Yantai Bonway Manufacturer

IEC indoor vacuum circuit breaker VD4
Superior performance for protection
Maximize your productivity with reduced downtimes with ABB’s flagship product family of VD4 circuit breakers for primary and secondary protection, with a global installed base of over 2 million units and higher performance than the market standard. Protect your assets with an optimum interface, utilizing the market’s widest portfolio of circuit breakers, covering global standards and ratings fitting your specific needs.
Product scope
Medium voltage circuit breakers with mechanical actuator (spring mechanism) for primary distribution up to 46 kV, 4000 A, 63 kA.
Key benefits
The most versatile and powerful solution among medium voltage vacuum circuit breakers
Ideal for all applications (eg, capacitor bank switching, marine, GOST)
More than 2 million VD4 medium voltage vacuum circuit breaker installed worldwide
Cassettes and module systems available for OEMs and panel builders to create their own solutions
Fully interchangeable — both for overall dimension and electrical diagram — with ABB VD4 medium voltage gas circuit breaker
Only one common plug-and-play actuator (EL type) from 12 kV to 36 kV with a wide range of accessories, safety locks and interlocks, and with same family feeling of ABB low voltage series EMAX
Key features
Vacuum interrupters embedded in poles for protection against humidity, shocks and dust
Modular spring-operated mechanical actuator ensuring easy operation even without auxiliary supply
30,000 mechanical operations on most ratings
Rated at up to 46 kV, 4000 A, 63 kA.

General
The VD4 are a synthesis of the renowned technology in designing and constructing vacuum interrupters embedded in resin poles, and of excellency in design, engineering and production of medium voltage circuit-breakers.
Embedding the interrupter in resin makes the circuit-breaker poles particularly sturdy and protects the interrupter against shocks, accumulation of dust and humidity.
The vacuum interrupter houses the contacts and makes up the interrupting chamber.
Current interruption in vacuum. The vacuum circuit-breaker does not require an interrupting and insulating medium. In fact, the interrupters do not contain ionisable material.
In any case, on separation of the contacts an electric arc is generated made up exclusively of melted and vaporised contact material.

The electric arc remains supported by the external energy until the current is cancelled in the vicinity of natural zero. At that instant, the rapid reduction in the load density carried and the rapid condensation of the metallic vapour, leads to extremely rapid recovery of the dielectric characteristics.
The vacuum interrupter therefore recovers the insulating capacity and the capacity to withstand the transient recovery voltage, definitively extinguishing the arc.
Since high dielectric strength can be reached in the vacuum, even with minimum distances, interruption of the circuit is also guaranteed when separation of the contacts takes place a few milliseconds before passage of the current through natural zero.

The special geometry of the contacts and the material used, as well as the limited duration and low voltage of the arc, guarantee minimum contact wear and long life. Furthermore, the vacuum prevents their oxidation and contamination.
Operating mechanism
The low speed of the contacts, together with the reduced run and low mass, limit the energy required for the operation and therefore guarantee extremely limited wear of the system. The circuitbreaker therefore only requires limited maintenance.
The VD4 circuit-breakers use a mechanical operating mechanism, with stored energy and free trip. These characteristics allow opening and closing operations independent of the operator.

The structure
The operating mechanism and the poles are fixed to a metal frame which is also the support for the fixed version of the circuit-breaker. The compact structure ensures sturdiness and mechanical reliability.
Apart from the isolating contacts and the cord with plug for connection of the auxiliary circuits, the withdrawable version is completed with the truck for racking it into and out of the switchgear or enclosure with the door closed.

In a vacuum interrupter, the electric arc starts at the moment of contact separation and is maintained until zero current and can be influenced by magnetic fields.
Vacuum arc – diffuse or contracted
Following contact separation, single melting points form over the entire surface of the cathode, producing metal vapours which support the arc.
The diffuse vacuum arc is characterised by expansion over the contact surface and by an even distribution of thermal stress on the contact surfaces.
At the rated current of the vacuum interrupter, the electric arc is always of the diffuse type.
Contact erosion is very limited and the number of current interruptions very high.
As the interrupted current value increases (above the rated value), the electric arc tends to be transformed from the diffuse into the contracted type, due to the Hall effect.
Starting at the anode, the arc contracts and as the current rises further it tends to become
sharply defined. Near the area involved there is an increase in temperature with consequent thermal stress on the contact.
To prevent overheating and erosion of the contacts, the arc is kept rotating. With arc rotation it becomes similar to a moving conductor which the current passes through.
The spiral geometry of ABB vacuum interrupter contacts
The special geometry of the spiral contacts generates a radial magnetic field in all areas of the arc column, concentrated over the contact circumferences.

An electromagnetic force is self-generated and this acts tangentially, causing rapid arc rotation around the contact axis.
This means the arc is forced to rotate and to involve a wider surface than that of a fixed contracted arc.
Apart from minimising thermal stress on the contacts, all this makes contact erosion negligible and, above all, allows the interruption process to be controlled even with very high short-circuits.
ABB vacuum interrupters are zero-current interrupters and are free of any re-striking.
Rapid reduction in the current charge and rapid condensation of the metal vapours simultaneously with the zero current, allows maximum dielectric strength to be restored between the interrupter contacts within microseconds.

Versions available
The VD4 circuit-breakers are available in the fixed and withdrawable version with front operating mechanism.
The withdrawable version is available for UniGear ZS1/ZS3.2 and ZS8.4 type switchgear, PowerCube and Powerbloc modules.
Fields of application
The VD4 circuit-breakers are used in power distribution for control and protection of cables, overhead lines, transformer and distribution substations, motors, transformers, generators and capacitor banks.

Standards and approvals
The VD4 circuit-breakers comply with the IEC 62271- 100, VDE 0671 part 100, CEI 17-1 file 1375
Standards and with those of the major industrialised countries.
The VD4 circuit-breakers have undergone the tests indicated below and guarantee the safety and reliability of the apparatus in service in any installation.
• Type tests: temperature rise, withstand insulation at power frequency, withstand insulation at lightning impulse, short-time and peak withstand current, mechanical life, short-circuit current making and breaking capacity, and no-load cable interruption.

• Individual tests: insulation of the main circuits with voltage at power frequency, auxiliary circuit and operating mechanism insulation, measurement of the main circuit resistance, mechanical and electrical operation.
Service safety
Thanks to the complete range of mechanical and electrical locks, it is possible to construct safe distribution switchgear with the VD4 circuitbreakers.

The locking devices have been studied to prevent incorrect operations and to inspect the installations whilst guaranteeing maximum operator safety.

Accessories
The VD4 circuit-breakers have a complete range of accessories to satisfy all installation requirements.
The operating mechanism has a standardised range of accessories and spare parts which are easy to identify and order.
The accessories are installed conveniently from the front of the circuit-breaker. Electrical connection is carried out with plug-socket connectors.
Use, maintenance and service of the apparatus are simple and require limited use of resources.
Operating mechanism
The operating mechanism is of the stored-energy spring type and acts on the three breaker poles. The necessary operating energy is stored ready for activation by charging the spring energy store.
The stored-energy spring mechanism essentially consists of drum containing the spiral spring, the charging system, the latching and operating mechanism and the linkages which transmit the force to the breaker poles. In addition, there are supplementary components such as the charging motor, releases, auxiliary switches and the controls and instruments located on the front of the mechanism enclosure.
The operating mechanism is fundamentally suitable for auto-reclosing and, due to the short charging times, also for multi-shot auto-reclosing.
The generator breaker have a built-in mechanical delay system with which the opening time is prolonged by approx. 30 ms.
In the basic version of the circuit-breaker, the spring energy store is charged manually. The operating mechanism can optionally be fitted with a charging motor.

The shunt release ON is used for remote controlled closing of the circuitbreaker. Auxiliary switch BS1( S1) enables the release when the spring is charged. Auxiliary switch BB1( S3) is used for disconnection. Both are necessary and are included in the scope of supply. The release is optional on breakers with manual operating mechanisms and included in the scope of supply for breakers with charging motors.
The scope of supply for the closing release also includes antipumping relay -K0. The antipumping relay prevents repeated closing and opening cycles when, for example, the circuit-breaker is tripped by a protection relay in response to a primary circuit fault and a permanent electrical closing command is active at the same time. Closing of the circuit-breaker is then only enabled again when the active closing command has been interrupted.

When de-energized, the blocking magnet prevents closing of the circuitbreaker. A voltage must be applied to the blocking magnet for at least 100 ms in advance of the closing command. Auxiliary switch -BL1(-S2) is necessary and included in the scope of supply.