Powerflex 40P VFD - Opto output parameter

[pssriram16]

I am using Powerflex 40P drive. I tied the opto output on the VFD terminal (pin 18) to PLC input. I used Drive explorer software to set the VFD parameter A061 (Opto Output selection) = "Motor Running". But when the motor is running, I don't see this output turn ON. Any ideas why? See attached picture.

Sriram

 

[EddieWillers]

The Opto outputs on a PowerFlex 40P are NPN transistors, so they are considered a "sinking" output.

Look carefully at the wiring diagram for the PowerFlex 40P and you'll see that the Opto outputs are usually used to run a brake relay and that +24V is applied to the "Output" pins 17 or 18, and DC common is connected to the Opto Common pin.

Your PLC input needs to be a "sourcing" type to use it with the PowerFlex 40P opto outputs.

This is based only on my reading of the publications; I have not made such a connection myself.

 

[pssriram16]

There is a DIP switch on the VFD to choose between "Sinking" and "Sourcing".

 

[EddieWillers]

The Sinking/Sourcing slider switch affects the Digital Inputs on the drive, not the Opto Outputs.

This is illustrated in the Control Wiring Block Diagram on page 1-15 of the PowerFlex 40P User Manual, Publication 22D-UM001.

As far as I can tell, the Opto Outputs are always a "Sinking Output", so if hooked to a PLC they would require a "Sourcing Input".

An interposing relay would be a simple way to work around this issue if you have only Sinking Inputs available.