Name: China VTZ-12MT 12kV Mining VCB for Underground Coal Mine Manufacturers Suppliers Factory
Brand: XDTZ
SKU: 255215177

VTZ-12MT mine explosion-proof vacuum circuit breaker

In the harsh, dusty, and potentially explosive environments of underground coal and metal mine operations, reliable electrical protection is non-negotiable. The VTZ-12MT (Tongzhong Electric Special Type) is a key component-an explosion-proof switchgear-designed specifically for modern mine power distribution systems.

This circuit breaker is handle underground mine operations with a rated voltage of 12kV and an AC frequency of 50/60Hz. It uses a permanent magnet mechanism and features mechanical manual closing and opening functions, making it suitable for environments requiring explosion-proof protection for electrical equipment. Its withdrawable design is compatible with the PJG9-10 type switchgear.

VTZ-12MT mine explosion-proof vacuum circuit breaker

Mine Explosion-proof VCB IN STOCK

VTZ-12MT mine explosion-proof vacuum circuit breaker

Mine Explosion-proof VCB Before Packing

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 Power Frequency 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
7	Rated Short-Circuit Making Current (Peak)	kA	63
8	Rated Withstand Current (Peak)	kA	63
9	Rated Duration of Short-Circuit	s	4
10	Operating Cycles at Rated Short-Circuit Breaking Current	Times	E2
11	Mechanical Endurance	Times	20000
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±0.5
3	Average Closing Speed	m/s	0.6±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)
6	Closing Time	ms	≤100ms
7	Opening Time	ms	≤100ms
8	Contact Bouncing Duration at Closing Operation	ms	≤2
9	No-Simultaneity of Closing/Opening Operations of 3-Phase	ms	≤2

Product Advantages

VTZ-12MT mine explosion-proof vacuum circuit breaker has many advantages:

Performance of circuit breaker

E2-C2-M2

Safety and reliability

the circuit breaker utilizes a combination of permanent magnet operation mechanism and spring operation mechanism. In normal operation, the permanent magnet mechanism is used. In the event of a fault in the permanent magnet mechanism, the breaker can still be manually closed and opened, ensuring safe and reliable operation. The breaker, when paired with the switchgear, achieves a reliable mechanical interlock, ensuring the safety of operating personnel.

High conductivity performance

it features a rationally designed conductive circuit, ensuring that it meets the temperature rise requirements of 1.1 times the rated current.

Intelligent configuration

a. A self-powered wireless temperature monitoring system can be added, providing a safe, maintenance-free solution.

b. Mechanical characteristics monitoring program can continuously monitors the breaker's operational data, enabling early detection and resolution of potential issues.

c. A motorized cabinet insertion design allows for remote operation, ensuring personnel safety.

d. Partial discharge detection allows real-time detection of component aging.

Product Applications

VTZ-12MT mine explosion-proof vacuum circuit breaker has many applications:

Coal mining industry

Metal mining industry

Product Outline Drawing

VTZ-12MT Mine Explosion-Proof Vacuum Circuit Breaker outline drawing

Secondary Wiring Diagram

VTZ-12MT Mine Explosion-Proof Vacuum Circuit Breaker Secondary Wiring Diagram

Mechanism Operating of VTZ-12MT Mine Explosion-Proof VCB

VTZ-12MT Mine Explosion-Proof Vacuum Circuit Breaker operating mechanism

The VTZ-12MT Mine Explosion-Proof Vacuum Circuit Breaker uses a permanent magnet for terminal position holding and generates brief closing and opening forces via an electronically controlled coil. Its simple structure mainly consists of moving and stationary iron cores, a permanent magnet, and an electronic control module.

Working Principle of the Permanent Magnet Mechanism: Simple and Direct
Traditional spring mechanisms rely on spring energy storage and a series of connecting rods and half-shafts to "lock" or "release" the position. The core logic of the permanent magnet mechanism is "electric drive, permanent magnet holding":

Position Holding: When the vcb is in the closed or open position, the high-performance permanent magnet's magnetic force firmly holds the moving iron core to the end cover, requiring no mechanical fasteners or continuous energization.

Action Process: When opening or closing is required, a brief pulse current is applied to the coil, generating a magnetic field opposite to the direction of the permanent magnet force, canceling the permanent magnet force. Under the action of spring force or electromagnetic force, the moving iron core quickly moves to the other end, completing the operation.