Air Circuit Breaker

Application Scope

    The rated power of DW45 Series Air Circuit Breaker (referred to as circuit breaker hereinafter)is a kind of breaker with AC 50Hz,400V,or 690V,and its rated current is 400-6300A.It is mainly used in power distribution network to allocate electric power and protect the line and supply equipment against overload,under voltage,short circuit,single phase grounding fault,etc.The core part of the circuit breaker adopts intelligent type dropout device,which bears accurate alternative protection performance and can avoid unnecessary power failure,thus improve the reliability of power supply.

Structure Character

    The product has two types of structure,namely,fixed type,which is mainly composed of contactor part,intelligent drop-out device,manual operation mechanism,electric operation mechanism,electric operation mechanism and drawer base.

    The circuit breaker is placed in three-D pattern and is characterized by its tight structure and small volume.The contactor part is sealed in the insulation bottom plate,and contactors of every phase are separated with insulation board,hence several little chambers;while the intelligent dropout device,the manual-operation mechanism,and the electric operation mechanism are arranged before it in good order and form independent unit respectively.In case one of the units is damaged,it can be dismounted wholly to fix a new one.Among which:

    1.Contactor part:AS one-step contactor is adopted,operating strength of the contactor is reduced because of the omitting of arc contactor transfer process,and the breaking process of short-circuit current is therefore accelerated.In order to reduce the electric repelling force among contactors and improve the electric stability of the contactor part,the contactor part adopts multi-way parallel connection.Welding connects the contactor,soft joint and bus bar,seeing that it can reduce contact resistance and decrease power consumption.

    2.Arc extinguish chamber:the wall of arc extinguish chamber is made of compressed insulation material,and arc extinguish fence is mounted in the chamber to enable the electric arc blow upward into the chamber.

    3.Base:contactor and arc extinguish system are both placed between the upper and lower base,which are made of compressed insulation materials with high intensity and excellent electric performance.Every phase is designed into independent small chamber,and the contactor is mounted on the insulation support,thus short circuit among phases is not likely to happen,and the gas generated when breaking the short-circuit current won't eject downward.The design can ensure reliable breaking when wire is lowery input.

    4.Operation mechanism:Operation mechanism is made of two types,manual operation type and dynamo-driven type,which are both fixed on the insulation base and are at are at front side of the circuit breaker.The operation mechanism adopts free drop-out mechanism that changes four-pole into five-pole.To meet the requirement of auto control,the mechanism is designed into the type  of presorted energy.In the operation of the circuit breaker,the mechanism is always in the state and position of presorted energy,and once closing order is received,the circuit breaker can close instantly.Release the mechanism is always in the state and position of presorted energy,and once closing order is received,the circuit breaker can close instantly. Release of the pressorted energy can be performed with manual-releasing button or releasing electromagnet, and remote control may also be adopted.

   5. Functions of intelligent type drop-out device are as follows:(1)protection against overload long time-relay counter time limit, short time-relay counter time limit, and instant operation, etc; it can be set by users according to practical requirement; (2)Protection against grounding fault; (3)overload alarm; (4)testing; (5)load monitor; (6)display; (7)auto checkout; (8)MCR function; (9)thermo-analogue; (10)contactor wear indication; (11)fault record; (12)intelligent dropout device has L type(economic type), M type(ordinary type),and H type(with communication port type).