Disconnect switches establish isolation points to enable equipment maintenance. They are installed on both sides of the circuit breaker, high-side of the transformer, and on the line exit. Switches cannot and should not be used to interrupt load current or fault current. A switch operation takes place after the circuit is de-energized.
Power substations contain transformers, breakers, switches, and plenty other critical pieces. Articles under this category explains the equipment design in detail.
With the advent of modern microprocessor relaying, much of the communication between relays has been shifting from power-line-carrier apparatus or microwave to fiber. Since power utilities own the easements for the high voltage transmission lines, it is only logical to install fiber up there. One ingenious location is the lightning shield wire. It is the …