ABB ACS880 AE15 Excess Temp Difference

Is your ABB ACS880 showing AE15 Excess Temp Difference? Learn why your parallel power modules are out of sync and how to fix the cooling or load sharing today.

 

Solving ABB ACS880 Warning AE15: The "Excess Temp Difference" Guide

If you are operating a high-power ABB ACS880 (often a multi-module or parallel-connected drive) and the screen flashes AE15 Excess Temp Difference, the drive has noticed an internal imbalance.

In simple terms, the drive is comparing the temperatures of its parallel power units or internal heatsinks. If one module is running significantly hotter than its neighbors (usually a difference of more than 15°C), the drive triggers AE15. It’s a warning that one part of the drive is "working harder" or "cooling less" than the rest. Let’s look at how to balance it out.

Common Causes of the AE15 Temp Difference

When an ACS880 trips on AE15 for temperature reasons, it usually boils down to these four issues:

• Uneven Airflow: A cooling fan in one of the parallel modules has slowed down or failed, while the others are fine.
• Blocked Heatsink: Dust or debris has clogged the fins of one specific inverter module.
• Imbalanced Load Sharing: Due to a loose connection or a parameter setting, one power module is carrying more current than the others.
• Sensor Failure: One of the NTC temperature sensors has drifted and is reporting an incorrect "hot" reading.

Step-by-Step Troubleshooting for AE15

1. Check the Actual Temperatures (Group 05)

Before you open the cabinet, let the drive tell you exactly where the heat is.

• Go to Parameter Group 05 (Diagnostics).
• Look at the temperature readings for Inverter 1, Inverter 2, etc. (Parameters like 05.11).
• If Inverter 1 is at 60°C and Inverter 2 is at 80°C, you’ve confirmed the imbalance and identified exactly which module needs attention.

2. Inspect the Cooling Fans

In parallel drives, each module has its own fan.

• Listen and feel: Is the "hot" module's fan moving as much air as the others?
• Check for Fault 5080 (Fan Failure) in the history. Even if that fault hasn't tripped yet, a sluggish fan will cause the AE15 warning.

3. Check for Mechanical Blockages

Use a flashlight to inspect the air intake and exhaust of the specific module that is running hot.

• Clean out any dust, lint, or grease using clean, dry compressed air.
• In parallel-connected units, ensure the cabinet filters directly in front of the hot module aren't clogged.

4. Verify Electrical Balance (The "Tug Test")

If the temperatures are different, the Current might be different too.

• With the power Off and Locked Out, check the busbar or cable connections for each inverter module.
• A loose connection can create high resistance, causing one module to carry less load, which forces the *other* module to work harder and get hotter.
• Check Parameter 05.02 (Current sharing) if your firmware supports it.

How to Clear the AE15 Warning

1. Clean the heatsinks and ensure all fans are spinning at full speed.
2. Ensure the load is shared equally by tightening all power connections.
3. Because this is a Warning and not a Fault, AE15 will typically disappear on its own once the temperature difference between the modules drops back into the safe range (usually below 10°C–15°C).

Summary

The ABB ACS880 AE15 Excess Temp Difference warning is an early-warning system for parallel drives. It prevents one power module from burning out while the others stay cool. By checking Group 05 diagnostics and ensuring clean airflow, you can fix this imbalance before it turns into a total system shutdown.