Soft start is equivalent to the hot start of the microcomputer, re closing all the programs, releasing the memory occupied by the program, the data data and the software installed by the individual are not affected. And hard start is to restore to the factory settings, clear all the data data, personal installation software. Hard start must be backed up in advance, otherwise everything will have to be back.
(1) overload protection function: soft starter introduces the current control loop, so it can track and detect the current change of the motor at any time. By adding overload current setting and inverse time limit control mode, the overload protection function is realized. When the motor is overloaded, the thyristor is switched off and the alarm signal is sent out.
(2) lack of phase protection function: when working, the soft starter detects the change of the three phase current at any time. Once the disconnection occurs, the phase protection reaction can be made.
(3) overheating protection function: the temperature of the thyristor radiator is detected by the internal thermal relay of the soft starter. Once the radiator temperature exceeds the allowable value, the thyristor is turned off automatically, and the alarm signal is sent out.
(4) phase function: through the internal short-circuit protector can be made in the protection of thyristor phase breakdown is. Can not start, avoid the thyristor fault after the start caused by other components over-current damage, and other equipment overcurrent tripping, affect the production.
(5) other functions: through the combination of electronic circuits, but also in the system to achieve other kinds of interlocking protection.
Development history
Soft starter in the late 1970s and early 80s into the market, to fill the gap between the star delta starter and inverter in the functional utility and price gap. The soft starter can control the voltage of motor, which increased gradually in the process of starting, naturally control starting current, which means that the motor can be started smoothly, mechanical and electrical stress to a minimum. Therefore, soft starter is widely used in the market, and the soft stop function of soft starter can effectively avoid the "water hammer effect" when the pump stops".
