Under What Circumstances Must a Soft Starter Increase Capacity

2021-02-08

Soft starters, as the "gentleman" who accompanies the motor to start, are one of the electrical devices that we often use in the industry. So, have you ever had an in-depth understanding of soft starters? Under what circumstances must the capacity of a soft starter be increased?

There are several situations in which the capacity of a soft starter must be increased.

1. Soft starters in online full-voltage operation or soft starters using energy-saving control methods often operate under heavy load. Since the rated current of the soft starter is relatively small compared to the motor of the same class, the current margin is relatively small. Therefore, if the motor is often run under heavy load, its operating current will easily exceed the rated current of the soft starter, which may cause the soft starter to overload during operation, so the capacity of the soft starter should be increased appropriately.

2. The motor is used for continuous load changes or intermittent loads with short cycles. In this case, the motor is not allowed to run under short time overload, otherwise, the soft starter may be overloaded during operation, so the capacity of the electronic soft starter should be increased appropriately.

3. The motor is used for a repeated short-time working system, and the cycle is less than the starting interval specified by the manufacturer, then it may cause soft start overload during starting, therefore the capacity of the soft starter should be increased appropriately.

4. Some loads are too heavy, or the grid capacity is too small, during starting, the motor starting time is too long, so that the soft starter overload trips, then the capacity of the soft starter can be enlarged appropriately under the premise that the motor will not be damaged.

5. For loads with special requirements on acceleration time, the length of motor acceleration time is a relative concept related to the size of inertia. Some loads require a shorter acceleration time, the acceleration current of the motor will be relatively large, which can be solved by appropriately enlarging the capacity of the soft starter.

6. Loads with a large inrush current during the transition process may lead to over-current protection action, which can be solved by appropriately enlarging the capacity of the soft starter.