What is the largest dry type transformer allowed in a drop ceilng? I read it as 50 KVA, but I was sure there was a condition that allows a 75 KVA in a drop ceiling, but I can't find it. Thanks
450.13(B) is pretty specfic that a transformer not exceed 50 KVA is permitted to be installed above a drop ceiling. I don't know of any exception to this requirement.