Description:
The ABB 1SFB536068D1011 is the main Control Motherboard / Drive Board (also called the thyristor firing and logic control PCB) for ABB PST and PSTB series low-voltage soft starters—most typically the PST105-600-70 and PSTB105 models (105 A rated). It functions as the “brain” of the soft starter: it processes start/stop commands from the local keypad or external PLC, calculates the optimal thyristor (SCR) firing angle in real time to produce a smooth voltage ramp, monitors motor current/voltage for protective functions (overload, phase loss, stall, over-temperature), and supports optional FieldBusPlug communication modules for integration into plant DCS or SCADA networks.
Application Scenarios:
Imagine a municipal water pumping station where a 55 kW centrifugal pump is started direct-on-line, causing repeated water-hammer damage to check valves and excessive inrush current that occasionally trips the upstream MCC feeder. The station already has an ABB PST105 soft starter installed, but after 12 years of service the internal control board begins showing random “Control Fault” or blank display symptoms—a classic sign of aged electrolytic capacitors or logic section degradation on the ABB 1SFB536068D1011. The maintenance crew powers down the starter, removes the two securing screws, unplugs the ribbon cable and keypad header, and installs a new 1SFB536068D1011. Upon power-up, the original start/stop ramp parameters are already retained in the non-volatile memory (or can be quickly re-entered from the panel). The pump now accelerates smoothly over the programmed 10-second ramp, inrush current drops from 6×FLC to <2.5×FLC, and water-hammer is eliminated—extending valve and pipe life while keeping the MCC stable during simultaneous starts elsewhere in the plant.
Parameter:
| Main Parameters | Value/Description |
|---|---|
| Product Model | 1SFB536068D1011 |
| Manufacturer | ABB (ABB Drives / Motion Control) |
| Product Category | Soft Starter Control Motherboard / Drive Board (PCB Assembly) |
| Compatible Series | ABB PST & PSTB Series Low-Voltage Soft Starters |
| Typical Fits | PST105-600-70, PSTB105 (105 A rated, ~45–75 kW depending on voltage) |
| Control Supply Voltage | 100 – 250 V AC (50/60 Hz), derived from soft starter internal auxiliary supply |
| Main Circuit Compatibility | 200 – 690 V AC 3-phase (thyristor firing pulses optically isolated) |
| Microcontroller / Logic | Onboard MCU executing voltage-ramp / current-limit algorithms + motor protection logic |
| Thyristor Trigger Output | Optically isolated gate-pulse trains to main power thyristors (SCR firing angle control) |
| Communication | Local keypad port + FieldBusPlug slot (supports Modbus RTU, Profibus DP, DeviceNet via plug-in module) |
| Protection Functions | Motor overload (I²t), phase loss/unbalance, start-time-overrun, stall, over-temperature, underload |
| Operating Temperature | 0 °C to +55 °C (cabinet internal ambient; storage –25 °C to +70 °C) |
| Mounting Method | Internal card-slot / standoff mount inside soft starter enclosure; secured by screws & ribbon header |
| Dimensions (approx.) | 150 × 115 × 30 mm (H × W × D), Weight ≈ 0.25–0.35 kg |
| Certifications | CE, UL, cUL, compliant with IEC 60947-4-2 |
Technical Principles and Innovative Values:
- Innovation Point 1: Dual-Mode Start Control with Real-Time SCR Angle Computation. The ABB 1SFB536068D1011 implements both voltage-ramp and current-limited start algorithms in firmware, continuously adjusting the thyristor firing delay (α-angle) on each half-cycle to track the target curve—even under varying line voltage—ensuring repeatable soft-start performance that generic timer-relay solutions cannot match.
- Innovation Point 2: Integrated I²t Motor Thermal Model & Phase-Failure Detection. Unlike basic start-modules that only pass gate pulses, the 1SFB536068D1011 models motor heating via accumulated I²t, compares measured phase currents for imbalance/loss, and initiates a controlled trip before insulation damage occurs—adding a layer of motor protection without external thermal relays.
- Innovation Point 3: Fieldbus-Ready Architecture with Local Keypad Bypass. The board reserves a FieldBusPlug socket for snap-in communication modules, allowing the soft starter to report run-status, current, fault-code, and accept remote start/stop from a DCS. Simultaneously, a local LCD keypad connects directly to the ABB 1SFB536068D1011, enabling commissioning and emergency operation independent of the network—a critical fail-safe in plants where comms may be temporarily down.
