Torque switch
A Torque switch is similar to a limit switch in that it is used to trigger when there is too much torque. Such as, when the valve has fully opened and pushing against the wall, the torque switch will tell the motor to stop.
The torque switching is not only used for torque seating in the end position, but it also serves as overload protection over the whole travel and protects the valve against excessive torque. If excessive torque acts upon the closing element in an intermediate position, e.g. due to a trapped object, the torque switching will trip when reaching the set tripping torque. In this situation the end position is not signalled by the limit switch. The controls can therefore distinguish between normal operation torque switch tripping in one of the end positions and switching off in an intermediate position due to excessive torque.
See also