19.August
Vacuum Circuit Breaker Type OVB-VBF 35 kV: Reliability and Technology in Switching
The OVB-VBF 35 kV vacuum circuit breaker is designed to control 35 kV electrical circuits in three-phase AC networks with insulated or partially earthed neutrals. It ensures stable operation of the network in both normal and emergency modes at a frequency of 50 Hz.
Construction and Components
This breaker is a live tank type, where the switching mechanism is housed inside insulating porcelain enclosures filled with gas (sf6) or nitrogen under pressure. This solution minimizes the risk of moisture formation and ensures the device’s longevity.
Main Parts of the Circuit Breaker:
- Pole Assembly: Includes the vacuum chamber, contacts, insulating linkage housed in a porcelain enclosure, and the overall drive mechanism.
- Actuator Cabinet: Contains a weatherproof spring mechanism and additional equipment such as heating, position indicators, a mechanical counter, circuit breakers, relays, interlocks, etc.
- Steel Frame: Sturdy corner supports that can be adapted to accommodate additional elements such as current transformers.
Advantages and Features
The OVB-VBF 35 kV circuit breaker features advanced solutions from ABB:
- Vacuum switching ensures high reliability and durability.
- It complies with international IEC and Class C2 standards, minimizing the risk of restriking when operating with capacitive loads.
- Porcelain enclosures are suitable for outdoor use and provide protection against fire and external influences.
- The simple and efficient spring mechanism requires minimal maintenance.
- Capability to perform an O-B-O cycle without intermediate recharging.
- Fast spring compression by the motor (up to 15 seconds).
- Additional contacts (13 NO + 13 NC) and an optional additional trip coil.
Operation and Maintenance
The circuit breaker is delivered pre-assembled, significantly reducing installation time. Its modular design simplifies maintenance, and the use of modern materials ensures a long service life. If necessary, it can be transported in separate parts.
Testing and Certification
Each circuit breaker undergoes comprehensive testing according to IEC 62271-100, including structural integrity, voltage tests, switching speed, and surge protection, to ensure it meets the highest standards of quality and reliability.
| Live-Tank circuit breaker | OVB-VBF 36 | |||
| Standard | IEC 62271-100 | |||
| Rated voltage | kV | 36 | ||
| Insulation voltage | кВ | 36 | ||
| Испытательное напряжение | kV/min | 70(dry)/70(wet) | ||
| Impulse voltage | kVp | 170 | ||
| Nominal frequency | Hz | 50-60 | ||
| Rated current | A | 1250 | 2000 | 2500 |
| Symmetrical breaking current | kA | 25 | 25 | 31,5 |
| Short-circuit current (3s) | kA | 25 | 25 | 31,5 |
| Asymmetrical breaking current | (% of constant component at t=45ms)kA | 35 | ||
| Switching current | kAp | 63 | 63 | 80 |
| Own switch-off time | ms | 45 | ||
| Switching capacity at capacitive currents | A | 400 | ||
| Arc burning time | ms | 5-15 | ||
| Total switch-off time | ms | 50-60 | ||
| Switch-on time | ms | 75 | ||
| Dimensions | With supports (HхLхD) mm | (3090-3840)х900х686 | ||
| Weight | kg | 850/900 | ||
| Absolute pressure N2 | kPa anti-condensation | 150 | ||
| Operating temperature | °С | -25(-40) … +40 | ||
The OVB-VBF 35 kV vacuum circuit breaker is a modern solution for efficient switching in demanding environments. With its innovative technology, high reliability, and ease of maintenance, it is the optimal choice for distribution networks and industrial facilities.