Does the working space in Article 110.26 apply to transformers? Would a 480V panelboard across the isle from a 480 to 208 transformer require 4' between them? Also, do the working space requirements apply to the sides of the transformer? If not, how much space would required on the sides to run conduit in and pull wire (aren't transformers usually fed with a LB into to side?) I am laying out an electrical room, but I'm not an electrician, and I'm not sure how the connections to transformers are usually made.
Finally, can the transformer be backed right up aginst a wall, or does it need breathing room behind it?