The transformer manufacturer can recommend the distance needed for proper ventilation. An ABB standard dry type requires 24" front and rear. Depending on the transformer terminations, common practive is to close couple the switch and transformer. This can also be done for the LV equipment as well.
VPI transformers predominately use some sort of varnish to impregnate the insulation of the transformer. Cast coil transformers have the high and low voltage coils vacuum casted in an epoxy in some sort of a mold. Cast resin transformers can be similiar to cast coil transformers, and also wet...
