Mike Dolt Enterprises
Mike Dolt Enterprises
User: d-decherd, Location: Illinois
Asked on: Thursday, April 21, 2011 at 9:13 am EDT
Answered on: Tuesday, May 14, 2024 at 4:28 am EDT
Question: We are looking at revising the wiring to an existing stadium lighting system.All of the lighting poles are fed underground in conduit.A typical lighting circuit has a 30 amp, 3 pole, 3 phase circuit breaker feeding a single pole.There are four poles fed from one panelboard.Each pole has its own 3 pole circuit breaker feeding the lights on the top of the pole.There is one grounding conductor going from the panelboard to all of the poles.The grounding conductor is tapped at each pole.The wirenuts that are used to tap the grounding conductor are installed underground. These will have to be replaced.Question:Is there a provision in the code that requires that you bring a separate grounding conductor to each pole.Example: Are you required to run a single grounding conductor with each 3 phase circuit?
National Electrical Code (NEC) Article 250.122 requires that a grounding electrode conductor (GEC) be installed in each raceway to the building or structure (i.e., the stadium). Article 250.122(C)(2) allows the GEC to be tapped from an equipment grounding conductor (EGC) in a raceway.Therefore, the NEC does not require a separate grounding conductor to be run to each pole. The grounding conductor can be tapped from the EGC in the raceway leading to the pole.
However, there are some considerations to keep in mind
The EGC must be sized according to
Article 250.122(C). The wirenuts used to tap the grounding conductor must be listed for underground use.* The splice should be accessible for inspection and maintenance. Flag for review