PowerFlex 525 fault on Network even in LOCAL control

[hunter44102]

So our Powerflex 525's are set up to allow REMOTE operation from PLC through network. But if network is lost we want to be able to run in LOCAL with local display panel.

However when network is lost we get a fault. There is a Parameter 'comm loss action' C125:
0= FAULT
1= Coast Stop
2= Stop
3= Continue LAST

Do I just set it to anything OTHER than 0 so that it doesn't get a FAULT which prevents it from starting LOCALLY?

So basically if our network goes down we would like to switch the dial to LOCAL and input the speed and start it locally but whoever configured this system didn't test what happens if network disconnects.

 

[joseph_e2]

On a drive where I'm just monitoring, I generally sets that parameter to 3: Continue Last.

There are other parameters that tell the drive which speed ref and which start/stop command to use based on digital inputs. When you clear the network loss fault, do the local controls work?

 

[hunter44102]

On a drive where I'm just monitoring, I generally sets that parameter to 3: Continue Last.

There are other parameters that tell the drive which speed ref and which start/stop command to use based on digital inputs. When you clear the network loss fault, do the local controls work?

Good question will try clearing and running it

 

[joseph_e2]

Either way, I would probably change that parameter to Continue last unless it's possible that there won't be anyone nearby to detect it and take control. You'll have to decide if it's safer to have it stop instead.

 

[OkiePC]

In addition to altering the communication loss mode (if safe for operators and operations), I would lean toward having a selector switch to a digital input on the drive that allows control source to be switched from network to local. That way, it can be done quickly and easily without having to manually change parameters in an emergency.

I don't know the parameters of that VFD intimately enough to say for sure how to do this, but it is a common practice for most every VFD.

 

[robertmee]

In addition to altering the communication loss mode (if safe for operators and operations), I would lean toward having a selector switch to a digital input on the drive that allows control source to be switched from network to local. That way, it can be done quickly and easily without having to manually change parameters in an emergency.

I don't know the parameters of that VFD intimately enough to say for sure how to do this, but it is a common practice for most every VFD.

Easy to do on a 525. Configure an Input as Source and Control select. You can even preset Control Source 2 to 2-wire and Control Speed 2 to HMI speed, so just configure the Input to select between Source 1 and 2.