If busduct is being run as the service entrance conductors on a 480V 3P/3W system (No L-N loads served from service entrance switchgear) does the busduct need to be a 3W busduct with the (3) phases and an integral ground or does it have a be a 4W busduct with the dedicated neutral bus. For service entrance neutral with no L-N loads the neural conductor only needs to comply with 250.24(C) but I'm not sure how this relates to busduct and the physical construction? Would the ground bus integral to busduct comply with 250.24(C) or do you need a dedicated neutral bus?