Feeder Taps Rules

[electrodog]

I would like some information on Transformer Feeder tap rules above and beyond what i have found in the nec 240.21 (B)(4). Concerning the horizontal length rule. Can this rule be used in commerical buildings or is it limted to manufacturing building only?

 

[davidbeach]

240.21(B)(4) does not apply to transformer circuits, and per the text of the paragraph is limited to manufacturing buildings over 35 feet high at the walls. Taps that include transformers are covered by 240.21(C).