(5) For grounded systems, the grounded service conductor within the service equipment enclosure. So if your area has adopted NEC 2014, you can connect a grounding conductor to the grounding conductor from another branch circuit, as long as both circuits originate from the same panel.

NO ! You can’t share the neutral on the output of the GFCI. It must only go to the outlets being protected. If you try to share this neutral your GFCI will not work and will trip immediately.

No. By definition a neutral wire is a wire that is grounded to 0V. It does carry the current from the circuit back to the transformer however. If a system is wired correctly the neutral wire will never give you a shock.

If the individual ground wires were required that would be 3 20 or 15 amp circuits, but with a single ground wire or conduit as EGC you can get 4 circuits in there.

1. You can share a single ground but it must be sized for the largest circuit running in the conduit. 2. Yes it is ok.

For example, the smallest 2 x 4 x 1 1/2-inch deep box can comfortably splice only two cables (four or five conducting wires), while the largest 4 x 4 x 2 1/8-inch-deep boxes can handle as many as four to six cables (up to 18 individual conducting wires).

Electrical codes generally require that all electrical devices, and the wiring connections to those devices, must be enclosed in an approved electrical box. Often known as a junction box, this metal or plastic box includes a cover to protect the wiring within and protect you from the wiring.

To figure out what capacity of box you need you will need to make a calculation based on the number of conductors, switches, receptacles and any clamps that will be in the junction box. We will use 4 each 12/2 cables entering the box plus two receptacles for the calculation.

Subsequently, question is, how many 12 gauge wires can be connected together? The limit by code is 12 outlets per circuit. Choose the proper wing nut. The blue has a minimum of 3 #12 wires.

Since the conductors are without splice or termination, only six conductors are counted. Table 314.16(A) permits a maximum of nine 12 AWG conductors in a 4-inch square box that is 1 1/2 inches deep. This installation is Code compliant. (See Figure 3.)

Yes you can…. When I splice #10, I twist them together first with my lineman pliers before I put the wire nuts on. Use the red wire nuts (#6’s). I also use a propane torch and solder & tape a lot of splices…..