ABB New VD4 Medium Voltage Vacuum Circuit Breaker

Overview of the new VD4 Medium Voltage Circuit Breaker

The new VD4 Medium Voltage Circuit Breaker is the perfect combination of vacuum interrupter design and manufacturing technology with resin-embedded pole plates and technical excellence in circuit breaker design, engineering and production.

The VD4 medium voltage circuit breaker uses vacuum interrupters embedded in resin pole plates.

Embedding the interrupters in resin poles makes the circuit breaker poles particularly robust and protects the interrupters from shock, dust build-up and moisture.

A vacuum interrupter consists of a contact and an interrupting chamber.

Vacuum interrupters Vacuum circuit breakers do not require an interrupting and insulating medium. In fact, the interrupter chamber contains no ionisable material.

In any case, the arc generated when the contacts separate consists entirely of melted and vapourised contact material.

The arc is supported by external energy until the current disappears near its natural zero point.

At this point, the load density decreases rapidly and the metal vapour condenses rapidly, leading to an extremely rapid recovery of the dielectric properties.

The vacuum interrupter thus regains its insulating capacity and its ability to withstand transient recovery voltages, and the arc is finally extinguished.

Due to the high dielectric strength achieved in a vacuum even at short distances, circuit interruption is guaranteed when the contacts separate a few milliseconds before the current passes through the natural zero point.

The special geometry of the contacts and the materials used, as well as the limited duration of the arc and the low voltage

guarantees minimum wear and a long service life of the contacts. In addition, the vacuum prevents oxidation and contamination of the contacts.

Operating mechanism type EL

The low speed of the contacts, the short running time and the low mass limit the energy required for operation and thus ensure extremely limited wear of the system. Circuit breakers

therefore require only limited maintenance.

VD4 circuit breakers have a mechanical operating mechanism with energy storage and free tripping. These features make opening and closing operations independent of the operator.

The operating mechanism is very simple to conceive and use, can be customised with various accessories and is quick and easy to install. This simplicity makes the equipment more reliable.

Structure

The operating mechanism and the magnetic poles are fixed to a metal frame which also serves as a support for the fixed circuit breakers.

The compact construction ensures robustness and mechanical reliability.

In addition to isolating contacts for connecting auxiliary circuits and flexible cables with plugs, the

The tractable circuit breakers are also equipped with a bracket trolley for putting them into or taking them out of the switchgear or enclosure with the door closed.

- Vacuum interrupter technology

- Vacuum contacts protect against oxidation and contamination

- Vacuum interrupters embedded in resin poles

- The interrupters are protected against vibration, dust and humidity.

- Poles sealed for life

- Operation in different climatic conditions

- Limited switching energy

- Energy storage operating mechanism with anti-pumping device as standard

- Simple customisation with a full range of accessories

- Fixed and withdrawable

- Compact dimensions

- Compact dimensions Robust and reliable

- Limited maintenance

- Doors closed when circuit breakers are racked in and out

- Special locks on the operating mechanism and forklift truck prevent incorrect and dangerous operation

- High environmental compatibility