AC drive is used for control AC motor speed by variable frequency, somehow it's the device to save electricity energy by adjusting the speed according to load's running period.

It's important for applications with motor in it, choose a suitable VFD drive is essential in money saving and protecting the motor, what's the most important factors to choose the drives, the brand? price? performance? how you think?

The Application should be considered first to select the AC drive, as this tells the majority of the story which should include what the application, drives and motor placement environment will be, the driven motor should also have been properly selected for the application and environment and utilized for Drive Sizing allowing adequate headroom for current and bus voltage levels to include motor lead length and input supply and output waveform filtering requirements.

Proper carrier frequency selection again for the application, proper cooling for both Drive and Motor, adequate and proper Voltage and Current Power Supply and conductors, proper grounding and grounding conductors, properly selected Output conductors considering length to motor, proper wiring layout, both control and power and correct sheilding/separation of types and voltage levels, correct control system architecture to support the application, stable and fast communications capability and selection which is necessary in the majority of systems today, also select the ac drive that can be supported and serviced in whatever part or parts of the globe the drive will be in when the unexpected occurs, with applications engineering support as well as technical and sales support.

After you look at all of this, call ABB, they'll be happy to assist and supply your every need.

few manufacturers make a drive with simple programming. It is easy to code in a so much application specific capabilities in the chips coming out now. So much room with little cost you may as well fill it up!

I have another aspect to variable frequency drive ownership in that once you have made a purchase you have to live with it. All manufacturers will give you some sort of MTBF data and salesmen will promise a long life for their product. But what is a long life for an electronic piece? Look at the installed components and line them up in order of time to fail. You will have capacitors first every time. They will need to be replaced at least once if you want a drive to last more than 10 years.

How easy is the VFD drive to work on? If a VFD failed would I fix it or replace it? Is this a 'throw away' drive that is not expected to be worked on? I take the long term view of ownership.