Reversing starter for busbar-mount panels
The Siemens 3RA2220-1FH24-0BB4 is a SIRIUS reversing starter — a pre-assembled combination of a contactor pair and overload relay in one unit, sized S0, designed to snap onto 60 mm busbar systems.
What the 5 A AC-3 rating means for fit
The 5 A at AC-3, 400 V rating is the motor-switching current — the contactor pair is sized for reversing duty on a motor drawing up to 5 A under full load. At 460/480 V the same unit is rated 3 hp, and at 575/600 V it carries 5 hp.
Snaps directly onto 60 mm busbar systems — no DIN rail required. The unit is 165 mm deep, 90 mm wide, and 260 mm tall, with a vertical mounting position specified. Clearance: 50 mm upwards, 32 mm forwards, 10 mm downwards, and 10 mm at the side; backwards clearance is 0 mm, so the back of the unit can sit flush against the panel backplate. Main circuit wiring uses spring-loaded terminals — no screw torque to verify, just strip and push in. The supplied contactor is 3RT2024-2BB40 and the link module is 3RA2921-2AA00.
Sourcing and lifecycle — active production
No stock-holding claim — sourced per RFQ through independent distribution.