The ABB ACS350‑03U‑44A0‑4 is a 30 HP, 440 VAC three‑phase AC drive with DC‑injection braking and advanced digital control. Common failure modes for this series include overcurrent protection trips due to motor winding faults or shorted capacitors, DC‑injection injector failures causing loss of dynamic braking, firmware glitches that trigger error codes such as “E001” (motor overload) or “E003” (encoder fault), and power supply issues like sagging input voltage or tripped residual‑current devices. For initial troubleshooting, verify the 380–480 VAC input is stable and within rating, inspect the drive’s internal fuse and capacitor bank for signs of damage, and review the diagnostic display or communication logs for recent error codes; also confirm that the motor and encoder connections are secure and properly grounded.[oss-gpt-20b]