The Siemens 3VU9135-1AB04-0RE0 is a busbar accessory designed for the 3VU13 switch series, providing a 3-phase busbar that connects up to four 3VU13 switches with a modular spacing of 3MW. This is a panel-integration component — it mounts within the switchgear assembly to distribute three-phase power across multiple motor-protective circuit breakers in a compact, ganged layout.
What the busbar does in the panel
This accessory replaces the need for individual phase wiring between adjacent 3VU13 switches. The 3-phase busbar bridges the line-side terminals of up to four breakers at the factory-defined 3MW spacing, so the panel builder gets a single mechanical and electrical assembly — fewer wiring errors, cleaner DIN-rail layout, and a lower voltage-drop profile across the group. It is sized for the 3VU13 frame only; verify compatibility with the specific switch variant before committing the BOM line.