How do the motor over temperature switches shut down the motors in the F680e?

All F680e sprayers have an electric motor that drives the hydraulic pump.  Systems that include an integrated air compressor have a second electric motor that drives the compressor.  Each motor has a normally-closed over temperature switch inside the motor.  The electrical control box contains a start and stop switch that controls a low-power 230VAC contactor coil for each motor.  

The over temperature switch for each motor is wired in series with the contactor coil, between the red stop switch (orange wire of motor harness) and contactor coil terminal A2 (red wire of motor harness).  When the over temperature switch opens, the current path to the contactor coil is broken, which causes the contactor to open and stop the motor.  Each motor is independent, so only the motor with the tripped over temperature switch will shut down.  The over temperature switch is automatically-resetting, so the motor can be restarted after it has sufficiently cooled by pressing the green motor start button on the electrical control box.