| 摘要 |
PROBLEM TO BE SOLVED: To easily predict that a relay is close to its life end point.SOLUTION: A relay 1 comprises: a power line 10 having fixed contact points 15a and 15b; a driving member 13 for actuating a movable contact point 14 for performing connection or disconnection between the fixed contact points 15a and 15b; a temperature sensor 21 for detecting air temperature of a place affected by heat generated from contact parts between the fixed contact points 15a and 15b and the movable contact point 14; an outside temperature sensor 20 for detecting outside temperature; and an operational circuit 23 for outputting a signal showing that the relay is close to its life end point when difference between a detection value by the temperature sensor 21 and a reference temperature value obtained by adding a temperature rise value based on a heat value calculated using a current value of current flowing in the power line 10 to outside temperature detected by the outside temperature sensor 20 is equal to or larger than a preset value. |
