SSD series intelligent motor soft starter is a starting device produced by power electronic technology, microprocessor technology and modern control theory technology. This product can effectively limit the starting voltage of asynchronous motors when starting, and can be widely used in fans, pumps, Heavy-duty equipment such as conveyors and compressors are ideal replacement products for star/delta conversion, self-coupling pressure reduction, magnetic control pressure reduction and other step-down starting equipment.

working principle：

The main circuit of the SSD motor soft starter adopts six thyristors in anti-parallel connection and then serially connected to the stator circuit of the AC motor. Using the electronic switch function of the thyristor, the conduction angle of the thyristor is changed by the microprocessor controlling the change of its firing angle, thereby changing the size of the motor input voltage to achieve the purpose of controlling the soft start of the motor. When the start is completed, the soft starter output reaches the rated voltage. At this time, the three-phase bypass contactor KM is controlled to pull in, and the motor is put into power grid operation.

Voltage mode

Used to determine the initial torque of the motor (when the frequency is constant, the motor torque is proportional to the square of the applied voltage).
Setting range: 30%-80%. Need to consider current impact and mechanical impact when adjusting. If it is set too high, it may cause the initial current to be too large, the current impact and the mechanical impact are too high. In voltage mode, the current will vary according to the load, but the maximum value is limited to 5 times the rated current. The starting current can be reduced by increasing the starting time. When the load is light or no-load, the starting process will be completed even if the set rise time is not reached due to the accelerated establishment of the potential energy of the motor.

Current limit start

Determine the maximum current allowed by the motor during starting.
Setting range: 150-500% FLA (motor rated current) extension range, please consult the manufacturer. When the setting value is higher, the motor will draw a larger current from the main circuit and accelerate quickly. If the set value is too low, the motor will not reach full speed after the acceleration ends. Generally, it is better to set it to not stall. In order to make the starting current reach the limit quickly, the starting time should not be set too long.

Technical characteristics：

○ The parameter setting menu adopts tree-level management to facilitate the search and modification of the dynamic fault memory function, which is convenient to find the cause of the fault;

○ Comprehensive motor protection functions such as overcurrent, overheating, phase loss, and motor overload;

○ Comes with standard Modbus communication protocol;

○ Compact structure design, easy to install and easy to use;

○ The terminal adopts plug-in type, which is convenient for wiring;

○ Two-in-one driver board and main board, saving cost and convenient operation;

○ Executive standard: GB14048.6-2008 and IEC standard; 

Introduction of typical product applications:

SSD series intelligent motor soft starters are widely used in electric power, metallurgy, petroleum, petrochemical, mining, chemical, construction, building materials, municipal administration, military industry, light industry, textile printing and dyeing, paper making and pharmaceutical industries.

● Water pump—Using the soft stop function, the water hammer of the pump can be relieved when it stops, saving the cost of system maintenance.

● Ball mill—Using the voltage ramp to start, reduce the wear of gear torque and reduce the maintenance workload, which saves time and energy.

● Saved expenses. Fan-reduce belt wear and mechanical shock, saving maintenance costs.

● Compressor—Using current limitation, it realizes smooth starting, reduces motor heating and prolongs service life.

● Belt conveyor—a smooth and gradual starting process is realized through soft start, avoiding product displacement and liquid spillage.

Technical index:

● Main circuit working voltage: AC380 (+10%-15%);

● Main circuit working current: 40A-1200A;

● Main circuit frequency: 50Hz/60Hz (±2%);

● Control loop power supply: AC110V~240V(0.1A);

● Rise time of soft start: 1～120S;

● Soft parking time: 0～60S;

● Current limit multiple: 1.5～5.0le;

● Initial voltage: 30%～80% Ue;

● Cooling method: natural cooling;

● Communication method: RS485 serial communication;

● Number of starts ≤ 10 times/hour

Product model description：

Precautions for selection:

● The soft starter must provide a torque greater than the load resistance torque to complete the start. For ordinary loads such as water pumps, centrifugal pumps, etc. Single-start constant-load operation: If the cold state is 3 times the current limit, it is allowed to start for 40 seconds; when the current is 4 times the current, the maximum allowed is 25 seconds.
● When cycle start, start 10 times per hour, 3 times current allows 25 seconds to start, 4 times current allows 15 seconds. At this time, the thermal protection corresponds to level 10.
● For heavy loads such as ball mills and fans, 5 starts per hour are allowed. The current limit is as above, and the protection level is set to 20. If you increase the starting frequency, you should choose a product with a higher power grade. 

Application setting:

Product selection size：