Product Overview
The ZN12-12/40.5 is an indoor high-voltage AC vacuum circuit breaker for three-phase 50 Hz systems of 12 kV and 40.5 kV, used for protection and control in power plants, substations and industrial networks. The integrated spring energy-storage mechanism and breaker form one compact unit suited to frequent operation and heavy fault interruption, with rated currents up to 3150 A (12 kV) and 2000 A (40.5 kV).
Product Display
Model Designation
The designation identifies the ZN12 design series, the rated voltage class (12 or 40.5 kV) and the rated current together with the rated short-circuit breaking current of the selected variant, as keyed in the figure below. The two platforms are designated ZN12-12 and ZN12-40.5 respectively.
Service Conditions
- Ambient temperature: −10 °C to +40 °C
- Altitude: not exceeding 1000 m above sea level
- Relative humidity: ≤ 95% at 25 °C
- Environment free from hazardous gases, explosive dust and severe vibration
Construction
The operating mechanism and breaker are built as one compact integrated structure with a spring energy-storage mechanism, giving stable operation under frequent switching duty and robust interruption of heavy fault currents. The layout keeps moving masses low and guided, which preserves mechanical alignment over the full service life.
All live parts are housed in an indoor-rated assembly intended for installation in metal-enclosed switchgear. The sealed vacuum interrupters interrupt without oil or gas, eliminating fire and explosion risk and minimising maintenance, while provisions for manual charging and auxiliary signalling keep the unit operable and observable during control-power outages.
Technical Data
| Parameter | ZN12-12 (12 kV) |
ZN12-40.5 (40.5 kV) |
|---|---|---|
| Rated voltage (kV) | 12 | 40.5 |
| Rated frequency (Hz) | 50 | 50 |
| Rated current (A) | 630 1250 1600 2000 2500 3150 |
1250 1600 2000 |
| Rated short-circuit breaking current (kA) | 20 25 31.5 40 |
25 31.5 |
| Rated short-circuit making current (peak, kA) | 50 63 80 100 |
63 80 |
| Rated short-time withstand current (kA/4s) | 20 25 31.5 40 |
25 31.5 |
| Power frequency withstand voltage (kV, 1 min) | 42 (phase-to-phase & phase-to-ground) 48 (isolation gap) |
95 (phase-to-phase & phase-to-ground) 118 (isolation gap) |
| Lightning impulse withstand voltage (kV, peak) | 75 (phase-to-phase & phase-to-ground) 85 (isolation gap) |
185 (phase-to-phase & phase-to-ground) 215 (isolation gap) |
| Mechanical life (operations) | 10000 | 10000 |
| Electrical life (at rated current) | 10000 | 10000 |
Standards
The ZN12 series is designed and tested in accordance with GB 1984 for AC high-voltage circuit breakers (the datasheet references edition GB 1984-89) together with the applicable IEC standards for indoor high-voltage vacuum circuit breakers.
Installation & Dimensions
Installation Diagram
The breaker is supplied for fixed or withdrawable installation in metal-enclosed switchgear. Maintain adequate clearance around the unit for safe operation, maintenance access and heat dissipation during continuous service, and confirm switchgear interfaces (primary contacts, stroke, interlocks, shutters, control plug and earthing) against the approved outline drawing.