摘要 |
Disclosed herewith is a thermally-sensible overcurrent protective relay, which comprises normally-closed contact means, operation means, a plurality of bimetals, a communicating plate, a heater mounted on each bimetal and electrically coupled to at least one of main circuit terminals for a power-source side and a load side, a bimetal retainer electrically coupled to the other main circuit terminal, a first groove, a second groove and a heater holder having a pin fitted in a through hole formed in the bimetal retainer. The operation means opens or closes the normally-closed contact means. The same current as flows through a main circuit to be controlled flows through the bimetals. The communicating plate transmits mechanical deforming force of the bimetals to the operation means so as to open the normally-closed contact means. The heater, when generating heat, causes a mechanical deformation on the bimetals. The bimetal retainer secures one end of each bimetal. The first groove securely holds the main circuit terminals, while the second groove securely holds a connecting section between the bimetal retainer and the bimetals.
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