Under what circumstances is it necessary to increase the capacity of the inverter?

The "increase the capacity of the inverter" mentioned here refers to the fact that the capacity of the motor equipped with the inverter is equal to the actual motor capacity. 

Generally speaking, it can be summarized as follows:

01 The rated current of the inverter is too low.

As mentioned above, when the rated current of some inverters is less than the rated current of the motor of the same capacity, a larger inverter should be selected according to the load of the motor.

02 The motor may be overloaded for a short time.

Because the so-called "short time" of the motor is relative to the heating time constant. It can be as short as a few minutes or as long as dozens of minutes. 

The overload capacity of the inverter is usually 150%, 1min. Compared with the motor, it is equivalent to no overload capacity. 

Therefore, if the motor may be overloaded during the think tank time, the capacity of the inverter should be increased.

03 Those with special requirements for acceleration and deceleration time.

The length of the motor acceleration time is a relative concept related to the size of inertia. 

For loads that need to start and stop under heavy load, the capacity of the inverter should be increased in the following cases:

(1) Those who require fast starting and stopping;

(2) Those who frequently jog.

04 Those with impact loads

For example, the motor and the load are connected through a clutch. Usually, when the motor is already rotating, the clutch is engaged, causing the load to rotate as well. 

At the moment the clutch is just engaged, the motor speed will drop, the slip will increase, and the current will also increase, which may cause overcurrent protection to operate.

In this case, the capacity of the inverter should be increased.