Factory-Direct Switchgear, Breakers & Regulation Units
Explore our core engineering catalog engineered for industrial substations, utilities, and mission-critical power generation facilities globally.
Architectural Anatomy of Armoured Moving Type (KYN28/KYN61) Switchgear
Armoured moving type switchgear, classified internationally under IEC 62271-200 as metal-clad withdrawable switchgear and standardized within China under the KYN design series (e.g., KYN28A-12 and KYN61-40.5), represents the paramount engineering paradigm for medium-voltage primary distribution networks. Unlike fixed-mounted panels or ring main units (RMUs) designed for secondary distribution, an armoured moving type assembly features a withdrawable circuit breaker truck (handcart) operating inside an earthed, compartmentalized cubicle engineered with structural metallic partitions.
The core structural imperative of this system is total physical segregation. The enclosure is segmented into four distinct, independent, and pressure-relieved compartments:
Circuit Breaker Compartment
Houses the withdrawable truck equipped with vacuum circuit breakers (such as the VS1, VD4, or MRVS1 series). Guided precision rails and automatic safety shutters isolate live busbar contacts the moment the truck moves from the 'Service' to the 'Test/Disconnected' position.
Main Busbar Compartment
Constructed with high-conductivity electrolytic copper busbars (T2 grade), coated with heat-shrinkable cross-linked polyolefin insulation sleeves. Compartmentalized between adjacent panels via pass-through insulating bushings to prevent cascading arc propagation.
Cable & Instrument Compartments
Generously dimensioned cable terminal compartment accommodating multi-core MV cables, current transformers (CTs), zero-sequence sensors, lightning arresters, and high-speed earthing switches. The upper independent LV compartment houses microcomputer-based protection relays and SCADA IEDs.
The Mandatory Five-Anti Interlock Mechanism (五防闭锁): A bedrock requirement of Chinese National Standard GB/T 3906 and global safety practices. It mechanistically prevents: (1) moving the breaker truck while closed, (2) closing the circuit breaker while the earth switch is engaged, (3) closing the earth switch when the breaker is energized, (4) entering a live compartment, and (5) operating the earth switch or breaker truck under unconfirmed safety states.
Engineering Benchmark: Switchgear Topologies Compared
A systematic comparison of Medium Voltage switchgear architectures to guide industrial EPC procurement, consulting engineers, and system designers.
| Performance Vector | Armoured Moving Type (KYN28) | Fixed Metal-Enclosed (XGN) | Gas Insulated Switchgear (GIS) | Secondary RMU (SM6/SafeRing) |
|---|---|---|---|---|
| Primary Rating | 12 kV to 40.5 kV (Up to 4000A) | 12 kV to 24 kV (Up to 3150A) | 12 kV to 72.5 kV (Up to 5000A) | 12 kV to 24 kV (Up to 630A) |
| Withstand Capacity (Icw) | 31.5 kA to 50 kA (4s duration) | 25 kA to 31.5 kA (4s duration) | 31.5 kA to 50 kA (3s duration) | 16 kA to 20 kA (1s to 3s) |
| Service Continuity (LSC) | LSC2B (Maximum operational uptime) | LSC2A / LSC1 (Partial isolation) | LSC2B (Gas compartment shielded) | LSC2A (Compact loop continuity) |
| Breaker Maintainability | Immediate withdrawable racking (<3 min) | De-energization & unbolting (>4 hrs) | Specialized SF6 evacuation required | Integral three-position load switch |
| Enclosure Partition Class | PM (Metallic, continuously earthed) | PI / PM (Mixed metallic/insulating) | Hermetic Stainless Tank | Partially metallic insulated |
| Capex vs. Opex Balance | Optimal lifecycle Capex & local spares | Lowest initial Capex, elevated downtime | High Capex; low footprint, complex end-of-life | Low-to-medium cost for compact rings |
Why Tier-1 EPCs Source MV Switchgear from China
The convergence of localized component clustering, advanced automated metal-forming lines, and rigorous ISO/CNAS type-testing laboratories creates unmatched procurement value.
Integrated Yueqing Component Matrix
Yueqing (Wenzhou) serves as the world's dense electrical epicenter. Within a 25-kilometer radius, factories source Aluzinc steel sheets, vacuum interrupters, tulip contact fingers, epoxy insulators, and microprocessor relays, shortening lead times from 16 weeks to 3-5 weeks.
Automated CNC Precision Fabrication
Our automated production floors utilize imported Trumpf CNC multi-station punch presses and robotic laser cutting tables. Panels are constructed from high-yield 2.0mm aluminum-zinc coated steel plates, cold-bent in a single process without welds to maximize anti-corrosion and ground integrity.
CNAS & STL Certified Type Testing
Every switchgear architecture manufactured complies with rigorous third-party verification protocols. Full type test portfolios from testing organizations such as XIHARI, KEMA, and ASTA confirm short-circuit withstand, temperature rise limits, mechanical endurance, and IAC AFLR arc-containment compliance.
Engineered Deployments Across Strategic Sectors
Armoured moving type switchgear delivers uninterrupted power control across the most demanding industrial topologies worldwide.
Hyperscale Data Centers & Financial Hubs
Demanding Tier-IV electrical availability, our switchgear integrates automatic transfer switching (ATS) systems and motorized withdrawable racking, ensuring rapid fault clearance without disrupting adjacent live server halls.
Utility Substations & Regional Grids
Serving national distribution operators throughout Southeast Asia, the Middle East, and Latin America. Built for heavy duty thermal cycles, withstand up to 4000A rated busbar currents, and remote IEC 61850 substation automation.
Heavy Metallurgy & Petrochemicals
Harsh atmospheres demand elevated ingress protection (IP4X externally, IP2X between compartments). Specially treated anti-sulfur contacts, sealed bus compartments, and gas-deflecting blast ducts protect personnel against severe fault events.
Emerging Paradigms in Medium-Voltage Technology
The industry is transitioning toward condition-based intelligence, worker safety mechanics, and environmentally neutral media.
1. Online Condition Monitoring & Thermal Sensor Arrays
Conventional periodic maintenance schedules are giving way to real-time predictive analytics. Modern KYN28 assemblies feature surface-acoustic-wave (SAW) passive wireless temperature sensors directly clamped onto moving tulip contacts and busbar transition joints. Because loose mechanical joints and oxidation trigger thermal runaway, real-time wireless temperature telemetry prevents catastrophic flashovers before they happen.
2. Remote Motorized Truck Racking for Zero Arc-Flash Exposure
Operator safety during the racking of circuit breakers between the 'Disconnected' and 'Service' positions is paramount. Our modernized enclosures provide internal motorized worm-gear drives operable via front-door pushbuttons or external tablets from outside the arc-flash boundary zone (exceeding 10 meters distance), completely safeguarding maintenance personnel against arc blast hazards.
3. SF6-Free Environmental Compliance
While gas-insulated systems traditionally relied heavily on sulfur hexafluoride (a potent greenhouse gas with a GWP of 23,500), armoured air-insulated switchgear (AIS) stands as the inherently sustainable, circular-economy choice. Utilizing dry air, high-purity nitrogen, or pure vacuum interruption (as in our VS1/ZN63A series), operators circumvent F-gas regulatory quotas, mandatory gas tracking records, and high decommissioning tariffs.
Enterprise Specification Guide for Tender Documents
Ensure flawless RFQ execution by standardizing these critical technical parameters when engaging Chinese manufacturers.
Single-Line Diagram (SLD) Definition
Detail exact feeder functions: incoming, bus coupler, bus metering, feeder protection, or transformer step-down. Define CT ratios, accuracy classes (e.g., 0.2S for metering, 5P20 for protection), and PT connection types.
Dielectric & Dynamic Withstand
Specify rated power frequency withstand voltage (Ud up to 95 kV for 40.5 kV) and lightning impulse withstand voltage (Up/BIL up to 185 kV peak). Confirm rated peak withstand (Ip up to 130 kA) and short-time withstand (Icw up to 50 kA / 4s).
Ambient & Environmental Derating
Indicate site altitude (standard ratings are valid up to 1000m; higher elevations require dielectric clearance derating), ambient temperature ranges (-25°C to +45°C), relative humidity profiles, and seismic zone qualifications.
Integrated Switchgear Components & Power Transformers
Complete your balance of plant with certified vacuum circuit breakers, intelligent air breakers, dry-type transformers, and precision isolating switches.
Frequently Asked Questions on MV Armoured Switchgear
Direct technical answers from senior application engineers covering standards compliance, maintenance, installation, and procurement.