Mounting and panel fit — busbar snap-on
The 3RA2120-1KD24-0FB4: Designed for snapping onto 60 mm busbar systems, the 45 mm width and 260 mm height fit a standard S0 feeder footprint — the 165 mm depth leaves room for wiring ducts in a 400 mm deep enclosure. Clearance requirements: 50 mm above, 20 mm in front, 20 mm at the sides, and 10 mm below — no clearance needed at the back. The vertical mounting position is mandatory for proper thermal bi-metallic release operation.
Protection and termination details
The thermal bimetallic overload release provides adjustable overload protection; the magnetic short-circuit trip handles fault interruption. Main circuit connections are screw-type terminals — no special tooling needed for field wiring. Supplied as a complete assembly: contactor 3RT2024-1FB40, link module 3RA2921-1BA00, and busbar adapter 8US1251-5NT10 — all pre-configured for 60 mm busbar mounting.
Environmental limits and storage
Operates from -20 to +60 °C with temperature compensation; storage and transport range is -50 to +80 °C. The 24 V DC coil is rated at 24 V nominal — confirm the control supply matches the solenoid draw.