SIRIUS reversing starter — S0 frame, 24 V DC, snap-on rail
The 3RA2225-1GB24-0BB4: This is a Siemens SIRIUS 3RA2 reversing motor starter, size S0, combining a 3RT2024-1BB40 contactor, a thermal bimetallic overload relay, link module 3RA2921-1BA00, and busbar adapter 3RA2922-1AA00 in one assembly. Snap-on mounting to 35 mm standard rail in vertical position — it occupies 90 mm of rail width, so budget that space in the panel layout alongside the upstream circuit breaker.
Motor ratings and wiring — what the numbers mean for the build
At 460/480 V it handles 3 hp; at 575/600 V it handles 5 hp. The maximum AC-3 switching voltage is 690 V, so it covers 480 V and 600 V motor circuits without issue. The thermal bimetallic overload with Class 10 trip protects standard squirrel-cage motors during start-up — it lets the motor pull locked-rotor current for up to 10 seconds before tripping, which matches most pump and fan starting profiles. Main contact wire range accepts 1 to 10 mm² stranded, or 2x (2.5 to 6 mm²) — practical for the 4.8 A at 480 V and 6.3 A at 600 V ratings; you are not fighting undersized terminals.
Mounting clearances and panel fit
The starter needs 30 mm upwards, 10 mm forwards, 10 mm downwards, 9 mm at the side, and 0 mm backwards for cooling and arc clearance — that 30 mm above the unit is the critical dimension; do not crowd it against the gland plate. Overall dimensions: 130 mm deep, 90 mm wide, 265 mm high. The depth is the front-to-back rail dimension — check the enclosure depth against 130 mm plus wiring space behind. Pollution degree 3 means it is rated for industrial environments where conductive dust or occasional condensation occurs — no need for a sealed enclosure, but keep the panel clean.
Lifecycle and sourcing — active, quoted to order
No stock-holding claim — quoted per BOM quantity. Substance prohibition date of 03/01/2017 indicates RoHS compliance per the EU directive — the starter meets the material restrictions for CE-marked equipment.