Product Overview
High-Current Indoor Vacuum Circuit Breaker from a Reliable Manufacturer and Factory Supplier
The VS1 series indoor lateral vacuum circuit breaker was made for high-current MV applications with its maximum rating of 12kV and continuous current of 4000A, with a short-circuit breaking capacity of 31.5kA. Vacuum arc extinguishing enables clean and easy interruptions, while lateral-type design ensures its use in high-current switchgears.

Applications & circuit protection
The VS1 4000A is used in scenarios where high steady-state currents and excellent fault protection combine – generally for large feeders, factories and switchgear units.
- High current feeders: protection against large MV feeders.
- Industrial plants: protection of circuits for heavy loads.
- Switchgear assemblies: removable or fixed mounting.
- Power plants: protective of auxiliary and distributing circuits.

Construction & operating reliability
The VS1 is fitted with a vacuum component operator that opens and closes with accuracy and longevity.
- Uses vacuum circuit breaker to provide clean arc extinction during interruptions.
- Rated current of 4000A at a breaking capability of 31.5kA.
- Making current capacity of 80kA.
- Mechanical operation of 30,000 cycles.
- Comes with spring mechanism enabling the device to operate manually or electrically.
Technical Parameter
| Parameter | Value |
| Rated voltage | 12 kV |
| Rated frequency | 50 Hz |
| Rated current | 4000 A |
| Rated short-circuit breaking current | 31.5 kA |
| Rated short-circuit making current (peak) | 80 kA |
| Rated short-time withstand current | 31.5 kA / 4s |
| Power-frequency withstand (1 min) | 42/48 kV |
| Lightning impulse withstand | 75/84 kV |
| Mechanical life | 30,000 operations |
| Standard | IEC 62271 / GB 1984 |
Circuit Breaker Price & Factory Quote
The pricing of breakers is determined based on the voltage, current, breaking capacity, mechanism, and number of units ordered. To meet your needs as a manufacturer, we are ready to supply Indoor Vacuum Circuit Breaker at factory prices with discounted prices for volume orders.
- Price list includes available standard models
- For custom options and mechanisms, separate quotation will be provided
- Volume pricing applies for container orders
Breaker Wiring & Control Connection
The power terminals link the breaker to the circuit, and control terminals accept commands to close/open and auxiliary contacts. The Indoor Vacuum Circuit Breaker comes with wiring schemas and labels for the terminal.
- Power terminals tagged as per drawing
- Control circuit wired and confirmed
- Auxiliary contacts provided for indication
Compare Breaker Options
Select the right breaker for your duty:
| Feature | This Breaker | Alternative |
| Voltage | As specified | Other classes available |
| Breaking | Per model | Higher breaking on request |
| Mechanism | Spring / magnetic per model | Manual or motor operation |
| Mounting | Indoor / outdoor per model | Pole or panel mounting |
Export Markets & Country Compatibility
The Indoor Vacuum Circuit Breaker is provided to utility companies and distributors based in Southeast Asia, the Middle East, Africa, Latin America, and South Asia. The ratings, operating mechanism, and certifications are according to the client’s market.
Breaker Dimensions, Weight & Packing
The weight and dimensions of the breakers are determined by the type of voltage and the mechanism of operation in the device. In the case of outdoor pole-operated breakers, the weight and dimensions are small so that the apparatus can be installed easily; for indoor devices, they come completely covered and ready for mounting on the panel. The dimensions and weights for these devices can be confirmed with the order drawings.
- Dimensions by model
- Device closed for transport
- Mounting hardware is optional

Standards & certifications
Compliant with IEC 62271 and GB 1984 standards, the VS1 is provided with type test reports for switchgear and project approval.
- Manufacturing Standards: IEC 62271 / GB 1984.
- Vacuum circuit-breaker process.
- Rated breaking capacity – 31.5KA.
- Mechanical operation tests completed – 30,000.

OEM & B2B supply support
In the role of an experienced producer of power equipment and factory provider, Subian Electric provides switchgear producers, electricity sector and industrial consumers with such services as VCB provision, samples, and technical assistance.
Get in touch with us in case you are in need of any other current ratings or breaking power specifications along with the needed number of items.
- Available samples.
- Flexible quantities for projects and B2B purchases.
- OEM/ODM assistance for integration of switchgear.
- Personalized marking and packaging.
- Documentation and certification assistance.
Frequently Asked Questions
What is the VS1 4000A used for?
The VS1 offers safety to 12kV MV circuits that operate with a potent continuous current of up to 4000A and shows excellent short-circuit performance of 31.5kA.
What is a lateral-type breaker?
The lateral busbar breaker configuration places the isolator and the breaker mechanism together in one unit suitable for powerful indoor switchgears.
What is the mechanical life?
The VS1 provides a mechanical life of 30,000 operations, making it an ideal solution for extensive switching applications.
Can it be integrated into existing switchgear?
Yes, it is adaptable for installation in MV switchgear installations, and comes with options for mount and interlock systems that fit various panels.


























