RonABC wrote:
Is there a specific electrical code that states how many wires can be
attached per screw when wiring outlet receptacles?

I've always heard that when wiring receptacles, one shouldn't attach
more than one wire to each screw. I haven't been able to locate
anything about that in the 2008 National Electrical Code. It may be in
there, but so far, I haven't been able to find it.

It may be a function of how the devices are designed rather than an NEC
ruling. If they were not designed and/or UL listed to have more than one
wire that in itself I believe would fall under some general NEC
guidelines. But not sure what section?



Part of why I am curious is that I notice that typical outlet
receptacles have two silver screws, two gold screws, and only one green
grounding screw. And that started me wondering, "Why aren't there two
green grounding screws?" For outlets that are in the middle of a
circuit, there are typically six wires in the outlet box -- two black,
two white, and two grounds. So, wouldn't it be easier if the receptacle
had 6 screws? -- two for the two black wires, two for the two white
wires, and two for the two ground wires?

Is it possible that the code allows two ground wires to be connected to
the one green grounding screw, but does not permit two wires per screw
for the white and black wires?

I am pretty sure you must wirenut the grounds. Using the special green
wirenuts with the feed hole makes this much easier.
As far as I know NEC does not require pigtails on the other wires but
some local codes do. Pigtails are better as a device failure is not as
likely to take out other devices down stream.

I prefer back feed type outlets which will take as many as 4 wires on
each side. Not as good as using pigtails but better and much easier
than wrapping wires around screws.

On occasion I will feed 2+ outlets or switches with a single wire. I
strip enough insulation off to wrap around a screw then continue the
same wire to the next outlet/switch.

Kevin