I did an EE set for a Bank T.I. in Westchester (1 mile from LAX Airport), and the original building (shell) was to have a setup similar to this - which was to be performed during a previously done remodel and addition to the entire building.
These plans were dated 1976, and the pages I am referring to were designed per LADWP Design Engineer's requests.
Was to have a Delta - Delta 750 KVA Transformer on the Roof, fed from overhead 13,200 VAC Primary Feeders to a dead-end rack.
I guess they scrapped these plans, and put everything underground instead.
It was a real eye catcher! Had to look three times at the Plan Page to make sure it was showing this!
All the Buildings in this area have the same model# GTE / Sylvania Gear (Main Breaker in the Pull Section, 800 amp rated multi meter sections, Federal Circuit Breakers, 1Ø 3 Wire).
Roof mounted HVAC equipment carries the wild phase and ends the grounded conductor at the service equipment - also located on roof / 2nd floor.