Big Pawer Electrical Technology Xiangyang Inc. Co., Ltd.

Overview: The MSS type soft starter integrates a thyristor assembly, bypass switch, and trigger control system, featuring a compact structure and complete soft-start functionality. The soft starter operates by controlling the thyristor firing angle to regulate the output voltage, meeting varying current and voltage requirements during motor startup. During startup, the soft starter gradually increases the motor's terminal voltage according to pre-set starting parameters, ensuring a smooth start and reducing electrical and mechanical impacts on the power grid and equipment. Once the motor reaches normal operating speed, the bypass switch closes, completing the startup process. Afterward, the upstream switchgear provides operational protection for the motor. This soft starter has a standard handcart structure, similar to a high-voltage vacuum circuit breaker. Combined with the KYN28 cabinet, it forms a high-voltage solid-state soft starter device integrating high-voltage switchgear distribution and soft-start functions, meeting various user requirements. Application Scope: The soft starter is primarily used for step-down soft starting of various large and medium-sized high-voltage motors. Scope of Application:  Voltage Range: 3-11kV;  Power Range: 200-3150kW;  Frequency: 50Hz/60Hz±2 Hz;  Phase Sequence: Operates under full phase sequence; Motor Type: Three-phase squirrel-cage asynchronous motor, and asynchronous starting synchronous motor. Operating Conditions: Normal Operating Conditions:  Ambient temperature: Upper limit not exceeding 40℃ (24-hour average temperature not exceeding 35℃), lower limit not lower than -5℃;  Relative humidity: Not exceeding 95%;  Altitude: Not exceeding 1000m;  Indoor installation, free from severe vibration and impact, and without fire or explosion hazards;  No conductive dust or corrosive gases present indoors. Special Operating Conditions: For the use of the soft starter under special conditions, the user and manufacturer should consult and reach a consensus. Common special operating conditions include:  Installation location exceeding 1000m altitude, where external insulation will be reduced. The manufacturer should be consulted to confirm whether the operating conditions are met. If not, equipment suitable for high-altitude use provided by the manufacturer can be selected.  When the ambient temperature is too high, the starter must be derated, the number of consecutive starts reduced, or a forced cooling system such as a fan installed.  Soft starters installed in high humidity or large temperature fluctuation conditions generally require the installation of preventative measures (such as heaters or cooling fans) to avoid condensation and malfunction. Technical Parameters Rated Voltage 3-11 kV Bypass Rated Current 250A, 400A, 630A Compatible Motor Current 0~200A Rated Operating Frequency 50HZ/60HZ±2HZ Phase Sequence Allowed to operate under any phase sequence Control Power Supply AC220V ±10% Operation Panel 480*272 Touch Screen Power Frequency Withstand Voltage 35kV (relative to ground) Cooling Method Forced Air Cooling Number of Starts ≤ 4 starts per hour at room temperature 25℃ and motor rated current below 100A, with a minimum start interval of 5 minutes; at room temperature above 25℃ or motor rated current above 100A, the number of starts per hour will decrease. Protections during startup include overcurrent protection, overvoltage protection, undervoltage protection, current imbalance protection, startup timeout protection, and bypass switch opening/closing fault detection. Starting methods include voltage ramp, constant current start, constant time, and sudden start. Soft start time is adjustable from 0 to 100 seconds, soft stop time is adjustable from 0 to 100 seconds, and initial/termination trigger angle is adjustable from 10 to 90 degrees (adjustment method is changing the trigger time). Current limiting multiple is adjustable from 50% to 500% Ie. Communication interface: RS485 communication interface, supporting Modbus protocol. Operating temperature: -5℃ to +40℃; Storage temperature: -20℃ to +50℃; Ambient humidity ≤95%, non-condensing; Altitude requirement ≤1000m. Structure: The soft starter includes a thyristor valve group, bypass switch, trigger control system, and is compatible with universal chassis and moving contacts. It connects to the switchgear using a primary connection with a perforated contact and connects to the switchgear's secondary circuit via a secondary aviation connector. Working Principle: The soft starter triggers the thyristor based on the detected voltage signal and preset parameters, gradually increasing the output voltage and thus gradually increasing the motor's terminal voltage. This allows the motor speed to gradually and smoothly increase to the rated speed. When the detected current drops to a certain level, it automatically switches to bypass operation, thereby achieving soft starting of the motor. Starting Protection Functions:  Overcurrent Protection: If a short circuit occurs in the line or the motor stalls, causing the current to exceed the set protection value, the system will issue a protection action and alarm.  Starting Timeout Protection: If the motor does not reach the bypass operation conditions within the set starting time, the system considers the start unsuccessful, issues a protection action, and alarms.  Current Imbalance Protection: During motor starting and operation, if the three-phase current imbalance exceeds the set protection value, the system will issue a protection action and alarm.  Starting Abnormal Protection: In ramp and constant current soft start modes, if no current greater than the rated current is detected within 5 seconds of starting, the system will issue a protection action and alarm.  Voltage Abnormal Protection: If the grid voltage exceeds the set protection value, the system will issue a protection action and alarm. System Measurement Functions:  Current Detection: A and C phase current;  Voltage Detection: A and C phase, voltage, frequency, and phase sequence of the mains input. Communication Interface and Switch Output Functions:  Communication Interface: Uses an RS485 serial interface, enabling start/stop control, uploading of operating status and parameters, and setting/modifying control parameters;  Switch Output: Uses intermediate relays to output external communication signals; all are passive contacts. Operation Interface:  Touch Screen: Color screen used for setting parameters, displaying status, and fault records; this screen is installed on the soft starter cabinet panel and works in conjunction with the selector switches, operation buttons, and indicator lights on the panel. Memory Function:  Program Memory: The DSP chip's program memory is an erasable and rewritable memory, allowing online programming for easy system upgrades; Power-Off Preservation Memory: Electrically Erasable Programmable Read-Only Memory (EEPROM) is used to save user-set parameters and fault information. Data is not lost after system power failure; parameters are re-downloaded from the EEPROM to the program memory each time the system is powered on. User Interface and Menus  Display Performance Parameters: Parameter Data Description Color 65K (65536) colors 16-bit color palette 5R6G5B Display Size 95mm (W) × 53.9mm (H) 480 × 272 pixels Backlight Mode 480 × 272 pixels Brightness LED Touch Method 4-wire resistive touchscreen