Overvoltage limiter with fault indicator visible through window - causes green aspect to be superseded by red aspect consequent on movement of strip displaced by rupture of fusible element

摘要

The overvoltage limiter has a varistor (14) and a fusible element (15) connected in series between two connection terminals (13A,13B) in a housing (19). Rupture of the fusible element causes a strip or band (18) to move from its normal position into a fault-indicating position. The free upper end of the strip has a green portion (40S) which normally is visible through a small window (17) in the top of the housing. A fault is indicated by movement of a red portion (40D) of the strip into alignment with the window. ADVANTAGE - Esp. simple and compact structure has no component projecting from its housing in either normal or fault conditions.