For a 30 amp branch circuit for field installed skeleton neon tubing installed using PVC conduit, what is the minimum size copper equipment grounding conductor required for grounding metal parts?

• A. 8 AWG
• B. 10 AWG
• C. 12 AWG
• D. 14 AWG

Answer: (B)

Grounding conductors are sized based on the overcurrent device protecting the circuit, so they provide a low-impedance path for fault current to trip the breaker. For a 30-amp branch circuit, the NEC table for equipment grounding conductor sizing requires a 10 AWG copper conductor.

In this setup, the skeleton neon tubing is installed in PVC conduit, which does not provide a grounding path by itself, so you must run a separate copper equipment grounding conductor with the circuit to ground the metal parts. The metal parts must be bonded to this conductor so that a fault current has a proper path to trip the breaker quickly.

The other sizes aren’t correct: 8 AWG is larger than necessary; 12 AWG and 14 AWG are too small for a 30-amp circuit and wouldn’t meet the required grounding conductor size. Hence, the minimum required is 10 AWG copper.