series of neutral conductor

parallel of neutral conductor

series of live conductor

parallel of live conductor

neutral cable

phase cable

earth wire

any wire/cable

open circuit

over load

short circuit and overload

open circuit and overload

To protect the operator

To protect the line

To prevent excessive current

To open the circuit

voltage caused by a short circuit

current flow caused by a short circuit

voltage caused by an open circuit

current flow caused by an open circuit