Analysis of soft starter selection and common power
Soft starter is a new type of starter developed to improve the starting performance of large and medium-sized wound AC asynchronous motor
1. According to the voltage classification: high voltage soft Du starter, low voltage soft starter;
2. According to the medium classification: solid soft starter, liquid resistance soft starter;
3. According to the control principle: electronic soft starter, electromagnetic soft starter;
4. According to the operation mode: Online soft starter, bypass soft starter;
5. According to the load: standard soft starter, heavy load soft starter.
What is the common power of soft starter?
There are many commonly used power of soft starter, such as 37, 55, 75 in the general market, and many are also relatively common, such as 5.5, 7.5, 11, 15, 18.5, 22, 30, 45, 90, 115, 132, 165, 185, 200, 225, 250, 280, 320, 400, 500, 600, etc.
When the motor power exceeds 10kW, step-down starting can be adopted; The starting current is five to eight times of the operating current; Or the motor capacity is greater than 30% of the transformer capacity; Or use the following formula to judge: the ratio of starting current to rated current is less than or equal to three fourths + transformer capacity / four times of motor capacity; If the above formula is not satisfied, start with reduced pressure