High output for water boiler - has protection for switching surges and directly heated bimetallic element in multiway switching circuit

摘要

The high capacity electrically-heated hot water boiler has a temp. control system using a directly-heated bimetallic element. The switching element prevents a high starting surge when the mains voltage returns. The bimetallic element (12) operates in conjunction with a changeover contact (13). In one setting of the changeover switch the current passes through a heating element (11) which heats up the bimetallic element. The second setting of the changover switch cuts out the current flow through the heating element for the bimetallic strip and through the safety circuit (7). The current which flows through the safety circuit is supplied through the neutral line.