IronHorse ACN NEMA 4X VFD Two Wire Control from AutomationDirect

?There are multiple ways you can control the drive from the digital inputs. This video uses the 2-wire approach. That is, one normally open maintained contact enables the drive in the forward direction, the other normally open maintained contact enables it in the reverse direction. This is great for things like pumping or HVAC or cooling applications where after a power outage you usually want the system to come back on line immediately without human interaction. An the good news is this is the drive’s default configuration, so we don’t have to change any parameters on a factory fresh drive! We just wire the run forward switch to input terminal P1 and the run reverse switch to terminal P2 with both commons going to the common terminal. These are the five built-in digital IOs, their corresponding parameters and the default configuration for the two wire control. If you need to use a different pin just move the forward and reverse codes to which ever pins you want to use. You can see what the default usage is for each input terminal in the quick start guide. The Forward enable and reverse enable we’re using in this video. Output Block. That disables the output of the drive. Alarm reset, and the first speed selector bit. We’ll cover those in other videos. I used this two wire control wiring diagram to wire these toggle switches to the drive. By the way, you can add additional IO using the optional Extended IO module. It has an additional 2 analog in, 1 analog out, 3 digital inputs and 2 relay outputs. These are the parameters you will need to configure the extended digital inputs. This drive doesn’t use input P6 or P7. These are the other defaults. We’re not using them in this video, I’m just including them for your reference. Here’s peek at the wiring – that’s literally all there is to it. I love that this NEMA-4X ACN drive comes with a built in disconnect – you can also order it without the disconnect – so let’s fire this thing up and reset the drive to factory default so you know exactly where I am starting from by going to the drive group … parameter 93 … and setting it to a 1. Select that, accept it. Escape back to the frequency display. Hit enter and change the frequency to something we’ll recognize, how about 8 hertz. Hit enter to select and enter again to accept. The acceleration and deceleration times default to 20 and 30 seconds, so let’s speed those up just to keep the video moving. I’ll up arrow to the acceleration parameter and change it from 20 seconds to 4 seconds. Select that, accept and then up arrow to the deceleration and set that to a 5 just to have something different. Escape back to the frequency display. Hit run. Nothing. What’s wrong? Well, we told the drive to use these switches to enable the drive, so of course the key pad doesn’t work. Let’s tell the drive to run in the forward direction. There we go! It ramped up to 8 Hz in the forward direction and we see the RUN and Forward LEDs are lit. Turn that off, let it spin down and enable the reverse direction. Perfect. Eight hertz in the reverse direction. What happens if we turn BOTH switches on? The drive doesn’t acknowledge that so it disables the output. You can even see the run, forward and reverse LEDs are all off. If I release the reverse, then the drive spins up in the forward direction. Well, that’s it. But, there is one problem with this setup. If you lose power to the drive, and then the power is restored while these switches are enabled, the drive will jump right back to life – which could be dangerous. So a lot of folks prefer three wire control where just a momentary press starts the drive in either direction and a momentary stop button stops the drive. Now the drive looks for the transition, not the maintained switch closure which is a much safer way to control the drive. Check out this video to learn how to do that. That should be enough to get you started with using the 2-wire control, which again is the default for the drive. Click here to learn more about the Ironhorse NEMA 4X ACN family of drives. Click here to learn about AutomationDirect’s free award-winning support team and click here to subscribe to our YouTube channel so you will be notified when we publish new videos like these.