ZW32-40.5M Outdoor High Voltage Permanent Magnet Vacuum Circuit Breaker (Manual Closing Function With Load)

Main technical parameters of circuit breaker

The ZW32-40.5M outdoor column permanent magnet solid-sealed vcb circuit breaker is mainly composed of a solid-sealed pole, current transformer, permanent magnet operating mechanism, and box body. This type of vcb circuit breaker is miniaturized and equipped with a manual emergency opening device. Current transformers can be adjusted according to customer needs. Compared with the conventional operating mechanism, the double mechanism with a load manual closing function is more flexible, reliable, and safe. The manual closing mechanism guarantees normal opening and closing in the absence of power supply or in case of smart control unit damage, and the reliability and mechanical life are further improved so that the operation mechanism is truly maintenance-free. The mechanism is also well-matched with the load characteristics of the medium voltage vacuum circuit breaker, enhancing operation quality and greatly improving the breaking performance of the circuit breaker.

The control system of the ZW32-40.5M vacuum circuit breaker outdoor model is completed by a set of smart control units. The switch can be opened and closed locally or remotely operated through the communication interface, and other information of the circuit breaker can also be transmitted to the control center. The communication channel can be cable, fiber, GPRS/CDMA, or GSM, etc.

The smart control unit is installed next to the vcb circuit breaker and connected via a control cable. Its power supply is divided into main and backup sources: the main power supply is AC or DC 220V obtained through the PT, while the backup is provided by a battery in the smart control unit box. During normal operation, the main power charges the backup; when the main power fails, the backup can maintain full control of the breaker and other operations for more than 48 hours. A manual emergency opening handle is also provided in the operating mechanism for power failure or control system emergencies.

1. Arc-extinguishing Principle: The ZW32-40.5M type outdoor column permanent magnet solid-sealed vacuum circuit breaker adopts a vacuum interrupter with vacuum as the arc extinguishing and insulating medium, characterized by extremely high vacuum levels. When the moving and static contacts open under the action of the operating mechanism while carrying current, a vacuum arc will be generated between the contacts. At the same time, due to the special structure of the contacts, an appropriate longitudinal magnetic field is generated in the gap of the contacts, which promotes the vacuum arc to remain in a diffusion type, and ensure the arc is evenly distributed on the surface of the contact to burn, maintaining a low arc voltage. When the current naturally crosses zero, the remaining ions, electrons and metal vapor can recombine or condense on the contact surface and the shield in the order of microseconds, quickly restoring the dielectric insulation strength across the interrupter gap, thereby extinguishing the arc to achieve the purpose of breaking the circuit. Due to the use of longitudinal magnetic field control over the vacuum arc, the vacuum circuit breaker has strong and stable breaking current capability.

2. Energy Storage: The ZW32-40.5M type outdoor column permanent magnet solid-sealed vacuum circuit breaker stores the energy required for opening and closing in a high-performance capacitor, which is installed in the intelligent controller unit box. During opening and closing operations, the energy is provided by the instantaneous discharge of the capacitor. The capacitor's charging energy is supplied by the main power supply or backup power supply of the control unit, with a charging time of no more than 10 seconds and a capacitor voltage error of no more than 1V.

3. Closing Operation: Locally pressing the closing button on the smart control unit, or remotely controlling the closing operation to activate the closing coil of the operating mechanism so that the iron core will dive the moving contact of the circuit breaker to close at the specified speed. Once the breaker is detected to be in the closing position, the control circuit automatically cuts off the power supply of the closing coil. At this time, due to the action of the permanent magnet, the iron core remains on the closing side. After the closing coil is de-energized, it can not only overcome the reaction force of the circuit breaker contact spring, but also has a self-holding force in the closing position, ensuring the circuit breaker reliably stays in the closing position.

4. Opening Operation: Locally pressing the opening button on the smart control unit, or remotely opening the door to activate the opening coil of the operating mechanism to overcome the self-holding force of the permanent magnet on the closing side. Once the breaker is detected to be in the opening position, the control circuit automatically cuts off the power supply of the opening coil. At this point, the iron core remains on the opening side due to the force of the opening spring, ensuring the circuit breaker reliably stays in the opening position.

Manual Emergency Opening Operation: When the circuit breaker is in the closing position, use an insulated operating rod to hook the pull ring on the manual opening handle of the circuit breaker and pull it downward. The circuit breaker will open and still maintain a certain opening speed, ensuring that the circuit breaker can reliably break the rated load current.