isn't there a limitation to size of transformer above ceiling I thought I have read before you can't put more than 50 kva transformer above ceiling but looking in transformer section I could not find any information
Is this what you are looking for? (B)
450.13 Accessibility. 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).
Transformers are not accessible if wiring methods or other equipment obstruct the access of a worker or prevent removal of the covers for inspection or maintenance. Practical clearance considerations required for removal and replacement of the transformer are also important.
(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.
