Function and selection of accessories of moulded case circuit breaker
The accessories of moulded case circuit breaker are divided into two types: internal accessories and external accessories. The internal accessories are the accessories installed in the circuit breaker body, including four internal accessories: shunt release, undervoltage release, auxiliary switch and alarm switch. The external accessories are the accessories installed outside the circuit breaker, which also includes the auxiliary devices Auxiliary handle, external operation handle, electric operation mechanism, mechanical interlocking device, electric interlocking device and other external accessories.
When we use the circuit breaker, if the voltage is not enough, we need the help of the undervoltage release, which is also a highly protective accessory. When our power supply voltage drops to 35-70% of the rated voltage of the undervoltage release, the undervoltage release will make the circuit breaker trip. If the power supply voltage is lower than the undervoltage release, the undervoltage release will make the circuit breaker trip When the rated voltage of the voltage release is 35%, the undervoltage release can ensure that the circuit breaker will not be closed, but the rated voltage will make the circuit breaker work normally continuously if it is more than 85%.
The auxiliary handle is generally used on the large capacity circuit breaker with the capacity of 600 a and over. It allows us to manually separate the gate or manually merge the gate. The external handle has an external accessory which can convert the up and down moving operation of the circuit breaker into the rotating operation function.
The handle locking device is a kind of protection device that can make the handle of the circuit breaker operate reliably above the opening or closing position and will not affect the free tripping of the circuit breaker in the slightest. The mechanical interlocking device is also a special protection device, which is mainly used in the circuit with dual power supply. The two circuit breakers can not be at the same time This device can be used perfectly when the power is on. The electrical interlock device is also known as the automatic power switching device. It can perfectly realize the automatic and ring double power protection device.
In addition to the most common wiring mode, the wiring mode behind the board and plug-in wiring mode are very special. For example, the wiring mode behind the board needs to use the rear wiring device. If it is plug-in, we need to use plug-in installation platform.
The electric operation mechanism is not only a kind of circuit breaker external accessories for remote operation, but also a kind of general large-scale switch which is often used for on-site operation of switches more than 630A. The installation mode of molded case circuit breaker is very different from the wiring mode. According to the installation mode, it is divided into fixed type and applicable to that drawer cabinet There is also a design of plug-in or pull-out type, which is suitable for use in the environment like fixed cabinet. If we divide it according to the wiring method, whether it is fixed type, plug-in type or pull-out type, there are different products with wiring in front of the board and wiring in back of the board. Some products also have professional and special cable or bus front or rear connection Of a wire terminal.
