3-Wire control of a VFD ensures that the drive won't automatically start running after a power disruption. See how simple it is to setup in this short video 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!
You can download the software for free at www.automationdirect.com
The cool thing about a momentary 3-wire run stop control is if you lose power to your system, when the power returns, the drive has to see someone push the start button to start running again. A two wire on/off toggle switch will still be closed so the drive will start right back up when the power returns. In many applications that could be dangerous, so a 3-wire run stop is a handy feature FOR A DRIVE to. I’m using this rectangular pushbutton to provide one momentary normally open contact to Digital Input 2 - which will be our RUN command - and a momentary normally closed contact to Digital Input 3, which will be our STOP command. Let’s do a Factory reset so we are starTing from the same place. You can do the entire setup from the HMI on the drive, especially since we are only going to modify three parameters. But, I’m going to use the WPS software for this demo because it’s easier for you to see what I am doing. Just know that you don’t have to use the WPS software and extra accessories it requires. I’ve already created a configuration and a resource for my drive, and these are the parameters I ALREADY setup for my motor. Yours will probably be different. I’m also connected to the drive. Let’s bring up the parameter list and search for DIGITAL Input 2. Looks like Parameter 264 is where we specify it’s function so let’s set that at 3-wire start. Search for Digital Input 3 .. and set his function to 3-wire stop. I’ll be running the drive in LOCAL mode, so let’s search for local and we see he defaults to HMI run stop control. Let’s change that to Digital Input control. That’s it. Were done. If I hit the run pushbutton, the drive runs. If I hit the STOP push button, the drive ramps to a stop. That’s all there is to it. Let’s do one more thing. This switch has an indicator on it. Let’s setup a Digital output to turn that indicator on when the drive is running. I’ll just search on Digital Output and change DO1’s function to Run. That simply indicates the run status of the drive. I wired the drive’s digital relay output normally open contact like this to the indicator in the switch. Now when we hit RUN the indicator lights up and when we hit stop, the indicator turns off once it’s ramped to a stop. Perfect. One side note: The light stays on as long as the RUN command is active – even at zero speed. That way you know if the drive has actually been stopped or if it is still running but at zero speed. Click here to learn more about the WEG CFW300 family of drives. 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.