Tag: soft starter

The VFD is generally not suitable for switching back and forth between devices such as output contactors, because its control is complicated. When the motor is switched, it may cause the motor to idle, and its phase is very different from that of the variable frequency drive output. There is a relatively large impact, which will affect the life of the IGBT of the inverter. The soft starter itself is designed with these in mind, using some phase-locked loop techniques to track. So when do you need a soft starter?

An induction motor is similar to a poly-phase transformer whose secondary is short circuited. Thus, at normal supply voltage, like in transformers, the initial current taken by the primary is very large for a short while. Unlike in DC motors, large current at starting is due to the absence of back emf. If an induction motor is directly switched on from the supply, it takes 5 to 7 times its full load current and develops a torque which is only 1.5 to 2.5 times the full load torque. This large starting current produces a large voltage drop in the line, which may affect the operation of other devices connected to the same line. Hence, it is not advisable to start induction motors of higher ratings (generally above 25kW) directly from the mains supply.

A soft starter is an additional device that can be added to a typical AC electric motor that will allow the motor to use a different startup method. The purpose of this device is to reduce the strain put on the motor during the typical power-up phase of a motor. To accomplish this, a soft starter will slowly and gradually begin applying increasing voltages to the motor. This allows for a smooth acceleration of power instead of a sudden and violent burst of power that could potentially cause damage to the motor and the machine as a whole.

Soft starter is an AC motor control device that combines soft start, soft stop, energy saving and multi-function protection. It can be used in place of motor starters to reduce the inrush current surge caused by large loads. So how does a soft starter start and stop a motor with a bypass contactor?

Soft starter is a motor control device that integrates motor soft start, soft stop, light load energy saving and various protection functions. It not only realizes the smooth and shock-free starting of the motor in the whole starting process, but also adjusts the parameters in the starting process, such as current limit value and starting time, etc., according to the characteristics of the motor load. In the normal working state of the ATO soft starter, the motor runs normally after pressing RUN, and the bypass contactor is normally closed. Next let's setup the soft starter.

Soft starter is a novel motor control device which integrates soft start, soft stop, light load energy saving and multiple protection functions. Its main structure is a three-phase anti parallel thyristor and its electronic control circuit connected in series between the power supply and the control...

Soft start technology is an emerging technology for controlling and starting motors. Nowadays, it has received extensive attention from modern people and is actively used in enterprise production activities. This technology can smoothly start the motor, reduce the voltage well, and can also compensate and frequency the motor, thereby effectively reducing the adverse impact of the motor starting on the power grid and related equipment, thereby effectively protecting various related equipment. Soft start technology has incomparable advantages compared with traditional start technology.