Rated current and thermal derating
The 3RW4026-1BB15: That 40 °C derating temperature means the full 25 A is only available up to that point — above it, the thyristor junction temperature limits the output. For a 400 V motor drawing 22 A FLA in a 50 °C cabinet, this unit lands right at the derated 23 A ceiling; no headroom for overload cycling.
Mounting and panel fit
Size S0 frame, 45 mm wide, 125 mm tall, 155 mm deep — fits a standard 45 mm DIN-rail slot with screw or snap-on fastening. The mounting position is flexible: with the optional fan, the unit rotates ±90° on a vertical surface and tilts ±22.5° front-to-back; without the fan, rotation is limited to ±10°. Clearance requirements: 60 mm above, 40 mm below, 15 mm at the sides for airflow and wiring access.
Control supply and wiring
Control supply is 110-230 VDC, with screw-type terminals for both the main current circuit and auxiliary/control circuits. Maximum wire length to the motor is 300 m — beyond that, voltage drop on start and cable capacitance can cause nuisance trips on the thyristor gate drive.
Integrated protection and bypass
Built-in motor overload protection and intrinsic device protection (thyristor overtemperature, phase imbalance) are standard. The adjustable current limitation lets you set the start current between 20% and 100% of the rated current — useful for soft-starting conveyors or pumps where the breakaway torque is low. The integrated bypass contact system shorts the thyristors after start, eliminating semiconductor conduction losses during run; the unit runs cool and the bypass relay handles the continuous current.
Environmental and compliance
Operating temperature range -25 to +60 °C; storage -40 to +80 °C. Storage class per IEC 60721: 1K6 (occasional condensation), 1C2 (no salt mist), 1S2 (sand ingress prevented), 1M4 (mechanical). Insulation voltage rated 600 V, operating frequency 50-60 Hz.