Low-voltage circuit breaker, also known as automatic air switch, is a kind of circuit breaker that can not only connect and break the normal load current, but also realize the protection function when the circuit is overloaded, short-circuited and voltage-loss Switch electrical appliances. According to the structure, it is divided into two categories: frame type DW series (also known as universal type) and plastic case type DZ series (also known as device type). DW type and DZ automatic air circuit breaker

The main differences between the two are as follows:

1. In terms of structure, the DW type is a low-voltage frame type circuit breaker. All parts and components are installed in an insulated metal frame, which is often open, and the main accessories can be seen. DZ type is

Plastic case type automatic air circuit breaker, all parts are enclosed in a plastic case, it is a closed structure, compact structure, and good safety.

2. In terms of switching capacity, the DW type circuit breaker has a rated current of 200-6300A and a larger capacity. The maximum rated ultimate short-circuit breaking capacity is 135kA, while the DZ type circuit breaker is currently the largest

The rated current is 800A, and the maximum rated ultimate short-circuit breaking capacity is 100kA.

3. In the control mechanism, the DW type circuit breaker with a capacity of 6000A and below, in addition to manual operation, is also equipped with an electromagnetic closing operating mechanism, and 1000A and above are equipped with

Energy storage type and non-energy storage type motor closing operating mechanism. When using manual operation to close, the closing speed of the circuit breaker's contacts is related to the speed of the operation process. DZ circuit breaker

Mostly manual operation, large capacity can also be equipped with electric operating mechanism.

4. In terms of protection function, DW type has long time delay, short time delay and instantaneous three-stage protection and grounding protection. The setting value of each protection can be selected or adjusted within a certain range according to its shell frame level. The intelligent circuit breaker is equipped with a dedicated intelligent control module, which is more convenient for adjustment and testing, can fully guarantee the sensitivity and selectivity of the action, and can realize intelligent network monitoring, which is convenient for users to conduct integrated management.

DZ type also has three-stage protection characteristics, but due to space and price factors, thermal magnetic or electromagnetic tripping devices are mostly used, which has poor sensitivity and selectivity. The protection setting value has been set before leaving the factory, and most product users cannot adjust it by themselves. DZ type action trip time can be about 0.02s, faster than DW type.

5. In terms of installation form, DZ type is fixed type, while DW type can be divided into two types: fixed type and drawer type. 6. Compared with DZ-type circuit breaker in weight, the former is more than 2 times heavier than the latter.

7. In the configuration of accessories, DW type is equipped with overcurrent release, loss of voltage release, excitation release, auxiliary contacts and other accessories, and can be assembled at any time; while most of Dz type has no accessories, and some products are also available. There are undervoltage releases, shunt releases, terminals, etc., but they must be mentioned when ordering. It is inconvenient for general users to choose and install them. 8. On the occasion of use, DW type is mostly used for the main switch of low-voltage power distribution system, as well as the protection of important, heavy-loaded main lines, and can also be used for large-capacity motors that operate infrequently. DZ type is mainly used for terminal lines and some sub-trunk lines, mainly as electric motors and small-capacity lines