VTZ-12 630A vacuum circuit breaker, a special model developed by Tongzhong Electrical Co., Ltd., is an indoor vacuum circuit breaker designed for a rated voltage of 12kV, rated current of 630A, and AC frequency of 50/60Hz. It adopts a modular operating mechanism with a compact and practical structural design, providing reliable closing and opening performance as well as convenient operation and maintenance.

The circuit breaker is suitable for various industrial and mining enterprises, power distribution systems, and power grid equipment, meeting the requirements of medium-voltage switching, control, and protection applications. It can be configured as a withdrawable handcart unit for use with KYN28A-12 switchgear, allowing convenient installation, withdrawal, inspection, and maintenance. It can also be configured as a fixed unit with the corresponding mechanical interlocking components, making it suitable for XGN2 and other fixed-type switchgear cabinets.

With its reliable operating mechanism, flexible installation options, and stable electrical performance, the VTZ-12 630A provides a practical and dependable solution for medium-voltage power distribution and electrical equipment applications.

VTZ-12 Vacuum Circuit Breaker

Product Specifications

Specification Sheet

No.	Name	Unit	Data
1	Rated Voltage	kV	12
2	Rated Frequency	Hz	50/60
3	Rated Current	A	630
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 630A 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 the temperature rise requirements at 1.1 times the rated current, ensuring reliable current-carrying capacity and stable electrical performance. This design helps minimize heat generation during continuous operation and improves the overall safety, reliability, and service life of the circuit breaker.

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 be equipped with a wireless temperature monitoring solution featuring a self-powered design to ensure safe, reliable, and maintenance-free operation. It continuously monitors the temperature of key components, helping detect abnormal temperature rises at an early stage and reduce potential equipment failures.

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. It helps identify abnormal operating conditions in time, enabling preventive maintenance and improving the reliability and service life of the circuit breaker.

c.It has a motorized cabinet entry and withdrawal solution to allow remote operation, reducing the need for personnel to approach high-voltage equipment directly and ensuring personal safety. It also improves operating convenience and efficiency, making the equipment more suitable for safe and reliable remote operation.

d. Real-time component aging can be detected through partial discharge testing, helping identify insulation deterioration and potential defects at an early stage. This enables timely maintenance and reduces the risk of unexpected equipment failures.