If any transformer (480 delta-208/120V) located in location within the building and the secondary conductors (no exposed conductors) was ran underground let?s say for 100ft, do we still need to have an OCPD at the transformer? My understanding was since it was ran underground then it will consider to be outdoors and it only required at the stup-location within 10ft of the panelboard with MCB or OCPD. Any thoughts?
Thanks,
Thanks,