Definition of film cutout
a thin insulating film that breaks down when a series filament street lamp fails and that short-circuits the lamp so as not to interrupt the service elsewhere

При срабатывании выскакивает страйкер и нажимает триггер расцепителя, который цепь размыкает.

In electrical distribution, a fuse cutout or cut-out fuse is a combination of a fuse and a switch, used in primary overhead feeder lines and taps to protect distribution transformers from current surges and overloads. An overcurrent caused by a fault in the transformer or customer circuit will cause the fuse to melt, disconnecting the transformer from the line.

Возможно я неправ.