110.58 only applies to only applies to installations in tunnels. Is this office building being built in a tunnel (kind of like some of those underground storage facilities)? If not, then you don't need a disconnect in sight from the transformer. If you did, you would be limited to a maximum of 50 feet to the disconnect (definition in Article 100).
Look at the definition of a lighting and appliance panelboard in 408.34(A). If the panelboard you're installing meets this definition, then you must provide protection for it.
Also, don't forget that you need to protect the conductors from the transformer to the panelboard (article 250).
You can do your grounding & bonding at the transformer or the panelboard, your choice. If done at the transformer, you would not install the bond screw at the panel. Most of the installations I've seen or done, the grounding & bonding is at the transformer.
Last edited by Tom; 04/06/07 12:18 PM.
