China Soft Starter Factory Direct

Soft Starters represent a major product category that Yibaling, as a professional manufacturer of electrical equipment, offers to global buyers. In addition, we also offer products such as automatic voltage regulators and various transformers, which you can customize according to the actual needs of your project.

Company Profile

Zhejiang Yibaling Power Equipment Co., Ltd. is a professional supplier of Soft Starters and many other types of products.
Our products comply with the national compulsory product certification (CCC), the EU CE safety certification, and the ISO9001 quality management system certification standards.
In addition, we have over 3 years of experience in manufacturing for export. Yibaling transformers enjoy a warranty period of at least 2 years.
Yibaling's factory has over 10 engineers and technicians and a staff of over 60 people.

Why Choose Us？

1. High Quality

Our Yibaling factory is renowned for its diverse product lines and strict quality control throughout the entire process (from the selection of raw materials to the meticulous production procedures and to the delivery of high-quality products).

2. Professional Team

Our company also has a professional team consisting of over 10 engineers and technical personnel, as well as a basic force of over 60 employees, which can cover every aspect from design to production and delivery. We are committed to providing customized services that fully meet your unique requirements for our clients.

3. Support ODM/OEM

We fully support the in-depth cooperation between ODM and OEM. Whether you need to brand standard products that are compatible with existing systems, or conduct new design and development from concept to finished product, our professional team can work closely with you.

What is a soft starter?

A soft starter is a device specifically designed to control large-capacity AC motors to achieve smooth startup and shutdown.
Its core principle is to precisely regulate the voltage applied to the motor during the critical stages of startup and shutdown using thyristors (thyristors). This solves the problem of excessive current and mechanical shock during direct startup.
During startup, it controls the voltage to start from a lower value (such as 30% of the rated voltage) and smoothly rise to full voltage within a set time, limiting the startup current to 1.5-4 times the rated current, and allowing the speed to rise smoothly. Once the full speed is reached, the internal bypass contactor engages, and the motor operates directly from the power grid.
During shutdown, it can also control the voltage to gradually decrease, achieving "soft shutdown" to prevent water hammer in pumps, conveyor belt slippage, and other shock problems.
The soft starter is like the "slow ramp start and smooth braking system" for the motor. It does not change the operating speed but focuses solely on optimizing the smoothness of the startup and shutdown process to protect the motor, transmission machinery, and the power grid.
Its structure is simpler and costs less than a frequency converter, making it an economical and reliable startup solution for heavy equipment such as fans, pumps, and compressors in scenarios where speed adjustment is not required.
They are essentially “intelligent buffers” and “system guardians” designed specifically for AC motors. Their core function is to completely resolve the two persistent issues caused by direct motor starts: 5-7 times the impact current and severe mechanical stress. By controlling the conduction angle of thyristors, it enables ramped soft starts—smoothly increasing voltage and torque from a preset low point to full voltage.

How does a soft starter work?

The working principle is to use the phase angle control technology of the thyristor (thyristor) to smoothly adjust the input voltage during the motor startup and shutdown stages, thereby limiting the starting current and reducing mechanical shock. Its working process is divided into three stages:
During startup, the microprocessor controls the conduction angles of three groups of series-connected thyristors to start the output voltage from a preset lower value (such as 30% of the rated voltage), which then rises linearly to full voltage within the set time.
The motor torque and speed increase steadily, and the startup current is limited to 1.5-4 times the rated current. Once the rated speed is reached, the internal bypass contactor engages, and the current is directly conducted, avoiding continuous power loss of the thyristors.
When stopping (if a soft stop is required), the thyristors are re-engaged, and the voltage is smoothly reduced from full voltage to zero, achieving a smooth deceleration of the speed, effectively preventing mechanical shocks such as water hammer and belt slippage.
The soft starter is a "electronic slope controller" specifically designed for motors. It does not change the operating frequency and speed, but instead precisely regulates the voltage slope during the start-up and stop phases, exchanging the hard protection of the mechanical system for the soft electrical characteristics, and is a cost-effective solution for addressing the start-up and stop shock problems of high-power motors.