Undertorque Detection 1

What does UL3 mean?

This fault indicates that the drive's output current dropped below the level set in L6-02 for longer than the time specified in L6-03. This is typically caused by a mechanical issue like a broken pulley belt, or by incorrect load parameters for the application. Continued undertorque can lead to inefficient operation, unnoticed mechanical failures, or unexpected machine stops.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Perform a Fault Reset to clear the fault from the drive once the underlying mechanical or parameter issue is resolved.