What this PST30 variant delivers
The ABB PST30 1SFA895002R7020 is a soft starter sized for 30 A in-line connection and 52 A inside-delta connection, with a rated operational voltage of 400 to 690 V AC at 50/60 Hz. The inside-delta wiring lifts the motor current handling to 52 A and rated power to 25 kW at 400 V, versus 15 kW in-line — so the delta configuration is the one to spec for a 25 kW motor load. Built-in electronic overload protection (1.5–7× Ie current limit) eliminates the need for a separate overload relay in the panel. Ramp time is adjustable from 0 to 120 seconds, with an initial voltage during start of 30–70 % and a step-down special ramp from 100–30 %. That range covers soft starting for conveyors, pumps, and fans where a controlled acceleration and deceleration reduces mechanical shock. The control supply voltage is 100–250 V AC; the control circuit also accepts 24 V DC for the logic side. Communication is via the standard FieldBusPlug, meaning it accepts ABB's fieldbus adapter modules for PROFIBUS, DeviceNet, or similar networks — the plug itself is the physical interface, not a built-in protocol stack. Screw terminals on the control circuit (0.5 N·m torque) and main circuit (rigid 1 x 10–95 mm²) keep wiring straightforward for panel builders.
Signals and protection built in
Four signal relays are onboard: run, fault, by-pass, and overload — each a dry contact for the PLC or status lamp. A red LED indicates a fault condition; a yellow LED signals protection active. The unit also includes a switch for inside-delta connection, so the wiring changeover is internal, not an external contactor reconfiguration. Degree of protection for the main terminals is IP10 per IEC 60529 and IEC 60947-1 — finger-safe against accidental contact but not sealed against dust or moisture. The ambient operating temperature range is 0 to +50 °C, with a 115 % service factor for short-term overload capacity. Starting capacity is 3× Ie for 15 seconds.