초록 ▼

The protection relay comprises a processing unit and temperature sensors associated to conductors, an ambient temperature sensor, and setting devices connected to circuits which perform tripping functions. A first short delay tripping circuit supplies a tripping order to a relay if a value of the te

The protection relay comprises a processing unit and temperature sensors associated to conductors, an ambient temperature sensor, and setting devices connected to circuits which perform tripping functions. A first short delay tripping circuit supplies a tripping order to a relay if a value of the temperature variation of a conductor exceeds a first setting threshold. A second long delay tripping circuit supplies a tripping order to the relay if a value of the temperature difference between the temperature of a conductor and the ambient temperature exceeds a second setting threshold. The protection relay is used notably for trip devices and circuit breakers.

대표청구항 ▼

[ We claim:] [1.] A protection relay for protecting at least one electrical conductor, which relay comprises a processing unit, said processing unit comprising:first means for thermal protection comprising means for detecting a temperature variation in a conductor to be protected connected to a firs

[ We claim:] [1.] A protection relay for protecting at least one electrical conductor, which relay comprises a processing unit, said processing unit comprising:first means for thermal protection comprising means for detecting a temperature variation in a conductor to be protected connected to a first comparator;first means for setting and supplying a first threshold signal to said first comparator;first means for measuring a temperature of the conductor to be protected and for supplying a signal representative of the temperature of said conductor to said means for detecting a temperature variation, said first means for measuring a temperature being in thermal contact with said conductor to be protected; andsaid first means for protection supplying a tripping signal to a contact when a value representative of the variation of the temperature of the conductor to be protected exceeds a value representative of said first threshold signal.