A soft starter merely converts the power supply voltage, essentially a step-down starter. A soft starter is essentially a voltage regulator. When used to start a motor, the output only changes voltage, not frequency. A frequency converter, on the other hand, achieves this by changing the power supply frequency.
A frequency converter has all the features of a soft starter, but they are much more expensive and their structure is much more complex than a soft starter. A frequency converter is much more complex and expensive than a soft starter. A frequency converter also has soft-starting capabilities, but it does so by changing the power supply frequency.
First, soft starters and frequency converters have completely different purposes. A frequency converter is used where speed regulation is required, but its output not only changes voltage but also frequency. A soft starter is essentially a voltage regulator. When used to start a motor, its output only changes voltage, not frequency. A frequency converter has all the features of a soft starter, but it is much more expensive and its structure is much more complex.
Second, a soft starter only temporarily changes the power supply voltage, effectively acting as a step-down starter. However, frequency converters are significantly more complex and expensive than soft starters. Frequency converters also offer soft-start capabilities, both achieved by varying the power supply frequency.
Soft starters primarily utilize thyristors in the main circuit. They gradually increase the voltage by varying the thyristor conduction angle, ultimately achieving the starting process. This is the basic operating principle of a soft starter. However, while the low-voltage soft starter market is vast, high-voltage soft starters are relatively rare. While high-voltage and low-voltage soft starters share fundamentally the same principles, soft starters possess certain unique characteristics.
Frequency converters and soft starters are two different electrical devices, each with its own distinct functions and principles.
A frequency converter is an electrical device that controls the rotational speed of a motor. It can control both speed and output power by adjusting the output frequency. A soft starter is an electrical device that reduces starting current and torque when starting a motor. This reduces shock and vibration during startup for the motor and associated equipment, extending equipment life.
A frequency converter controls motor speed and output power by adjusting the output frequency, typically using PWM technology.
A soft starter reduces starting shock and vibration by controlling the current ramp rate and starting time, typically using circuits such as capacitors, resistors, and inductors.
Frequency converters are suitable for applications requiring motor speed regulation, such as motor control in machinery manufacturing, construction, pharmaceuticals, and food industries.
Soft starters are suitable for starting high-power motors, reducing starting current and torque, minimizing shock and vibration during startup, protecting equipment, and reducing energy consumption in industries such as metallurgy, petrochemicals, pumps, air compressors, and fans. Soft starters offer a simple structure, ease of maintenance, compact size, and convenient installation, all at a relatively competitive price.
Zhejiang Chuanken Electric Co., Ltd., a professional and experienced manufacturer of soft starters, has established a strong reputation in the industry thanks to its extensive technical expertise and innovative R&D capabilities.
Intelligent and convenient, multi-communication remote control, and durable design:
The 360 series soft starters feature an LCD screen with a simple interface and easy operation, supporting Chinese, English, and custom languages. They are compatible with Modbus 485 and Profibus protocols and support a mobile app for efficient remote debugging. The new DC contactor boasts 3x improved performance, 2.6x reduced heat generation, 25% enhanced safety, 20% energy savings, and a lifespan exceeding 100,000 cycles, ensuring stable equipment operation.
The following are the product parameters of 110kW Turkish Built in Bypass Soft Starter：
| Specifications | Overall dimension | Installation dimensions | ||||||
|---|---|---|---|---|---|---|---|---|
| W1 | H1 | D | W2 | H2 | H3 | D2 | ||
| 0.37–15KW | 55 | 162 | 157 | 45 | 138 | 151.5 | M4 | |
| 18.5–37KW | 105 | 250 | 160 | 80 | 236 | |||
| 45-75KW | 136 | 300 | 180 | 95 | 281 | M6 | ||
| 90–115KW | 210.5 | 390 | 215 | 160 | 372 |
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