Indoor Vacuum Circuit Breaker

12 kV indoor vacuum circuit breakers for switching and protection in medium-voltage power systems.

Wafr supplies indoor vacuum circuit breakers for use in three-phase medium-voltage switchgear. Units are available in side-mounted, front-mounted and withdrawable configurations, with manual or motorized operation and multiple protection and control options.

Key Specifications

Specification	Configuration
Rated Voltage	12 kV
Rated Lightning Impulse Withstand Voltage (peak)	75 / 85 kV
Rated Power Frequency Withstand Voltage (1 min)	42 / 48 kV
Rated Frequency	50 / 60 Hz
Rated Short-Circuit Breaking Current	20 / 25 / 31.5 / 40 kA
Rated Current	630–1250 A (20/25 kA class); 1250–2500 A (31.5 kA class); 1250–4000 A (40 kA class)
Rated Short-Time Withstand Current	20 / 25 / 31.5 / 40 kA
Rated Peak Withstand Current	50 / 63 / 80 / 100 kA
Rated Short-Circuit Making Current (peak)	50 / 63 / 80 / 100 kA
Secondary Circuit Power Frequency Withstand Voltage (1 min)	2,000 V
Rated Operating Sequence	O-0.3s-CO-180s-CO
Rated Short-Circuit Duration	4 s
Rated Single/Back-to-Back Capacitor Bank Breaking Current	630/400 A; 800/400 A
Rated Capacitor Bank Making Inrush Current	12.5 kA (frequency less than 1,000 Hz)
Mechanical Endurance	10,000 cycles
Rated Number of Short-Circuit Current Interruptions	30 cycles (≤31.5 kA); 20 cycles (40 kA)
Accumulated Thickness of Wear Allowed for Dynamic/Static Contacts	3 mm
Rated Closing and Opening Operating Voltage	AC 220/110 V; DC 220/110 V
Contact Opening Distance, Overtravel	Opening distance 10±1 mm; overtravel 3±1 mm
Closing and Opening Time (at rated operating voltage)	Closing ≤70 ms; opening ≤50 ms
Contact Closing Bounce Time	2 ms (≤31.5 kA); 3 ms (40 kA)
Three-Phase Closing and Opening Synchronization	2 ms
Average Opening Speed	0.9–1.3 m/s
Average Closing Speed	0.4–0.8 m/s
Main Circuit Resistance	630 A: ≤50 μΩ; 1250 A: ≤45 μΩ; 1600/2000 A: ≤40 μΩ; above 2500 A: ≤30 μΩ

Available Configurations

Mounting

Side-mounted, front-mounted or withdrawable

Pole Construction

Insulated cylinder or solid-insulation embedded pole

Operation

Manual or motorized

Operating Supply

AC or DC, 110 / 220 V

Protection Options

Overcurrent trip coils, voltage-loss trip coil, locking and anti-tripping functions

Product Features

Vacuum arc extinguishing: The novel longitudinal magnetic field vacuum interrupter has better arc extinguishing performance and lower operating overvoltage.
Superior performance: The conductive part of the pole and the ceramic vacuum arc extinguishing chamber are both enclosed in an epoxy resin sleeve, preventing damage to the vacuum arc extinguishing chamber and ensuring high resistance in humid, hot, and polluted environments. Important functional components such as energy storage, retention, and release are all treated with strengthening and surface treatment, making the mechanism components more corrosion-resistant, wear-resistant, and reliable.
Flexible structure: Modular spring switching mechanism, more reliable opening and closing operation, and more convenient maintenance.
Easy operation: Operation mode is manual or motorized. Motorized operating power supply is AC/DC universal, 220 or 110V. The maximum number of optional devices is two overcurrent trip coils plus one voltage loss trip coil, or three overcurrent trip coils plus one locking.
Stable and reliable: The optimization design of optional devices such as anti-tripping and locking, overcurrent tripping, and voltage loss tripping, as well as the secondary circuit, provides strong guarantees for the reliable and safe operation of circuit breakers, and also provides users with more choices and interfaces in the design of protection and intelligent control.
Good suitability: Excellent performance, stable operation, long service life, minimal maintenance, no explosion hazard, no pollution, low operating noise.

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Indoor Vacuum Circuit Breaker

Key Specifications

Available Configurations

Key Features

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