What is the isolator? All Questions › Category: Switchgear And Protection › What is the isolator? 0 Vote Up Vote Down CS Electrical And Electronics Staff asked 4 years ago I need short information. 1 Answers 0 Vote Up Vote Down Best Answer CS Electrical And Electronics Staff answered 4 years ago The isolator is a device like a switch which is used in the substation to interrupt the circuit or to break the circuit.