How to carry out inverters selection work is a hard problem faced by many technicians and business person in many enterprises. In purchasing inverters, don’t just think about power of inverters by just ignoring whether the load performance is matched with its capacity. In the following part, 15 golden rules for inverter selection are given.

1. Suitable inverter should be selected as per the load feature;

2. In selecting an inverter, the practical motor current value shall be considered as the basic standard while the rating power of the motor is just a reference. Moreover, you should consider that if output of an inverter contains ultraharmonics, the power factor and efficiency of the motor will go bad.

3. In case an inverter shall operate by long cables, output terminal of the inverter shall be equipped with output electric reactor.

4. When an inverter is used to control several motors in parallel, the total cable length between the inverter and the motor and the allowable range shall be considered;

5. For some special application occasions such as in high temperature environment, high switch frequency, high elevation, etc. reduction of capacity of the inverter maybe caused and the inverter shall be selected by amplifying a gear;

6. When choosing inverter for high speed motor, the inverter shall be bigger than a common motor;

7. When an inverter is used for a multi-pole motor, capacity of the inverter shall be fully considered to make sure the maximum rating current is less than the rating current of the inverter;

8. When driving anti-explosion motor, the inverter shall be put in a position far away from the explosion danger as there is no anti-explosion structure in the inverter;

9. When using an inverter to drive gear deceleration motor, the usage range is limited by the lubrication way of the gear drive part. It shall not surpass the allowed maximum rotation speed.

10. When an inverter is used to drive a coil wound rotator asynchronous motor, overcurrent tripping phenomena is easily caused due to frequent ripple current. So inverter with relatively bigger capacity shall be selected;

11. When an inverter is used to drive synchronous motor, the output capacity shall be reduced by 10% to 20% capered with the power frequency power supply;

12. As for the application cases with big wave torque loading such as compressors or vibrators, or application cases with peak value loading such as oil pump, power frequency operation state shall be learned about to choose inverter with a rating output current higher than maximum current of the loading device;

13. When an inverter is used to control a Roots blower, you should consider whether capacity of the inverter is big enough in the choosing process;

14. Check if the protection grade of the inverter to be chosen is matched with the on-site condition;

15. Single-phase motor is not suitable to be driven by an inverter.