What minimum size copper equipment grounding conductor is required to be run in a PVC pipe for a new feeder protected by a breaker rated at 150 amperes?

The minimum size copper equipment grounding conductor that must be run in a PVC pipe for a new feeder protected by a 150-ampere breaker is determined by the National Electrical Code (NEC) requirements for grounding conductors. According to NEC guidelines, the size of the equipment grounding conductor is based on the size of the overcurrent protection device (the breaker in this case) and the characteristics of the wiring system.

For a feeder protected by a 150-ampere breaker, the NEC specifies a minimum size of #6 AWG copper for the equipment grounding conductor. This size is acceptable as it provides adequate capacity for fault current return to effectively trip the breaker under short circuit or ground fault conditions.

Other conductor sizes listed do not meet the minimum requirements set forth by the NEC: #4 AWG is larger than necessary, while #8 AWG and #10 AWG do not meet the minimum size requirement for a 150-ampere service. Thus, #6 AWG is the correct choice for ensuring safety and compliance with electrical codes.