1.) A grounding electrode conductor that is attached to the grounded conductor or equipment grounding terminal bar of a remote panelboard.
Note: This item has been part of the most common deficiencies since 1999. Although this is not found as often as it was prior to 1999, it still is an issue that is misunderstood and therefore bares consideration.
250.24(A) System Grounding Connections. A premises wiring system supplied by a grounded ac service shall have a grounding electrode conductor connected to the grounded service conductor, at each service, in accordance with 250.24(A)(1) through (A)(5).
(1) General. The connection shall be made at any accessible point from the load end of the service drop or service lateral to and including the terminal or bus to which the grounded service conductor is connected at the service disconnecting means."
Example: a single family dwelling that has an attached garage. There is a 200 ampere main disconnect located in the garage and a 4/0 aluminum SER Cable has been run to a panelboard located in the basement. A grounding electrode conductor has been attached to the metal water pipe feeding the dwelling and run to the panelboard located in the basement. The grounding electrode conductor has been terminated on the grounded conductor (neutral) terminal or equipment grounding bus of the panelboard. This panelboard, being a remote panelboard, has been supplied by a feeder and is not part of the service. Therefore, the grounding electrode conductor should have been run to the 200 ampere service disconnect in the garage.