Selection of inverter protection structure and protection level

The heat generated inside the inverter is large. Considering the economical efficiency of heat dissipation, almost all of the open-type structures except the small-capacity inverter use forced cooling by a fan. When the inverter is used outdoors or in a harsh environment, it is best to install it on a separate disk and use a fully enclosed structure with a heat exchange device for cooling. For small-capacity inverters, a fully enclosed structure can also be used in dusty, oily environments or textile mills with many lint.

When selecting the inverter, be sure to check whether the protection level matches the situation on the spot. Otherwise, the dust and water vapor on the site will affect the long-term operation of the inverter.

In short, the choice of frequency converter also needs to be flexible for the specific requirements of specific production machinery. In many cases, based on experience or recommendations from suppliers, some practical methods can be used to make the speed control system operate reliably and ensure optimal investment.

Precautions:

(1) When selecting the inverter, the actual motor current value should be used as the basis for the inverter selection. The rated power of the motor can only be used as a reference.

(2) It should be fully considered that the output of the inverter is rich in high-order harmonics, which will deteriorate the power factor and efficiency of the motor.

(3) Comparing the power supply to the motor with the inverter, the current of the motor will increase by 10%, and the temperature rise will increase by about 20%. Therefore, when selecting the motor and the inverter, this situation should be taken into account, and a margin should be left to prevent the temperature rise from being too high and affect the service life of the motor.