Outdoor High Voltage Vcb

Product features

Extremely high reliability

Completely maintenance-free during the whole life.

High mechanical life and electrical life.

Small size, light weight and easy installation

 With standard relay protection and fast automatic reclosing function.

Using conditions of  ZW7-27.5  type Outdoor high voltage vcb

¨ Temperature：-30℃～60℃；

¨ Altitude：less than 2000m

¨ Wind speed :≤34m/s；

¨ Pollution Grade：Ⅳ级；

¨ Storage temperature：-40℃～85℃。

Main technical parameter of the vcb

Main mechanical parameter of breaker

Structure and working principle of circuit breaker

ZW7-27.5 Outdoor high voltage vcb is mainly composed of integrated sealed pole, current transformer, spring operating mechanism and box. This type of circuit breaker is miniaturized. At the same time, it is equipped with a manual emergency brake release device. Current transformer can be selected according to user's needs.

The control of ZW7-27.5 Outdoor high voltage vcb is completed by the intelligent control unit. The on-off operation of the switch can be realized locally, and it can also be operated remotely through the communication interface. Other information of the circuit breaker can also be transmitted to the control center, and the communication channel can be cable, optical fiber, GPRS/CDMA, GSM, etc.The control of ZW7-27.5 Outdoor high voltage vcb is completed by the intelligent control unit. The on-off operation of the switch can be realized locally, and it can also be operated remotely through the communication interface. Other information of the circuit breaker can also be transmitted to the control center, and the communication channel can be cable, optical fiber, GPRS/CDMA, GSM, etc.

The intelligent control unit is installed close to the circuit breaker and connected with the circuit breaker through a control cable. The power supply of intelligent control unit is divided into main power supply and standby power supply. The main power supply is AC or DC 220V, which is obtained by high-voltage line through PT. The backup power supply is provided by the battery (installed in the intelligent control unit box). When working normally, the main power supply charges the backup power supply; When the main power supply is lost, the backup power supply can still complete the control of the circuit breaker and other operations in the control unit. The backup power supply (when fully loaded) can keep the whole machine working for not less than 48 hours.

The operating mechanism of the circuit breaker is equipped with a manual emergency switch-off handle for emergency switch-off operation when the control system or power supply fails.

2.1 Working principle and process of circuit breaker

2.1.1 Arc extinguishing principle：

ZW37-27.5 Outdoor high voltage vcb adopts vacuum interrupter, with vacuum as arc extinguishing and insulating medium, which has extremely high vacuum degree. When the moving and static contacts are switched off with electricity under the action of the operating mechanism, 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 will also be generated in the gap between the contacts, which will promote the vacuum arc to remain diffuse, and make the arc evenly distributed on the contact surface to burn, so as to maintain a low arc voltage. When the current naturally crosses zero, the residual ions, electrons and metal vapor can be combined or condensed on the contact surface and the shield within microsecond order of time. Because the longitudinal magnetic field is used to control the vacuum arc, the vacuum circuit breaker has a strong and stable ability to break the current.

2.1.2 Storage：

The opening and closing energy of ZW7-27.5 Outdoor high voltage vcb is stored in high performance and installed in the box of intelligent controller unit. When opening and closing. Provided by the main power supply or backup power supply of the control unit, the charging time is not more than 10s, and the capacitor voltage error is ≤1V.。

2.1.3 Closing：Press the switch-on button on the intelligent control unit locally, or activate the switch-on coil of the operating mechanism by remote control switch-on operation, so that the iron core drives the moving contact of the circuit breaker to switch-on at the specified speed. When it is judged that the circuit breaker is in the closing position, the control loop automatically turns off the power supply of the closing coil. At this time, the iron core is kept at the closing side due to the action of the permanent magnet. After the closing coil is turned off, it can not only overcome the reaction force of the contact spring of the circuit breaker, but also have the closing self-holding force, so that the circuit breaker can be kept in the closing position reliably.

2.1.4 Opening：Press the switch-off button on the intelligent control unit locally, or activate the switch-off coil of the operating mechanism by remote control switch-off operation, so as to overcome the self-retaining force of the permanent magnet at the closing side and make the switch-off spring pull the iron core to drive the moving contact of the circuit breaker to switch-off at the specified speed. When it is judged that the circuit breaker is in the opening position, the control loop automatically turns off the power supply of the opening coil, and at this time, the iron core is kept at the opening side due to the pulling force of the opening spring, so that the circuit breaker is reliably kept in the opening position.

2.1.5 Manual emergency brake opening operation：

When the circuit breaker is in the closing position, hold down the manual switch-off operation button of the circuit breaker with an insulating operating rod and pull it down, and the circuit breaker can switch off at a certain speed, which can ensure that the circuit breaker can reliably switch off the rated load current.