What Is Metal-Clad Switchgear?
Metal-clad (or metal enclosed) switchgear packages all primary live parts—busbars, circuit breakers, disconnect switches, and instrument transformers—within grounded, welded-steel compartments. The KYN61-40.5 kV series specifically features:
- Withdrawable Vacuum Circuit Breakers (VCBs): Modules can be racked in/out for maintenance without live-part exposure.
- Air-Insulated Compartments: SF₆-free design uses clearances in air to achieve 40.5 kV insulation levels, avoiding gas safety concerns.
- Modular Construction: Standardized units for circuit breakers, bus connections, current transformers, and protection relays.
By housing everything in grounded metal enclosures, this switchgear ensures personnel safety, simplifies maintenance, and supports high-reliability operation in demanding environments.
Key Features, Advantages & Application Fields
2.1 Withdrawable Module Design
- Easy Maintenance: Circuit breaker units (VD4-36E vacuum interrupters) slide on insulated rails. Technicians can test or replace them offline.
- Interlocked Access: Mechanical and electrical interlocks prevent racking under load or when grounded, reducing human error.
- Flexible Configuration: Modules for circuit breakers, isolating switches, earthing switches, PT trucks, and fuse units can be combined to match network topology.
2.2 Intelligent Operational System
- Remote & Local Control: Breaker open/close and grounding switch operations can be executed locally via hand-wheels or remotely via SCADA.
- Visual Indicators & Temperature Monitoring: All primary contacts feature clear position indicators; temperature sensors on busbars grant early warning of hot spots.
- Fault Diagnosis: Online detection of contact resistance, breaker operating time, insulation levels, and partial discharge helps predict maintenance needs.
2.3 Robust Metal Enclosure
- Safety & Durability: IP4X protection to the front; IP2X between compartments prevents accidental contact with live parts.
- Grounded Steel Panels: Welded, bolted enclosures serve as Faraday cages, shielding operators and sensitive electronics.
- Corrosion Resistance: Powder-coated or galvanized finish withstands industrial atmospheres and UV exposure.
2.4 Wide-ranging Applications
- Utility Substations: Feeder, ring-main, and transformer protection in 36 kV overhead and cable networks.
- Industrial Plants: Mining, petrochemical, and steel mills where robust fault-clearing capability is critical.
- Renewable Energy: Wind farm and solar park collection and grid-interface points requiring reliable high-voltage interruption.
- Commercial Complexes: Large data centers, hospitals, and campuses with stringent uptime requirements.
Technical Specifications & Comparison
| Parameter | Data |
|---|---|
| Rated Voltage | 40.5 kV / 36 kV / 35 kV / 33 kV |
| Rated Frequency | 50/60 Hz |
| Busbar Current Rating | 630 A, 1250 A, 1600 A, 2000 A, 2500 A |
| Branch Circuit Current | 630 A, 1250 A, 1600 A, 2000 A |
| Short-Time Withstand Current (4 s) | 16, 20, 25, 31.5 kA (rms) |
| Peak Withstand Current | 40, 50, 63, 80 kA |
| Power-Frequency Withstand Voltage (1 min) | 95 kV (phase-to-earth) / 118 kV (across open contacts) |
| Lightning Impulse Withstand | 185 kV (phase-to-earth) / 215 kV (open contact) |
| Protection Degree | Enclosure: IP4X; Between compartments: IP2X |
| Standards Compliance | IEC 62271-200; GB /T 11022; IEEE C37.20 |
Comparison with KYN28A
KYN61-40.5 kV offers higher insulation level (40.5 kV vs. 12 kV) and uses vacuum interrupters instead of air or oil.
Modular, detachable design simplifies maintenance compared to fixed, bolted-in switchgear.
How KYN61-40.5 kV Stands Out
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Vacuum Interruption Technology
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Eco-Friendly Operation: No SF₆ gas—vacuum interrupters eliminate greenhouse concerns.
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High Breaking Capacity: Up to 31.5 kA (rms) fault clearing with minimal contact erosion.
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Advanced Protection & Monitoring
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Thermal Imaging Integration: Optional infrared scan ports allow periodic busbar temperature checks without opening panels.
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Digital Relay Suite: Microprocessor relays support distance, overcurrent, under-frequency, and arc-flash detection in one chassis.
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Event & Waveform Recording: Capture transient disturbances for expert analysis and faster troubleshooting.
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Safety-First Interlocks
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Racking Interlocks: Prevent circuit breaker withdrawal when in service.
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Grounding Switch Interlocks: Guarantee the earthing switch only engages when the breaker is isolated.
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Door-Lock Interlocks: Doors cannot open unless the module is safely isolated.
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Customizable Layout
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Cell-by-Cell Design: Build up to six modules per bay—feeders, transformers, capacitor banks, or motor control centers.
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Space-Saving Footprint: Narrow aisles and compact height suit retrofit into existing buildings or mobile substations.
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5. Buying Advice & Selection Guidance
When specifying your next High Voltage Board, keep these considerations in mind:
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System Voltage & Fault Levels
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Confirm the system’s maximum short-circuit current and ensure the switchgear’s 4 s withstand and peak withstand ratings exceed it by 10–20%.
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Current Ratings & Growth Plans
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Choose busbar and branch currents to cover present loads plus future expansions.
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Maintenance Philosophy
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If minimal downtime is critical, prioritize withdrawable modules and online monitoring features.
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Environmental Conditions
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For high-corrosion or outdoor unconditioned spaces, select galvanized or stainless-steel enclosures with appropriate IP ratings.
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Integration & Control
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Align protection relays and SCADA protocols (IEC 61850, DNP3, Modbus) with your existing network management systems.
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Certification & Support
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Choose products with ISO 9001, CE, and IEEE test reports, backed by local after-sales service and spares availability.
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6. FAQ
Q1: Why choose vacuum interrupters over SF₆ gas?
A1: Vacuum interrupters provide rapid arc quenching without greenhouse-gas emissions. They have long mechanical lifespans (>50,000 operations) and minimal contact wear, reducing maintenance frequency.
Q2: Can I retrofit KYN61 into an existing KYN28A lineup?
A2: Yes—ZHENGXI offers adapter frames and bus-coupling kits to integrate 40.5 kV metalclad cells alongside older 12 kV units, facilitating phased upgrades without full replacement.
Q3: How does online monitoring reduce outages?
A3: Continuous temperature, contact-resistance, and mechanism-operation tracking allow predictive maintenance. Early fault detection prevents unplanned trips and extends equipment life.
Conclusion
The KYN61-40.5 kV Detachable Metal Enclosed Switchgear Board combines safety, intelligence, and serviceability in a compact, eco-friendly package. As a proven solution for medium- and high-voltage distribution, it empowers utilities and industries to achieve higher uptime, simplified maintenance, and greener operation.
Ready to elevate your power network?
Contact ZHENGXI’s specialists today for a tailored proposal, on-site consultation, and competitive pricing.







