AboutJeremy Adams Expertise I can answer basically any question pertaining to the field of electricity, its applications and daily uses, theory, calculations, how to for residential, commercial, and light industrial. I am an inside wireman, therefore I can't help much with questions to do with linework, such as powerlines and distribution switchyards. I can however, answer some questions that have to do with power generation.
Experience I have 15 years in the trade and currently I am employed at TVA Cumberland City Fossil Plant where we generate about 10% of the power used in the Southeast. Of those 15 years, I have wired houses, wired many office complexes, banks, hospitals, schools, industrial applications, and can also install fire alarm systems.
Organizations IBEW Local 429 Member
Education/Credentials 4 yrs Calhoun Occupational Trade Center
Expert: Jeremy Adams Date: 7/10/2008 Subject: two services common neutral
Question I have been presented the following:
An industrial complex having many buildings each with its own pad-mount xfmr (12.47kV - 480/277V). The primary is fed from the owners MV distribution loop, not the utility. There is a generator supplying E-power to two separate buildings. This E-system utilizes 3-pole solid neutral ATS's in each building. The generator neutral is not bonded. The neutral at each service xfmr is bonded. Is this a violation of Art 250, or would 250.24(3)"Dual-Fed Services" cover this installation?
Answer Jim,
I do not think so, but code interpretations can go both ways sometimes. It would be in your best interest to call your local planning/building department and have an inspector come out. He will be more than happy to do so and since ultimately "he" is the governing body he can give you the final say on this matter.
