34 Pa. Code § 39.358
When equipment or lines are to be disconnected from any source of electrical energy, for the protection of workmen, the operator shall first open the switches or circuit breakers designed for operation under load, and then the air brake disconnectors, when provided.
34 Pa. Code § 39.358
This section cited in 34 Pa. Code § 39.155 (relating to character of switches and disconnectors); 34 Pa. Code § 39.411 (relating to general provisions); 34 Pa. Code § 39.421 (relating to general provisions); 34 Pa. Code § 39.431 (relating to general provisions); 34 Pa. Code § 39.441 (relating to general provisions); 34 Pa. Code § 39.451 (relating to general provisions); 34 Pa. Code § 39.461 (relating to general requirements); 34 Pa. Code § 39.462 (relating to authorization for work); 34 Pa. Code § 39.471 (relating to general requirements); and 34 Pa. Code § 39.491 (relating to general requirements).