Building Service - Equipment Bonding Jumper

[bahogge]

If a 12.47kV/480-277V transformer serves a building via underground PVC conduits encased in ductbank, does an equipment bonding jumper need to be routed with the phase conductors from the service disconnect back to the transformer? This assumes the grounding electrode connection is made at the service disconnect. It appears the 2005 handbook shows that to be the case for a separately derived system, but other illustrations in section 230-services only show the grounded conductor (neutral) routed back to the transformer. Thanks for any insight to clear up my confusion or misinterpretation.

 

[EEJaime]

If you look at NEC 250-30(a)(1)&(2), you will see that the location of the Main Bonding Jumper and the Grounding Electrode conductor should be as close as possible. Every building is to have it's own Grunding Electrode, so in the Service Entrance Conductors you do not have an equipment grounding conductor. At your main you will bond the grounded conductor, (neutral) to the Grounding Electrode and establish your building ground.

 

[controlsdude]

I always thought that EC&M magazine went over bonding and grounding examples and explanations of NEC to the Nth degree. Giving plenty of explanations for every type of installation.

Look here

http://ecmweb.com/

 

[bahogge]

Thanks for the quick responses!