ABB PSTX370-600-70

The **PSTX370-600-70** is a **high-power, high-performance softstarter** from ABB's **PS300** series. Its core function is to **control the smooth starting and stopping of three-phase AC asynchronous motors** by automatically controlling its output voltage, effectively reducing the starting current and minimizing impact on the power grid and mechanical transmission systems.
You can think of it as an intelligent "motor acceleration and deceleration controller" specifically designed for safely starting and stopping large industrial motors.
### Detailed Functional Introduction and Features
1.  **Smooth Starting and Stopping**:
    *   **Starting**: Achieves smooth motor acceleration by gradually increasing the voltage and torque applied to the motor (adjustable ramp time) until it reaches full speed. This avoids the huge inrush current typical of direct-on-line starting (usually 5-8 times the rated current).
    *   **Stopping**: Can also provide a smooth deceleration stop function (optional), reducing the "water hammer" effect (in pump applications) or mechanical vibration.
2.  **Reduced Impact**:
    *   **Grid Impact**: Significantly reduces the starting current (can typically be limited to 2-4 times the rated current), preventing grid voltage dips and avoiding interference with other equipment on the same network.
    *   **Mechanical Impact**: Reduces stress and wear on mechanical transmission components such as gears, couplings, belts, and pump impellers, extending equipment service life.
3.  **Built-in Protection Functions**: Provides comprehensive motor protection to ensure operational safety:
    *   Overload protection
    *   Phase loss protection
    *   Current imbalance protection
    *   Start timeout protection
    *   Overheating protection (via direct motor temperature monitoring with PTC thermistors)
    *   Stall protection
4.  **Multiple Control Modes**:
    *   **Voltage Ramp Start**: The most common mode, with linear voltage increase.
    *   **Torque Control Start**: Provides smoother starting, especially suitable for heavy-duty starting applications like conveyors and crushers.
    *   **Pump Control**: Optimized for pump loads, providing smooth starting and stopping to completely eliminate water hammer.
    *   **Direct Start**: Can be bypassed for direct starting mode when needed.
5.  **Intuitive Setup and Monitoring**:
    *   Integrated display with LED status indicators.
    *   Easy setting of start parameters, protection thresholds, and viewing of operational data (e.g., motor current) via knobs and buttons on the panel.
6.  **Compact and Integrated Design**: Compared to frequency converters, softstarters have a simpler structure and lower cost. The **PSTX370** series integrates the bypass contactor internally. After motor start-up, it switches from the internal thyristors to the internal bypass contactor for operation, thereby reducing its own power consumption and heat generation, improving efficiency.
### Key Technical Data and Parameters
*   **Product Family**: ABB PS300 series softstarter
*   **Rated Current**: **370 Amps** - This is its most critical performance parameter, meaning it is suitable for motors with a rated current not exceeding 370A.
*   **Rated Voltage**: **600 Volts** (corresponds to 480VAC motor systems)
*   **Motor Power**: Suitable for motors approximately in the range of **200 HP (150 kW) to 600 HP (450 kW)** (exact selection requires precise calculation based on voltage and motor rated current).
*   **Control Supply**: Typically **100-250V AC/DC** (wide-range supply for greater adaptability).
*   **Protection Rating**: Typically **IP00 / IP20**, meaning it must be installed inside a protective electrical control cabinet to prevent dust and moisture ingress.
*   **Core Technology**: Uses **thyristor (SCR)** technology to regulate output voltage.
### Typical Application Scenarios
This high-power softstarter is widely used in industrial fields that require controlling the starting impact of medium to large-power motors:
*   **Water Pumping Stations**: Large centrifugal pumps, feedwater pumps, booster pumps, to eliminate water hammer.
*   **Fans**: Large centrifugal fans, induced draft fans, supply fans.
*   **Compressors**: Air compressors, gas compressors.
*   **Conveying Systems**: Long-distance, heavy-duty belt conveyors.
*   **Crushers and Mills**: Heavy machinery like ball mills, crushers.
### Important Considerations
1.  **Not a Speed Control Device**: The main purpose of a softstarter is to **control the start/stop process**, not to **continuously adjust the motor speed** during operation like a Variable Frequency Drive (VFD). If speed control is required, a VFD should be selected.
2.  **External Protection Required**: Although this model has an **integrated internal bypass contactor**, external circuit breakers or fuses are still required to provide short-circuit protection.
3.  **Cooling Requirements**: Heat is generated during the starting process. It must be installed in a well-ventilated control cabinet, following the installation clearances specified in the manual.
4.  **Selection Basis**: The core basis for selection is the **motor's rated current** and **rated voltage**, not the motor's power (kW or HP). The motor's Full Load Amperage (FLA) must be less than or equal to the softstarter's rated current.
### Summary
The **ABB PSTX370-600-70** is a powerful and reliable 370A high-current softstarter. It is an ideal solution for protecting the power grid, the motor, and mechanical equipment from the impact of direct starting. Its integrated bypass contactor design improves energy efficiency and simplifies external wiring, making it a common choice for medium to high-power motor applications such as pumps, fans, and compressors.
If you have a large motor with a rated current around 370A that requires smooth starting, this product is a very suitable candidate. If you need this product, feel free to contact us!