Description
VBI 12kV Indoor Vacuum Circuit Breaker Overview
The VBI is a three-phase AC 50 Hz indoor vacuum circuit breaker rated at 12 kV. The published table lists 630 A, 1,250 A, 2,000 A, and 3,150 A current options with 20 kA, 25 kA, 31.5 kA, and 40 kA short-circuit breaking-current options.
The existing page identifies control and protection duties in power plants, substations, and industrial power systems, including installations that require frequent operation.
Operating Conditions
- Ambient temperature: -10°C to 40°C; storage down to -30°C
- Maximum altitude: 1,000 m
- Maximum daily average relative humidity: 95%
- Maximum monthly average relative humidity: 90%
- Maximum daily average saturated vapor pressure: 2.2 × 10-3 MPa
- Published monthly saturated-vapor-pressure value: 1.8 × 10-2 MPa
- Condensation may occur when temperature drops sharply
- Maximum earthquake intensity: 8
- No fire, explosion, severe pollution, chemical corrosion, or severe vibration
Electrical Ratings
| Parameter | Published value |
|---|---|
| Rated voltage | 12 kV |
| 1-minute power-frequency withstand voltage | 42 kV |
| Lightning impulse withstand voltage | 75 kV |
| Rated current | 630 A / 1,250 A / 2,000 A / 3,150 A |
| Rated short-circuit breaking current | 20 kA / 25 kA / 31.5 kA / 40 kA |
| Rated short-circuit making current, peak | 50 kA / 63 kA / 80 kA / 100 kA |
| Rated peak withstand current | 50 kA / 63 kA / 80 kA / 100 kA |
| Rated thermal-stability current, RMS | 20 kA / 25 kA / 31.5 kA / 40 kA |
| Thermal-stability time | 4 seconds |
| Rated operating sequence | O–0.3 s–CO–180 s–CO |
| Mechanical life | 10,000 operations |
| Single capacitor-bank breaking current | 630 A |
| Back-to-back capacitor-bank breaking current | 400 A |
Application and Selection
Select the rated current and short-circuit rating as a matched configuration. Also confirm the operating sequence, capacitor-bank duty where applicable, installation type, control supply, altitude, humidity, seismic condition, and surrounding environment.
Information for an Inquiry
Provide the rated current, prospective short-circuit current, operating sequence, load and capacitor-bank duty, switchgear arrangement, control voltage, altitude, humidity, and seismic requirements.
FAQ
Which current ratings are listed for the VBI 12kV breaker?
Which short-circuit breaking ratings are listed?
What operating sequence is specified?
What capacitor-bank values are listed?
What should be provided for selection?
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