Applicable Systems
AC500
AC590
ACS580
ACS880
Symptoms
Run enable signal missing. The drive is ready to run but the external Run Enable signal is not present. The motor cannot start until the enable signal is restored.
Possible Causes
- Run Enable digital input not receiving 24V signal
- Run Enable wiring broken or loose at the terminal
- PLC or controller not sending the enable signal
- Drive digital input configuration incorrect (wrong input assigned)
Troubleshooting Steps
- Step 1: Check the Run Enable digital input terminal for 24V DC signal
24V DC present at the terminal when enable is expected - Step 2: Verify wiring from the PLC or controller to the drive input
Wire continuity is good; no broken connections - Step 3: Check the PLC program is sending the enable signal
PLC output is ON; LED indicator on PLC output module is lit - Step 4: Verify the digital input parameter assignment matches the wiring
Run Enable is assigned to the correct input terminal
How to Reset
1) Check input terminal voltage. 2) Verify wiring. 3) Check PLC output. 4) Verify input parameter. 5) Reset fault.
Frequently Asked Questions
- Q: How do I configure which input is Run Enable?
In the ABB Drive Composer Pro or the HMI, navigate to Parameters > I/O > Digital Inputs. Assign the Run Enable function to the desired input terminal (e.g., DI1, DI2, etc.).
- Q: Can I bypass Run Enable to test the motor?
Temporarily, yes. You can assign Run Enable to always ON in the parameters for testing. However, for production, always restore the proper safety circuit.
Source: ABB ACS880 Firmware Manual, ABB Oy
Category: PLC & VFD