Oilfilled transformer clearance from walls

[nikhilengr]

Please help me wih code clearance requirements for an oil filled padmount transformer loacted near a combustible wall. NESC, NEC and OSHA requirements in particular. Code references?

Thanks.

 

[peebee]

NEC standards for transformers are found in Article 450. NEC is available on-line for free viewing at the following link -- click NFPA 70, then at the bottom of the next page click "View the 2005 edition of this document".

http://www.nfpa.org/aboutthecodes/list_of_codes_and_standards.asp

NEC generally just says that physical separation is a potential means of dealing with the fire hazard, but does not dictate the distance of separation required. Apparently, that detail is to be provided by the insurer. Factory Mutual is one rather conservative insurer -- but at least they are also prolific publishers. FM requirements for physical separation with various transformer fills can be found at:

http://www.cooperpower.com/library/TheLine/pdf/May03/03021.pdf

Hope that helps....

 

[PSE]

Your local fire officials may also be able to help you determine what requirements are needed. There is potential variance based upon type of construction etc.

Regards,