
15 amp and 20 amp branch circuits.

If I understand it correctly, a single, dedicated 20 amp outlet
with breaker and wire size (12 ga) can power a
plugged in device that draws up to 20 amps but
if that 20 amp branch circuit has two 20 amp outlets or more
you are not suppose to plug in anything that draws more than 12 amps.

That is the maximum allowed per piece of equipment. If you have a
dedicated 20a circuit that piece of equipment will be max 16a.

If this is correct (probably isn't) who the hell enforces this?

It is enforced by 240.4(D) that mandates the 14ga=15a, 12ga=20a by the
allowable breaker size. If you plug in too much, you trip the breaker.

If you ran the Neher McGrath formula you would find 14 ga wire really
handles 20a and 12 ga handles 25a (310.16 used to say that but they
changed it because Canada did)
240.4(D) was put there too ensure you still had your 80% safety margin
when you turned the user loose.
http://gfretwell.com/electrical/Nehe...%20formula.jpg

They still enforce an additional 80% factor on each piece of
equipment, making 15=12