In electric power, power lines obstruction: the portion of the distribution system that is delineated by the connection point to the transmission system and the primary side of all substation transformers [Section 4(s), Anti-Obstruction of Power Lines Act of 2019; Section 4(pp), DOE Department Circular No. DC2020-02-0002, The Implementing Rules and Regulations of Republic Act No. 11361, Otherwise Known as the “Anti-Obstruction of Power Lines Act”]
Note: Cf. Subtransmission Systems.