Here said“Increases the frequency converter capacity”, is relative to the frequency converter with the motor capacity is equal to the actual motor capacity. In general, it can be summarized as follows:

01

The rated current of the converter is low

As mentioned above, when the rated current of some frequency converters is less than the rated current of the same capacity motor, the frequency converter with big first gear should be selected according to the load condition of the motor

02

The motor may overload for a short time

Because the motor so-called“Short time”, is relative to the heating time constant. As little as a few minutes, as many as dozens of minutes. And the overloading capacity of the inverter, usually 150% , 1 min. Compared with an electric motor, it has no overload capacity. Therefore, if the motor may be overloaded during the think tank time, the inverter capacity should be increased.

03

Special requirements for acceleration and deceleration time

The acceleration time of motor is a relative concept related to inertia. For example, an acceleration time of 5s may be too short for a load with large inertia (GD2 large) , but may be too long for a load with small inertia (GD2 small) .

In general, for loads that require starting and stopping under heavy loads, consider increasing the capacity of the converter in the following situations: 

(1) Requires ability to start and stop quickly; 

(2) Click more frequently.

04

Those with impact loads

For example, the motor is coupled to the load through a clutch. Usually in the motor has been rotating state, due to the combination of the clutch, so that the load is also rotating. Obviously, in the clutch just combined the moment, the motor speed will decline, slip increase, the current also increases, may lead to overcurrent protection action. In view of this situation, should increase the capacity of the inverter.

Source: internet (for study only, intrusion and deletion)