Excess temperature protection for electrical fuse - has bimetal temperature sensor with fibre optic signalling of fuse condition and location for triggering corrective action

摘要

A temperature sensing and protection system for fuses is arranged to signal excess temperature and fuse location. Activation of appropriate cooling means or ultimate disconnection of the circuit then ensures after a suitable time delay if normal conditions are not restored. The temperature of fuse (S1) in housing (SG) influences the position of bimetal sensor (B) carrying element (P) such that the light path in sender unit (E) travelling via fibre optic cables (L1, L2) to evaluation unit (VE) can be interrupted in gap (US) thus affecting photo-element (F) and triggering protective sequence. USE/ADVANTAGE - In heavy duty high current distribution systems. Ensures reliable fuse operation by limiting temperature rise. Several grouped fuses can be supervised by a single optical cable with remote indication and local visual identification of fuse affected. Electromagnetic or ultrasonic signal transmission is suitable as an alternative. Temperature sensitive optical device can be substituted for bimetal sensor.