ABB 1SF536268D1008: PSTX Control PCB, 100–250 V AC, Profibus DPV1 Ready, -25°C to +60°C

Technical Specifications

Main Features and Advantages

Thyristor phase-angle control + motor-protection in one PCBA:​ The core value of the ABB 1SF536268D1008​ is that it replaces the electromechanical “contactors + overload relay + separate soft-starter brick” stack with a single board that both fires the thyristors and decides when to trip. The ramp-profile algorithm (voltage ramp, current-limited ramp, torque-control ramp) is executed on the onboard microprocessor; the current feedback comes from the CT secondary (landed on the PSTX power-section terminals, read through the internal harness to the 1SF536268D1008); the protection logic (Class 10/20/30 overload, stall at 2–7× Ie, phase-loss, underload for pump run-dry) runs in the same scan. That integration means “soft start + motor protection + bypass contactor control” are one BOM line, not three.Torque control for pump applications:​ PSTX’s differentiator vs older PSS/PST generations is torque control — the ABB 1SF536268D1008​ runs a torque-estimation loop that flattens the pressure spike when a centrifugal pump transitions from ramping to constant-speed, preventing water-hammer. For municipal water lift stations, wastewater return-activated-sludge pumps, and irrigation booster sets, this is the feature that sells the PSTX (and by extension the 1SF536268D1008​ spare) — the board isn’t just “ramp voltage,” it’s “don’t break the pipe.”100–250 V AC wide-range control supply:​ The 1SF536268D1008​ accepts the full PSTX control-supply envelope (100–250 V AC, 50/60 Hz) and internally generates 24 V DC for logic. For a panel builder or a retrofit electrician, that means one spare fits control-transformers with either 120 V or 230 V secondary — no “oops, wrong tap” moments during an outage swap.FieldBusPlug comms slot:​ The motherboard carries a dedicated daughtercard socket for ABB’s FieldBusPlug modules — Modbus RTU (RJ45/terminals), Profibus DPV1, DeviceNet, and newer Ethernet/IP or Profinet builds depending on procurement window. The ABB 1SF536268D1008​ itself handles the PSTX-side protocol stack; the plug handles the physical layer and the master-side mapping. For plants where the PSTX talks up to ABB 800xA, Siemens PCS7, or Rockwell Logix, this slot is why the starter doesn’t need a separate gateway.Conformal coating for pump-station and mill duty:​ The PCB finish on the 1SF536268D1008​ is the same coated-boards standard ABB applies across PSTX (IP66 enclosure variants go to wash-down/food/marine). Conductive dust in a cement MCC room, condensation in a river-pump station intake building, salt aerosol in a desalination RO feed — the coating slows the creep that kills an uncoated control PCB in five years.DI/DO + keypad integration:​ 2–3 DI (Start, Stop, Select/Reset) and 2–3 relay outputs (Run, Fault, Bypass) are handled on the ABB 1SF536268D1008, along with the front-panel keypad/LCD ribbon. When a pump operator says “the Start button does nothing, but the PSTX has power,” the first suspect is the keypad ribbon; the second is the 1SF536268D1008​ itself. The relay outputs are 5 A class (typical, per PSTX BOM), enough for pilot-duty contactor shunt trips or annunciator horns, not for direct motor contactor coils — same discipline as the P3LG we covered earlier.Firmware-sensitive, PSTX-size matched:​ Like the P3LG, SAY130, and Relion boards in this ABB spare series, the ABB 1SF536268D1008​ is not “any PSTX spare fits any PSTX frame.” The R1008 label spans PSTX30 through PSTX1250, but the header pinout (DI/DO count, FieldBusPlug type, thyristor-gate harness connector) and the Flash image differentiate across frame sizes. Swapping blindly → “Internal Fault” or “Board Mismatch.” That makes the 1SF536268D1008​ a “matched spare per PSTX frame size” item — keep one for PSTX105, one for PSTX570, etc., not one generic bin.