Product Overview
The VD4 vacuum circuit breaker is a high-performance indoor medium-voltage switching device designed for air-insulated switchgear systems. It uses ABB vacuum interrupters, solid-sealed embedded epoxy poles, and a reliable CL stored-energy spring operating mechanism.
The breaker is suitable for switching and protecting electrical networks under both normal load conditions and fault conditions. It is designed for applications requiring high operational reliability, frequent switching, short-circuit interruption, and auto-reclosing duty.
VD4 circuit breakers are widely used in public utilities, industrial plants, transportation infrastructure, and construction projects. They are available as fixed installation units or as withdrawable units mounted on a chassis.
Product Features
Vacuum Interruption Technology
The VD4 uses ABB vacuum interrupters to provide reliable current interruption with fast dielectric recovery.
Key advantages include:
· Fast arc extinction at natural current zero
· High switching reliability
· Long electrical life
· Low maintenance requirements
· Suitable for frequent switching operations
· Suitable for expected short-circuit operations
Solid-Sealed Embedded Pole Design
The vacuum interrupter is embedded in cast resin epoxy poles, protecting it from external environmental influence.
Benefits include:
· Protection against impacts
· Protection against dust
· Protection against moisture
· Improved dielectric performance
· Compact column-type pole design
· Enhanced reliability in indoor switchgear applications
Reliable CL Spring Operating Mechanism
The VD4 is equipped with a CL stored-energy spring operating mechanism using a plane spiral spring.
Operating mechanism features include:
· Manual spring charging
· Motor-operated spring charging
· Electrical closing
· Manual closing
· Electrical opening
· Manual opening
· Fast operating times
· Opening spring charged during closing operation
Suitable for Auto-Reclosing
VD4 breakers are suitable for auto-reclosing duties and demanding switching cycles.
Supported operating sequences include:
· Standard rated operating sequence
· Auto-reclosing sequence
· Short-circuit operation sequence
Fixed and Withdrawable Configurations
The breaker is available in both fixed and withdrawable versions to meet different switchgear design requirements.
Configurations include:
· Individual unit for fixed installation
· Withdrawable breaker on chassis
· Control wiring plug for withdrawable versions
· Mechanical and electrical interlocks for withdrawable operation
Comprehensive Interlocking
The withdrawable version includes interlocking systems for operational safety.
Interlock features include:
· Prevention of moving the withdrawable part while breaker is closed
· Prevention of movement when earthing switch is closed
· Prevention of closing in intermediate positions
· Control plug connection only in test or disconnected position
Long Service Life
The VD4 is designed for long mechanical and electrical endurance with regular maintenance.
Service life data includes:
· Vacuum interrupter up to 30,000 switching cycles
· Operating mechanism up to 30,000 cycles
· Withdrawable assembly up to 1,000 movement operations
Main Functions
Medium-Voltage Circuit Switching
The VD4 performs switching operations in medium-voltage power networks.
Main switching functions include:
· Load current switching
· Fault current interruption
· Short-circuit breaking
· Circuit isolation in switchgear systems
· Switching of frequently operated networks
Protection During Fault Conditions
The breaker is designed to interrupt fault currents and protect downstream equipment and electrical installations.
Protection and interruption functions include:
· Short-circuit current breaking
· Short-circuit making capability
· Overcurrent trip operation when combined with relevant protection releases
· Auto-reclosing support for network continuity
Vacuum Arc Quenching
The vacuum interrupter extinguishes the arc at the first natural current zero. The vacuum interrupter pressure is maintained at approximately 10⁻⁴ to 10⁻⁸ mbar, enabling rapid dielectric recovery after interruption.
Stored-Energy Operation
The CL mechanism stores energy in a spiral spring for closing operation.
Operating functions include:
· Manual charging with charging lever
· Motor charging
· Closing by ON push-button
· Closing by shunt release ON
· Opening by OFF push-button
· Opening by shunt release OFF
· Opening by undervoltage release
· Opening by indirect overcurrent release
Remote and Local Control
VD4 supports local manual operation and electrical remote operation depending on installed auxiliary equipment.
Remote and local functions include:
· Manual ON / OFF operation
· Electrical ON release
· Electrical OFF release
· Second shunt release OFF for emergency breaking
· Undervoltage release
· Blocking magnet
· Anti-pumping relay
· Auxiliary switch signaling
Withdrawable Part Operation
Withdrawable VD4 breakers can be moved between positions using a hand crank or motor-driven system.
Withdrawable operation includes:
· Service position
· Test / disconnected position
· Manual insertion and withdrawal
· Motor-driven insertion and withdrawal
· Emergency manual operation if the motor fails
Anti-Pumping Function
The anti-pumping relay prevents repeated ON-OFF switching cycles if a permanent closing command remains present during or after a fault trip.
Vacuum Integrity Testing
Vacuum interrupter integrity can be tested without dismantling the breaker using a VIDAR tester.
Test voltages include:
· 40 kV DC for 12 kV and 17.5 kV breakers
· 60 kV DC for 24 kV breakers
Specifications
Fixed Installation Ratings, 12 kV and 17.5 kV
|
Breaker Type |
Rated Current |
Short-Circuit Breaking Current |
Short-Circuit Making Current, Peak |
Duration |
Pole Centres |
Weight |
| 1206-25 / 1706-25 | 630 A | 25 kA | 63 kA | 3 s | 150 / 210 mm | 85 / 90 kg |
| 1212-25 / 1712-25 | 1250 A | 25 kA | 63 kA | 3 s | 150 / 210 mm | 87 / 92 kg |
| 1216-25 / 1716-25 | 1600 A | 25 kA | 63 kA | 3 s | 210 / 275 mm | 177 / 177 kg |
| 1225-25 / 1725-25 | 2500 A | 25 kA | 63 kA | 3 s | 210 / 275 mm | 177 / 177 kg |
| 1231-25 / 1731-25 | 3150 A | 25 kA | 63 kA | 3 s | 275 mm | 177 kg |
| 1240-25 / 1740-25 | 4000 A* | 25 kA | 63 kA | 3 s | 275 mm | 177 kg |
| 1212-31 / 1712-31 | 1250 A | 31.5 kA | 80 kA | 3 s | 150 / 210 mm | 90 / 95 kg |
| 1225-31 / 1725-31 | 2500 A | 31.5 kA | 80 kA | 3 s | 210 / 275 mm | 177 / 177 kg |
| 1212-40 / 1712-40 | 1250 A | 40 kA | 100 kA | 3 s | 210 / 275 mm | 137 / 177 kg |
| 1225-50 / 1725-50 | 2500 A | 50 kA | 125 / 150 kA | 3 s | 275 mm | 177 kg |
| 1250-50 | 5000 A* | 50 kA | 125 / 150 kA | 3 s | 275 mm | 177 kg |
* 4000 A and 5000 A ratings require forced ventilation.
Fixed Installation Ratings, 24 kV
|
Breaker Type |
Rated Current |
Short-Circuit Breaking Current |
Making Current, Peak |
Duration |
Pole Centres |
Weight |
| 2406-25 | 630 A | 25 kA | 63 kA | 3 s | 210 / 275 mm | 140 / 140 kg |
| 2412-25 | 1250 A | 25 kA | 63 kA | 3 s | 210 / 275 mm | 140 / 140 kg |
| 2420-25 | 2000 A | 25 kA | 63 kA | 3 s | 275 mm | 160 kg |
| 2431-25 | 3150 A* | 25 kA | 63 kA | 3 s | 275 mm | 250 kg |
| 2412-31 | 1250 A | 31.5 kA | 80 kA | 3 s | 210 / 275 mm | 145 / 145 kg |
| 2431-31 | 3150 A* | 31.5 kA | 80 kA | 3 s | 275 mm | 255 kg |
