How much power does the motor need to use the Soft Motor Starter Cabinet?
The commonly used the Soft Motor Starter Cabinet can be divided into two categories, namely cage motor soft starter and liquid resistance starter. Many friends who are not very familiar with soft starter may have some confusion about what kind of power motor needs to use soft starter. Today, Zhang Gong from Xiangyang Yuanchuang Industrial Control Co., LTD., the manufacturer of soft motor starter, will answer your questions.
Classification of the Soft Motor Starter Cabinet:
YLQ series cage motor solid soft starter, its working principle is to collect current and voltage signals from the stator loop of the motor, through the special transformation processing, to control the on-state of three two-way thyristor, and then control the starting current of the motor and the input power of the motor running, to achieve the purpose of soft start of the motor.
2. YRQ series liquid resistance starter, its working principle is to string specially prepared liquid resistance into the rotor loop of the controlled wound motor, and by adjusting the concentration of the electrolyte and changing the distance between the two plates, the liquid resistance value always meets the requirements of the mechanical characteristics of the motor on the string resistance value during the starting process. Thus, the motor obtains the maximum starting torque and the minimum starting current, and then starts smoothly.
The specific working process is: when the main motor starts, the moving plate moves slowly under the drive of a small power transmission mechanism system, changes the distance between the two plates, so that the liquid resistance into the rotor loop changes to meet the above conditions, and the motor speed increases. When the distance between the two plates is minimum, the motor speed reaches the rated speed, and the liquid resistance is short-connected to complete the starting process and turn into the running state.
For the motor under 400V voltage, generally speaking, measures should be taken to reduce the starting current above 7.5kW. The best is the frequency converter soft starter and other equipment to start, of course, you can also choose automatic step-down start and star triangle and other starting methods to start the motor. If speed regulation is required, the motor must be started with a frequency converter.
In fact, the soft starter of multi-power electric machine mainly depends on the ratio of motor power and power supply size, as well as the allowable value of the influence of line voltage drop. Look at the capacity of the power supply, the greater the capacity of the power supply, the greater the capacity of the power supply to withstand the initial impulse current and then reduce the input cost of the starter based on that.
If the motor with more than a certain power does not use soft starter frequency conversion and other starting methods, it will cause a large current in the main circuit of the starting motor. First, it will affect other electrical equipment on the entire power grid, and then the aging of electronic devices and the wear and tear of mechanical equipment. The most important thing is that the motor may not be able to start normally.
