The ABB 1SFA894005R7020 is a PST50 soft starter rated for 50 A in-line connection (Ie), delivering 25 kW at 400 V. In an inside-delta configuration it handles 85 A and 45 kW — the delta wiring shifts the current path so the starter sees phase current while the motor draws line current, effectively doubling the power throughput for the same unit. Ramp time is adjustable from 0 to 120 seconds, with an initial voltage during start settable between 30 and 70 %. A step-down special ramp can drop voltage from 100 down to 30 %. Current limit function spans 1.5 to 7 times Ie. These give you control over the acceleration profile for pumps, conveyors, or compressors — soft starting avoids mechanical shock and limits inrush. Built-in electronic overload protection is integrated, with separate fault, overload, by-pass, and run signal relays — all screw-terminal connections. The control supply accepts 100–250 V AC; a separate 24 V DC control circuit is also available for logic-level interfacing.
Main circuit terminals accept rigid 1 x 10 to 95 mm² cable; control and supply circuits take 1 x 2.5 mm². Screw terminals with a control-circuit tightening torque of 0.5 N·m. The main terminals carry an IP10 degree of protection per IEC 60529 and IEC 60947-1 — finger-safe against accidental contact but not sealed against dust or moisture, so the unit belongs inside an enclosure rated for the environment. Ambient operating temperature range is 0 to +50 °C, with a 115 % service factor — meaning it can run at 115 % of rated current without tripping the overload, useful for high-inertia starts or occasional overload conditions.