CD17-II Electromagnetic Operating Mechanism, Operating Mechanism for ZN28 and SN10 Switches

CD17A Electromagnetic Operating Mechanism

1. Overview The CD17A type is mainly suitable for matching with various fixed switchgear and ZN28A-12 split-type indoor high-voltage vacuum circuit breakers. This product uses DC power, and can perform electric closing and opening, manual opening, opening and automatic reclosing operations with indoor vacuum circuit breakers, and has a free trip function.

2. Technical Parameters

2. The coils of the mechanism are short-time duty, and their operating power supply is DC. 3. The reliable closing voltage of the mechanism is 85% to 110% of the rated operating voltage. The reliable opening voltage is 65% to 120% of the rated operating voltage, and the mechanism shall not open when the voltage is less than 30% of the rated operating voltage. 4. Between the conductive part and the grounding part, and between the conductive parts of different circuits. The 1-minute power frequency withstand voltage is 2000V, and there shall be no flashover or breakdown. The turns of the coil shall withstand 2.5 times the rated operating voltage. 5. The working angle of the output shaft of this mechanism is about 51°, and the service life of the mechanism is 10,000 times.

In the power system, high-voltage vacuum circuit breakers are key equipment to ensure the safe operation of the power grid, and the operating mechanism, as its core control unit, directly affects the opening and closing speed, reliability and service life of the circuit breaker. As a supporting component for outdoor high-voltage vacuum circuit breakers, the CD17 operating mechanism is widely used in switches such as ZW20, ZW7 and ZW32 models due to its stable design and flexible adaptability, and has become a common choice in power engineering.

3. Technical Principle and Structural Design:

The CD17 operating mechanism belongs to the spring energy-storage structure. Its core principle is to compress the spring for energy storage through a motor or manual mode. When receiving the opening and closing signals, the spring releases energy to drive the circuit breaker to act. This design avoids direct reliance on electromagnetic force, reduces the risk of coil burnout, and improves the action speed and consistency. The internal mechanism includes modules such as energy storage motor, cam connecting rod, opening and closing coils, and auxiliary switches. The opening coil voltage supports three specifications of 220V, 110V and 48V, and the closing coil voltage supports 220V and 110V, which can adapt to power distribution systems of different voltage levels.

This mechanism is mainly applied to outdoor high-voltage vacuum circuit breakers, covering distribution lines of 10kV-35kV voltage levels. Its adapted ZW20 series is suitable for overhead lines, the ZW7 series is commonly used for cable lines, and the ZW32 series is mostly used in urban and rural power grid transformation projects. Due to the modular design, the CD17 can quickly replace coils or adjust spring parameters to adapt to different environmental conditions such as altitude and temperature. For example, in cold regions, low-temperature grease can be replaced to ensure the reliability of the mechanism's action, and in humid environments, a sealing design can be used to prevent internal condensation.

Compared with traditional electromagnetic operating mechanisms, the spring energy-storage design of CD17 significantly reduces energy consumption. It only requires a short pulse current for a single opening and closing operation, and can save about 70% of electric energy during long-term operation. Its mechanical life reaches more than 10,000 times, far exceeding the 3,000 times standard of electromagnetic mechanisms, reducing maintenance frequency. In terms of opening and closing speed, CD17 can achieve an opening time of ≤50ms and a closing time of ≤80ms, meeting the requirements of the power system for rapid removal of short-circuit faults. In addition, the built-in auxiliary switch of the mechanism can provide multiple sets of contacts, which is convenient for linkage with automation devices to realize remote monitoring and fault diagnosis. Spring Operating Mechanism CD17/CT19/CTB Outdoor High Voltage Vacuum Circuit Breaker ZW20/ZW7/ZW32 Switch

During installation, it is necessary to ensure that the axis of the mechanism is aligned with the circuit breaker body to avoid part wear caused by lateral force. Regularly check the elastic coefficient of the energy storage spring, and replace it in time if the operating time is extended by more than 10%. As a vulnerable part, the opening and closing coils are recommended to be tested for insulation resistance every 3 years, and the cycle should be shortened in harsh environments. In areas where the voltage fluctuation exceeds ±15%, a voltage stabilizing device should be installed to prevent coil burnout. Daily maintenance only needs to clean the surface dust without disassembling the internal structure, which reduces the technical threshold for operation and maintenance.

Company Name: Yueqing Hengzhao Electric Co., Ltd.