Transformer above the ceiling

[olc]

30KVA dry type transformer (480 X 120/208)
Can it be located above a suspended accessible ceiling (say in a medical office building)?
Can it be located above this ceiling if the ceiling space is a return air plenum?

 

[mcclary's electrical]

30KVA dry type transformer (480 X 120/208)
Can it be located above a suspended accessible ceiling (say in a medical office building)?
Can it be located above this ceiling if the ceiling space is a return air plenum?

As long as less that 50 kva and you comply with 300.22 (c)(2) I think it is legal, but I need to double check that

 

[infinity]

30 KVA should be fine.

All transformers and transformer vaults shall be readily accessible to qualified personnel for inspection and maintenance or shall meet the requirements of 450.13(A) or 450.13(B).
(A) Open Installations. Dry-type transformers 600 volts, nominal, or less, located in the open on walls, columns, or structures, shall not be required to be readily accessible.
(B) Hollow Space Installations. Dry-type transformers 600 volts, nominal, or less and not exceeding 50 kVA shall be permitted in hollow spaces of buildings not permanently closed in by structure, provided they meet the ventilation requirements of 450.9 and separation from combustible materials requirements of 450.21(A). Transformers so installed shall not be required to be readily accessible