Here's a breakdown of the product code ACS550-01-03A3-4:

ACS550: This indicates that the drive belongs to the ACS550 series.

01: This refers to the drive's enclosure type. In this case, "01" represents a wall-mounted, standard enclosure.

03: This indicates the voltage and power range of the drive. The "03" suggests that this particular model is designed to operate with a three-phase power supply within a specific voltage range.

A3: This represents additional features and options that may be included with the drive. The specific meaning of "A3" would be defined in the product specifications or documentation provided by ABB.

4: This refers to the firmware version of the drive. The firmware is the software that runs on the drive's control system.