CD17-II electromagnetic operating mechanism, operating mechanism for ZN28 SN10 switches

CD17A Electromagnetic Operating Mechanism

I. Overview: The CD17A type is mainly applicable to matching with various fixed switchgears and ZN28A-12 separate indoor high-voltage vacuum circuit breakers. This product uses a DC power supply; when matched with an indoor vacuum circuit breaker, it can perform electric closing, manual opening, opening, and automatic reclosing operations, and has a free tripping function.

II. Technical Parameters

2. The mechanism's coil is for short-time duty, and its operating power supply is DC. 3. The reliable closing voltage of the mechanism is 85% to 110% of the rated working voltage. The reliable opening voltage is 65% to 120% of the rated working voltage; when it is less than 30% of the rated working voltage, the mechanism shall not open. 4. Between the conductive parts and the grounding parts, and between the conductive parts of different circuits, the power frequency withstand voltage for 1 minute is 2000V, with no flashover or breakdown. The coil can withstand 2.5 times the rated operating voltage between turns. 5. The working angle of the output shaft of this mechanism is approximately 51°, and the mechanism lifespan is 10,000 operations.

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

III. Technical Principles and Structural Design:

The CD17 operating mechanism belongs to a spring energy-storage structure. Its core principle is to compress the spring for energy storage via a motor or manually. When a closing/opening signal is received, the spring releases energy to drive the circuit breaker to operate. This design avoids direct reliance on electromagnetic force for driving, reducing the risk of coil burnout while improving operating speed and consistency. The mechanism internally includes modules such as an energy-storage motor, a cam linkage, an opening/closing coil, and an auxiliary switch. Among them, the opening coil supports three voltage specifications: 220V, 110V, and 48V; the closing coil supports 220V and 110V, which can adapt to distribution systems of different voltage levels.

This mechanism is mainly applied to outdoor high-voltage vacuum circuit breakers, covering distribution lines with voltage levels of 10kV to 35kV. The matched ZW20 series is suitable for overhead lines, the ZW7 series is often used for cable lines, and the ZW32 series is mostly used in urban and rural power grid transformation projects. Due to its 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 alpine regions, replacing low-temperature grease can ensure the operating reliability of the mechanism; in humid environments, the sealing design can prevent internal condensation.

Compared with traditional electromagnetic operating mechanisms, the CD17's spring energy-storage design significantly reduces energy consumption. A single opening/closing only requires a short pulse current, saving about 70% of electric energy in long-term operation. Its mechanical lifespan reaches over 10,000 operations, far exceeding the 3,000-operation standard for electromagnetic mechanisms, reducing maintenance frequency. In terms of opening/closing speed, the CD17 can achieve an opening time of ≤50ms and a closing time of ≤80ms, meeting the power system's requirements for rapid removal of short-circuit faults. In addition, the auxiliary switch built into the mechanism can provide multiple sets of contacts, facilitating 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, ensure the axis of the mechanism is aligned with the circuit breaker本体 axis to avoid part wear caused by lateral force. Regularly check the elastic coefficient of the energy-storage spring; if the operating time extends by more than 10%, replace it in time. The opening/closing coil is a vulnerable part; it is recommended to test its insulation resistance every 3 years, and shorten the cycle in harsh environments. In areas where voltage fluctuation exceeds ±15%, a voltage stabilizing device should be installed to prevent coil burnout. Daily maintenance only requires cleaning surface dust, without disassembling the internal structure, reducing the technical threshold for operation and maintenance.

Company Name: Yueqing City Hengzhao Electric Co., Ltd.