The product’s superior insulation and mechanical performance ensure reliable operation even in heavily polluted environments. Equipped with comprehensive mechanical and electrical interlocking devices, it delivers extremely high operational stability and reliability, safeguarding the safety of operators, equipment, and power supply.
● Miniaturization: Minimum cabinet width is 400 mm without earthing switch and 450 mm with earthing switch; cabinet depth is 900 mm.
● Integration: Adopting a frame structure with compact design, it is a high-performance miniaturized high-voltage electrical product integrating disconnector, vacuum circuit breaker and earthing switch.
● Modularization: It adopts the independently developed CTH8 spring operating mechanism with low operating energy. The modular design facilitates inspection and maintenance when necessary.
● When the disconnector is in the open position, the distance between the isolating blade and the cabinet body is more than 125 mm (for 500 mm wide cabinets).
● A metal partition can be installed between the busbar compartment and the switch compartment (compliant with China Southern Power Grid standards).
● The vacuum circuit breaker and load switch share identical external dimensions, facilitating cabinet configuration.
● Comprehensive "Five-prevention" Interlocking Device: The "five-prevention" interlocking for cabinet configuration is simple and reliable.
● (Dual Top and Bottom Isolation): When the disconnector is in the open position, the distance between the isolating blade and the ground remains over 125 mm (for 500 mm wide cabinets).
● Both the disconnector and circuit breaker can be optionally equipped with electric operating mechanisms, which support both electric and manual operation for remote control.
Model Designation

Model	Name
VHX1-12GD	Indoor High-Voltage Alternating-Current Vacuum Circuit Breaker
VHX1-12G2	(Dual Top and Bottom Isolation) Indoor High-Voltage Alternating-Current Vacuum Circuit Breaker

■ Indoor AC High-Voltage Vacuum Circuit Breaker

Note: If the earthing switch is not equipped, the earthing operating shaft shall serve as an interlocking device, and the external dimensions shall remain unchanged.
Operating Environmental Conditions
a. Altitude: not exceeding 1000 m
b. Ambient temperature: -25℃ ~ +40℃
c. Relative humidity: daily average not exceeding 95%, monthly average not exceeding 90%
d. The surrounding air shall be free from obvious pollution by corrosive or flammable gases, water vapor, etc.
e. Locations free from fire and explosion hazards
f. Locations where the seismic intensity does not exceed Grade 8 and the inclination does not exceed 5 degrees
Main Technical Parameters

No.	Name		Unit	VHX1-12D
1	Rated Voltage		kV	12
2	Rated Frequency		Hz	50
3	Rated Current		A	630	1250
4	Rated Short-Circuit Breaking Current		kA	25	31.5
5	Rated Short-Circuit Making Current		kA	63	80
6	Rated Peak Withstand Current		kA	63	80
7	Rated Short-Time Withstand Current	Load Switch (Including Disconnector)	kA/s	25/4	31.5/4
		Earthing Switch	kA/s	25/2	31.5/2
8	Main Circuit Resistance		μΩ	≤90	≤60
9	1-minute Power-frequency Withstand Voltage (RMS Value) - Phase-to-Earth, Phase-to-Phase, Vacuum Fracture/Isolation Fracture		kV/kV	42/48
10	Full-wave Lightning Impulse Withstand Voltage (Peak Value) - Phase-to-Earth, Phase-to-Phase, Vacuum Fracture/Isolation Fracture		kV/kV	75/85
11	Rated Breaking Current for Single Capacitor Bank		A	400
12	Mechanical Service Life		Times	10000
13	Contact Opening Distance		mm	8-10
14	Overtravel (Compression Length of Contact Spring)		mm	3-4
15	Cumulative Wear Thickness of Contacts		mm	3
16	Average Closing Speed		m/s	0.5-0.9
17	Average Opening Speed		m/s	0.9-1.5
18	Rated Contact Pressure		N	2000±200	3100±200
19	Contact Closing Bounce Time		ms	≤2
20	Three-phase Opening and Closing Asynchronism		ms	≤ 1
21	Pole-to-Pole Center Distance		mm	210
22	Distance Between Live Parts and Between Live Parts and Earth		mm	≥125
23	Storage Operating Torque of Vacuum Circuit Breaker		N.m	≤80
24	Closing Operating Force of Vacuum Circuit Breaker		N	≤10
25	Opening Operating Force of Vacuum Circuit Breaker		N	≤10

Structural Features：
All live parts of each phase of the VHX1-12 indoor high-voltage AC vacuum circuit breaker are supported by a single insulating bushing. It integrates the disconnector, vacuum circuit breaker and earthing switch into one unit, featuring a compact structure.
The upper outgoing terminal of the disconnector is connected to the busbar, and the rotating end of the disconnector blade serves as the upper static contact of the vacuum interrupter. The lower outgoing terminal of the vacuum interrupter acts as the static contact of the earthing switch, which effectively saves the valuable space inside the switchgear cabinet.
The busbar compartment and cable compartment of the switchgear cabinet are separated by a metal partition installed in the middle of the insulating bushing. The operating mechanism and the breaker body are integrated into a side-mounted structure, which supports both manual and electric operation modes. The five-prevention interlocking mechanism is integrated inside the operating mechanism box.
Integrated Switch
1、Lightweight, with a weight only three-fifths that of conventional products.
2、Compact size, with a volume only three-fifths that of conventional counterparts; the total height with the earthing blade assembled is 810 mm; suitable for switch cabinets of 400 (450) × 900 × 1600 mm.
3、Low operating power consumption: the motor power is only half that of traditional motors, resulting in less wear and longer service life.
4、Optimized transmission design featuring simplified drive mechanism: the number of transmission components is reduced by one-third compared with conventional switches, ensuring more reliable switching on, switching off and breaking performance.