An important change in the 2006 Michigan Electric Code (MEC), which takes effect November 23^d, is found in Article 250.50 of the 2005 National Electric Code (NEC^®) NFPA 70-2005. The 2002 version of the NEC^® stated “Where available on the premises at each building or structure served, electrodes specified … shall be bonded together to form the grounding electrode system. …” In the 2005 version this Article reads “All electrodes specified … that are present … shall be bonded together to form the grounding electrode system. …” The specified electrodes include concrete encased electrodes (CEE) which are defined as an electrode (not less than ½” diameter reinforcing bar or bare copper conductor not smaller than 4 AWG) encased by at least 2 inches of concrete, located within and near the bottom of a concrete foundation or footing that is in direct contact with the earth … . This will require close coordination between the concrete and electrical sub-contractors to prevent costly rework later.

The MEC applies to multi-family and non-residential structures.

This change will also be in the 2006 Michigan Residential Code (MRC) whenever it becomes effective (March 2008?).

The full text of the 2005 NEC can be reviewed by visiting the NFPA web site.

Select NFPA 70, then 2005 NEC^®.