When a motor is switched off, its deceleration is determined exclusively by the machine’s heavy duty torque motor 1hp 56, ie natural deceleration. Starting devices and electronic converters allow to control the deceleration by means of a linear or S ramp, normally independent of the acceleration ramp. The ramp can be set so as to obtain a steady-state speed passage at an intermediate or zero speed, which is less than the natural deceleration time. The engine has to develop a sturdy torque that adds up to the machine’s rugged torque, superior to the natural deceleration time, the engine has to develop a lower engine torque than the machine’s tough torque.
The reversal of the direction of rotation can be conducted with the engine stopped after deceleration without electric braking, or with electric braking to achieve deceleration and rapid reversal. Modern converters generally guarantee thermal protection of the motors and their own protection. From current measurement, a microprocessor will calculate the motor temperature rise and emit an alarm or shut off signal in case of overheating.