DC BUS LIM

What does 3211 mean?

The ABB ACS800 drive is limiting torque due to the intermediate circuit DC voltage being either too high or too low. This is an informative alarm (3.18 AW5 bit 9) that indicates the drive is actively protecting itself by adjusting its output, and its behavior can be configured via programmable Fault Function 30.23.

• Intermediate circuit DC voltage is outside the acceptable operating range (either excessively high or critically low).
• Incorrect Fault Function parameters, specifically 30.23 (LIMIT WARNING), which activates or deactivates this limit alarm.
• Transient load conditions causing rapid changes in DC bus voltage (e.g., sudden regeneration or heavy acceleration).
• Issues with the AC supply voltage (e.g., sags, swells) affecting the DC link rectifier.

Click steps to track your progress.

1. 1

   Monitor the actual DC bus voltage at the drive's DC link terminals and compare it to the ABB ACS800 drive's rated voltage and allowed operating range.

2. 2

   Verify the AC supply voltage to the drive is within specifications and stable, checking for voltage sags or swells at the input terminals.

3. 3

   Check parameter 30.23 (LIMIT WARNING) settings to ensure this informative alarm is configured as desired and not causing unintended trips.

4. 4

   Evaluate the application load profile for sudden regenerative or heavy motor loads that might cause transient DC bus voltage fluctuations.

5. 5

   Inspect the braking resistor and chopper circuit (if applicable) for proper operation and connections, as issues there can affect DC bus voltage under regenerative conditions.