ABB ACS800 Not Responding to Digital Input

4-20mA is not a digital input; maybe the configuration parameters need to change.

• The fault may be the incorrect setting of some of the parameters. Without being able to see the drive, it is not possible to determine which one(s).
• Another possibility is a short in the 4-20mA loop such that the current doesn't get to the input. Without seeing the wiring, it is not possible to eliminate this possibility.
• Another possibility is, as indicated in #1↑, the sending of an analog signal into a digital input, which is just a really silly thing to do.
• One wonders if all fuses are still intact, too. Again, site eyeballs and local test gear are needed.

So it's time to break out a Technician at the facility who knows about these things to fault-find at site. Do let the forum know what the problem was and what the fix was, as it would be valuable information for other readers.

In all drives, you must tell the drive, via program settings, where the start-stop command signal is going to come from and where the speed command is going to come from. Factory default settings are typically set to have the drive respond to the built-in HIM (Human Interface Module) for both of those because the factory has no idea how you may have wired up any external signals. So until you program it to respond to the signals that you connected, it ignores them.

Usually when you pay for factory authorized commissioning service, they would do all of that for you and teach you how it all works. Obviously, someone bought a very complex VFD, then foolishly got cheap and failed to spend a little more to make it work correctly.

Classic...

Thank You so much, I am new to drives so didnt put up question exactly, it was the problem of digital input START/STOP not the analog input, wiring was right the only thing was drive didn't know where START/STOP signal will come from. Adjusted the parameter and it is now working.

Thanks for responding.

So many "just disappear".

Please tell us which input channels are being used for 4-20ma signal and which digital inputs are being used for start / stop, or is it a contact closure?

Is it three wire or two wire start stop?

If you can provide a sketch of your input circuits, I will try and give you the program parameters. (I like a challenge!)

Would love to be able to expound on your problem, since I work extensively with AB and ABB drives, but you've received some invaluable advice already. But, I will add this....please be very careful. If you really need to ask these types of questions.... well my hope is you have access to a qualified electrician or EE who can assist you. Be safe!