VTZ-12 1250A vacuum circuit breaker (special model of Tongzhong Electrical Co., Ltd.) is an indoor switchgear for rated voltage 12kV,1250A, AC 50/60Hz. It adopts a modular operating mechanism and is suitable for various industrial and mining enterprises, as well as power grid equipment. It can be used as a handcart unit for use with KYN28A-12 switchgear, or as a fixed unit with relevant mechanical interlocking, making it suitable for XGN2 and other fixed cabinets.

Product Specifications

Specification Sheet

No.	Name	Unit	Data
1	Rated Voltage	kV	12
2	Rated Frequency	Hz	50/60
3	Rated Current	A	1250
4	Rated PowerFrequency Withstand Voltage	kV	48(Across the Contact Gaps) / 42(To Ground)
5	Rated Lightning Impulse Withstand Voltage	kV	75
6	Rated Short-Circuit Breaking Current	kA	25/31.5/40/50
7	Rated Short-Circuit Making Current (Peak)	kA	63/80/100/125
8	Rated Withstand Current (Peak)	kA	63/80/100/125
9	Rated Duration of Short-Circuit	s	4
10	Operating Cycles at Rated Short-Circuit Breaking Current	Cycles	E2
11	Mechanical Endurance	Times	30000
12	Standard Operating Sequence	-	O-0.3s-CO-180s-CO
13	Allowable Wear Thickness of Contact	mm	≤3

Mechanical Characteristics

No.	Name	Unit	Data
1	Clearance between Moved and Fixed Contact	mm	9±1
2	Contact Overtravel	mm	3.5±0.5
3	Average Closing Speed	m/s	0.7±0.2
4	Average Opening Speed (Average Speed of First Opening at 6mm)	m/s	1.1±0.2
5	Rated Contact Pressure	N	2500±200N(25kA) 3100±200N(31.5kA) 4800±300N(40kA) 6000±500N(50kA)
6	Closing Time	ms	30～70
7	Opening Time	ms	20～50
8	Contact Bouncing Duration at Closing Operation	ms	≤2
9	No-Simultaneity of Closing/Opening Operations of 3-Phase	ms	≤2

Product Advantages

VTZ-12 1250A vacuum circuit breaker has many advantages:

Performance of circuit breaker：

E2-C2-M2

Convenient maintenance:

the modular mechanism design allows for easy replacement of the closing and opening coils without the need for dismantling other components. This eliminates the need for testing or adjustment after replacement, ensuring users to replace them independently, making subsequent maintenance more convenient.

High conductivity performance:

the product features a well-designed conductive circuit that meets 1.1 times the rated current temperature rise level.

Wide application range:

the product series has a wide application range, rated currents from 630A to 5000A, and rated breaking currents from 20kA to 50kA. It is suitable for all environments within an altitude of 4500 meters and an operating temperatures from -40°C to 40°C.

Supports intelligent customization:

a. It can add a wireless temperature monitoring solution with self-powered design to ensure safety and maintenance-free operation.

b. It has a mechanical characteristics monitoring solution to provide real-time monitoring of circuit breaker operating data for early detection and resolution of potential problems.

c. It has a motorized cabinet entry solution to allow remote operation for ensuring personal safety.

d. Real-time component aging can be detected by partial discharge testing.