Overcurrent Protection, Tamper-Resistant Receptacles and More

摘要

I installed a service that consists of one 200-ampere disconnect and three 100-ampere disconnects in separate enclosures. A wireway, which contains service-entrance conductors, supplies these disconnects. I used a grounding electrode with taps from each 100-arnpere disconnect. The service consists of three 3 AWG Type THWN copper conductors for the 100 ampere disconnects and one set of 3/0 AWG Type THWN copper conductors for the 200-ampere disconnect. What size grounding-electrode conductor is required? There are numerous ways to ground this service. A single grounding-electrode conductor may be connected to the grounded service conductor in the wire-way. The size of this grounding-electrode conductor is obtained by taking the sum of the service-entrance conductors and using this total circular mil area to size the grounding-electrode conductor to be connected to the buried metal water pipe.