Reversing starter for busbar-mounted motor control
The Siemens 3RA2225-1BD23-0BB4 is a SIRIUS non-fused reversing motor starter — a compact assembly that combines a reversing contactor pair and a thermal bimetallic overload relay in one unit that snaps directly onto a 60 mm busbar system.
Mounting and envelope constraints
Size S0 load feeder with a 90 mm width, 260 mm height, and 165 mm depth — fits standard 200 mm deep enclosures with clearance for the busbar adapter below. Requires 30 mm clearance above and 10 mm below for wiring and airflow; no clearance needed at the rear because the busbar adapter (8US1251-5NT10) carries the power in the same plane. Mounting position is vertical only — horizontal orientation shifts the bimetallic trip characteristic and voids the thermal calibration.