What the 5 A AC-3 rating means for your motor load
This unit integrates a motor brake output (400 V AC) so it handles direct-on-line starting with an external brake coil — common for hoists, conveyors, and machine axes that need a holding brake. The two digital inputs on the AS-Interface bus let you wire limit switches or E-stop feedback directly into the starter, reducing separate I/O modules.
Where this starter fits in a panel
At 205 mm deep, 245 mm wide, and 215 mm tall, the 3RK4320-3KQ54-0BA3 is sized for a standard enclosure with enough depth for the AS-Interface connection and wiring. IP54 protection means it handles dust and splashing water, so it fits in control cabinets on factory floors or in light industrial environments where occasional washdown isn't directed at the enclosure. The control supply is 20.4 to 26.4 V DC, so it takes a standard 24 V DC power supply from the cabinet bus. The main circuit is three-pole, rated for 340 to 440 V AC at 50 or 60 Hz.