What this part does in the panel
The Siemens 3RK1901-3CA00 is an AS-Interface support bracket designed for a load feeder module, sized at 45 mm wide and intended for mounting on a busbar with 60 mm center-line spacing. It includes provisions for PE and neutral conductor connection, so it handles the protective earth and neutral distribution for the feeder module it carries. This is the mechanical and electrical backbone that positions the load feeder on the busbar and ties it into the AS-Interface network. One critical detail: the 3RK1901-3CA00 requires the 3RK1901-0EA power connector set to function. If you're sourcing this for a new build or a replacement, make sure that connector set is on the BOM — the support bracket itself does not include the power tap.
Panel fit and integration
At 45 mm wide, the 3RK1901-3CA00 occupies a single standard busbar slot on a 60 mm center-line rail. The PE and neutral conductor connection is built into the bracket, so you don't need a separate terminal block for those conductors at this point in the panel. It supports the AS-Interface load feeder module — think of it as the mounting cradle that also carries the network and power distribution for that module.