A quench detection system for a fault current limiter (1), in particular, a high temperature superconductor fault current limiter, making use of a differential protection relay wherein in fault event the differential protection relay operates a triggering mechanism of a circuit breaker (2), thereby opening the electrical circuit and interrupting power supply to downstream components, and a method for quench detection wherein the magnitude of voltage drop during quench is converted to a current signal being proportional to the voltage and which is monitored by the differential protection relay.