The 3RW3026-2BB04 is a SIRIUS-brand soft starter in the S0 frame size, rated 25 A continuous at 40 °C. Insulation voltage is 600 V, so it covers 400/480 V systems with headroom. The integrated bypass contactor means no external bypass relay is needed — the thyristors are shorted after start, eliminating SCR heat dissipation during run. Minimum load is 10 % of rated current, so it cannot soft-start a motor drawing less than 2.5 A. Control voltage is 24 V AC/DC, matching standard industrial supplies. The unit operates on 50 or 60 Hz without derating.
Spring-loaded terminals, 45 mm wide — panel fit
Main and control circuits use spring-loaded terminals — tool-less wiring for solid or ferruled stranded conductors, resistant to vibration loosening. The main circuit accepts 16 to 8 AWG; auxiliary and control terminals accept 24 to 14 AWG. The S0 frame is 45 mm wide, 150 mm deep, and 150 mm high. Mounting is by screw or snap-on onto a DIN rail. Clearance requirements: 60 mm above, 40 mm below, 15 mm at the sides — needed for ventilation and wiring access. Pollution degree 3 per IEC 60947-4-2 suits industrial panel environments with conductive dust or moisture. Maximum motor cable length is 300 m — beyond that, output filter or ferrite may be needed to prevent reflected-wave damage to motor insulation.
No overload relay, no current limit — external protection required
The 3RW3026-2BB04 does not include motor overload protection, intrinsic device protection, or adjustable current limitation. A separate overload relay (e.g., Siemens 3RU2 or 3RB3) must be wired in series for thermal motor protection. This is standard for basic soft starters — the trade-off is lower cost and smaller footprint versus all-in-one starters.