Thermal protections

K (klixon) : a device that warms up with the current flowing through it, the heat activates a switch that opens the circuit. If when starting the motors is blocked, its current will be over nominal and the switch will disconnect the motor, you need to push the red botton to restart the motor.
(see device), (see mounted on motor), (see connection)

ThB : a bimetallic switch that is placed between the very windings of the motor. The switch opens when the temperature is to high.(currently available 100-120-135-150C). (see picture)(Conn. schema)
This device can be placed directly in series with the motor but then the motor current heats also the device (only small motors). Note that the motor will restart automatically when cooling (danger !).