Learn how to change teh LCD display (aka HMI) to show RPM instead of Hertz on the WEG CFW300 Variable Frequency Drive in this brief live demo tutorial. This is the best VFD, with a super low cost, but with high end features like Dynamic Braking, Fire Mode, PID, 65,000A SCCR, Zero Stack foot print, Multi-Speed, etc and is even cULus listed!
By default, the WEG CFW300 drive displays the output frequency. Can we change it to display rpm? Sure! I’m going to use this free WEG programming software as a parameter lookup tool. It isn’t actually connected to the drive in this video. If we look at the 400 parameters, my motor is set up for a rated speed for 1720rpm at 60 Hz. So, to convert the displayed rpm we just scale the display to 1720 instead of 60. Parameter 208 is the display scaling factor. We see it defaults to 600, but parameter 210 moves the decimal point over one digit, so we end up with 60-point zero hertz on the display. And parameter 209 selects the units to be displayed. So, all we need to do is change parameter 208 to scale the display to 1720, change parameter 209 to show rpm and change parameter 210 to zero decimal places. It’s important to remember this only affects the motor frequency DISPLAYS. Everything else in the drive still uses hertz. For example, if we go to parameter 121 to enter a motor speed – it is still in Hz. So, let’s tell the drive to run at half speed which would be 30 Hz. And scroll back down to view the motor output speed in parameter 2. Now if we hit run, the drive ramps up to half speed which is 860rpm. Perfect. Notice that the speed reference in parameter 1 is also in rpm. Again, this scaling only affects those two parameters. Because it only affects the display, you can scale the display to whatever you want. Feet of conveyor per minute, the shaft rotation after a gear box, etc. You can change the units from hertz, rpm, volts, percent or just turn them off. These three parameters give you a lot of flexibility over what you can display on the LCD, so use it to your advantage to present a display that is in units that make sense for your application. Click here to learn more about the WEG CFW300 variable frequency drive. Click here to learn about AutomationDirect’s free award-winning support options and click here to subscribe to our YouTube channel so you will be notified when we publish new videos.