Product Overview
The KYN28-12 is a three-phase, AC 50Hz/60Hz, indoor, armored, withdrawable metal-enclosed switchgear designed for rated voltages up to 12kV. This switchgear is widely used in power receiving, distribution, and control applications in power plants, substations, industrial enterprises, commercial buildings, and urban power distribution networks. It provides reliable protection, control, and isolation for power transmission and transformation systems.
The switchgear complies with GB 3906, IEC 62271-200, and DL/T 404 standards, featuring a modular design with multiple functional compartments including the circuit breaker compartment, busbar compartment, cable compartment, and auxiliary compartment. The withdrawable circuit breaker design enables convenient maintenance, inspection, and replacement without interrupting system operation.

Key Features
1. Armored & Metal-Enclosed Construction
The switchgear is constructed with high-strength, corrosion-resistant steel plates, forming a robust, fully enclosed structure that ensures personnel safety and equipment protection. The armored design provides effective internal arc containment and external impact resistance, complying with IAC internal arc fault classification requirements.
2. Withdrawable Circuit Breaker Design
The circuit breaker is mounted on a withdrawable trolley mechanism, allowing easy removal and reinsertion for maintenance, inspection, and replacement purposes. This design minimizes system downtime and simplifies servicing operations. The withdrawable unit supports smooth rolling and precise positioning with stable and reliable mechanical interlocking mechanisms.
3. Modular Functional Compartment Layout
The switchgear is divided into four independent functional compartments including the circuit breaker compartment for housing the withdrawable vacuum circuit breaker, the busbar compartment for main and branch busbars, the cable compartment for cable termination and connection, and the auxiliary compartment for control, protection, metering, and monitoring equipment. Each compartment is separated by metal partitions with pressure relief channels for enhanced safety.
4. Comprehensive Mechanical & Electrical Interlocking
The switchgear incorporates reliable interlocking mechanisms including five-prevention interlocking functions and safety interlocks between the circuit breaker, earthing switch, cable compartment door, and operating mechanisms. These interlocks effectively prevent operational errors and ensure compliance with safety regulations.
5. Advanced Vacuum Circuit Breaker Technology
Equipped with high-performance vacuum circuit breakers featuring long electrical life and excellent breaking capacity. The vacuum interrupter ensures reliable arc interruption with minimal maintenance requirements and environmental friendliness. The circuit breaker is available with spring-operated or permanent-magnet operating mechanisms.
6. Flexible Busbar & Cable Options
The main and branch busbars are made of high-conductivity copper with silver-plated connections for low contact resistance. Busbar systems are available in single-busbar and double-busbar configurations. The cable compartment provides ample space for cable termination, supporting top, bottom, or side cable entry and exit.
7. Intelligent Monitoring & Protection
The switchgear supports optional smart monitoring systems with integrated protection relays, digital measurement, and communication capabilities. Standard communication protocols including IEC 61850, Modbus, and DNP3 enable seamless integration with SCADA and substation automation systems for remote monitoring and control.
8. Internal Arc Fault Protection
The enclosure design incorporates pressure relief channels and arc-resistant features compliant with IAC classifications. In the event of an internal fault, the pressure relief system directs arc gases to designated exhaust areas, protecting nearby personnel and equipment. The arc fault protection is available in AFL, AFLR, and ALE configurations.

Technical Specifications
Rated Voltage: 12kV
Rated Insulation Level: 42kV (power frequency withstand voltage) / 75kV or 95kV (lightning impulse withstand voltage)
Rated Frequency: 50Hz or 60Hz
Main Busbar Rated Current: 630A, 1250A, 1600A, 2000A, 2500A, 3150A, 4000A (customizable)
Branch Busbar Rated Current: 630A, 1250A, 1600A, 2000A, 2500A, 3150A (customizable)
Rated Short-Time Withstand Current: 20kA, 25kA, 31.5kA, 40kA, 50kA (depending on configuration)
Rated Peak Withstand Current: 50kA, 63kA, 80kA, 100kA, 125kA (depending on configuration)
Internal Arc Classification: IAC - AFLR up to 40kA/1s or 50kA/1s
Protection Rating: IP4X (front panel), IP2X (other panels and external parts)
Dimensions (Width × Depth × Height): 800mm or 1000mm × 1500mm × 2300mm (typical, customizable)
Circuit Breaker Type: Vacuum circuit breaker with withdrawable mechanism
Operating Mechanism: Spring-operated mechanism or permanent-magnet mechanism
Busbar System: Single-busbar or double-busbar configurations
Operation Mode: Local manual operation, remote electrical operation (optional)
Cable Termination: Top, bottom, or side cable entry and exit (field adaptable)

Applications
The KYN28-12 switchgear is extensively used in secondary substations for urban and regional power distribution networks. It is also employed in industrial power systems for mining, metallurgy, petrochemical, and manufacturing facilities. Commercial and high-rise building power distribution systems benefit from its reliable protection and compact footprint. Infrastructure projects including airports, railway stations, ports, and tunnels utilize KYN28-12 for reliable medium-voltage power distribution. Renewable energy applications such as photovoltaic plants, wind farms, and energy storage systems also employ this switchgear for power collection and interconnection. Utility companies rely on KYN28-12 for distribution substation applications and grid automation projects.

Compliance Standards
GB 3906-2020 Alternating Current Metal-Enclosed Switchgear and Controlgear for Rated Voltages Above 3.6kV and Up to and Including 40.5kV, IEC 62271-200 High-Voltage Switchgear and Controlgear – Part 200: AC Metal-Enclosed Switchgear and Controlgear for Rated Voltages Above 1kV and Up to and Including 52kV, DL/T 404 Technical Specification for Indoor AC High-Voltage Switchgear, and JB/T 8754 Technical Specification for High-Voltage Switchgear.

Why Choose Us
Our manufacturing facilities employ advanced production equipment including CNC punching, bending, and shearing machines for precision fabrication. We perform comprehensive quality control including primary and secondary wiring verification, mechanical operation tests, power frequency withstand voltage tests, and protection relay calibration before delivery. Customization options are available for busbar configuration, circuit breaker ratings, and control logic to meet specific project requirements. Our engineering team provides professional technical support for system design, installation, and commissioning. We offer prompt delivery and competitive pricing through efficient manufacturing processes. Comprehensive after-sales service includes installation guidance, commissioning assistance, spare parts supply, and remote technical support. Our switchgear has been installed in numerous substations worldwide with proven reliability and customer satisfaction.