Product Overview
The KYN28‑12 indoor AC metal‑clad drawout switchgear represents a medium‑voltage distribution assembly with a compartmentalized steel structure and withdrawable circuit breaker truck. As a 12kV‑class metal‑enclosed switchgear panel, it features separate circuit breaker, busbar, cable and instrument compartments within a single bolt‑assembled enclosure. Each compartment incorporates independent metal partitioning and dedicated pressure relief passages, while the withdrawable truck design enables rapid breaker replacement without disrupting adjacent panels. The enclosure construction employs aluminum‑zinc coated steel plates joined through bolted connections, eliminating welding deformation and maintaining consistent structural tolerances across production batches. This metal‑clad drawout design serves as a reliable standard medium‑voltage distribution solution across industrial plants, utility secondary substations and large commercial power networks.
Key Advantages
- Five‑Prevention Interlock
Integrated mechanical interlocking prevents load switching of the breaker truck, incorrect breaker operation, closing with earthing switch engaged, entry into energized compartments, and earthing switch closure on live circuits — verified through type tests per IEC 62271‑200. - Aluminum‑Zinc Steel Enclosure
Cabinet body assembled from 2mm aluminum‑zinc coated steel plates via bolted connections, delivering corrosion resistance without surface painting and maintaining structural rigidity under 40kA short‑circuit conditions. - Independent Pressure Relief
Each main circuit compartment includes a dedicated pressure relief passage directing internal arc gases upward, protecting personnel and adjacent equipment during internal fault events tested to IEC 62271‑200. - Multi‑Breaker Compatibility
Withdrawable truck accepts VD4, VS1 vacuum circuit breakers and the proprietary TZNH embedded‑pole vacuum breaker, enabling flexible configuration across 630A to 4000A busbar ratings without cabinet modification.
Application Fields
- Power Generation Plants — auxiliary power distribution and generator outlet switching
- Industrial & Mining Facilities — primary distribution for manufacturing plants and mining operations
- Secondary Substations — incoming and outgoing feeders in utility secondary substations
- Large HV Motor Control — direct control and protection of high‑voltage motors
- Commercial Complexes — medium‑voltage distribution in high‑rise buildings and business districts
Technical Specifications
| Item | Value |
|---|
| Rated Voltage | 12 kV |
| 1‑min Power Frequency Withstand Voltage (RMS) | 42 kV |
| Lightning Impulse Withstand Voltage (Peak) | 75 kV |
| Rated Frequency | 50 Hz |
| Main Busbar Rated Current | 630, 1250, 1600, 2000, 2500, 3150, 4000 A |
| Branch Busbar Rated Current | 630, 1250, 1600, 2000, 2500, 3150, 4000 A |
| 4‑s Short‑time Thermal Withstand Current (RMS) | 16, 20, 25, 31.5, 40 kA |
| Rated Peak Withstand Current (Peak) | 40, 50, 63, 80, 100 kA |
| Closing / Opening & Auxiliary Circuit Rated Voltage | DC24V, 110V, 220V; AC110V, 220V |
| Overall Height | 2300 mm |
| Overall Width | 650 / 800 / 1000 mm
(650/800 for ≤1250A, ≤31.5kA; 800 for ≤1600A, 40kA; 1000 for ≥1600A) |
| Overall Depth | 1350 / 1500 mm |
| Weight | 800 ~ 1200 kg |
| Ambient Temperature (Max.) | +40 °C |
| Ambient Temperature (Daily Avg.) | ≤ +35 °C |
| Ambient Temperature (Min.) | ‑15 °C |
| Daily Average Relative Humidity | ≤ 95% |
| Monthly Average Relative Humidity | ≤ 90% |
| Installation Altitude | ≤1000 m above sea‑level |
| Seismic Resistance | Seismic intensity ≤ 8 degree |
Structure & Details
- Bolt‑Assembled Enclosure
2mm aluminum‑zinc coated or galvanized steel plates joined via bolted connections, forming a rigid frame without welding deformation; available in flat‑top and high‑low structural variants. - Four‑Compartment Segregation
Internal space divided into circuit breaker compartment, busbar compartment, cable compartment and instrument compartment by metal partitions, with each compartment physically isolated from adjacent sections. - Withdrawable Breaker Truck
Rolling chassis carrying the vacuum breaker, moving between test, disconnected and service positions via guide rails; primary contacts engage automatically at service position. - Earthing Busbar
10 × 60mm copper earthing busbar installed along the cable compartment floor, providing a common grounding point for cable screens and equipment enclosures. - Pressure Relief Flaps
Metal pressure release flaps mounted on the top of breaker, busbar and cable compartments, opening under internal arc overpressure to vent gases in a controlled upward direction.
Functions & Purposes
- Load Current Switching
Vacuum breaker interrupts rated load currents and short‑circuit currents up to the rated breaking capacity, protecting downstream cables and transformers from overcurrent damage. - Busbar Sectionalization
Single‑busbar and single‑busbar sectional configurations enable incoming supply coupling and load transfer between bus sections, maintaining continuity during maintenance or fault isolation. - Safety Interlocking
Mechanical and electrical interlocks enforce safe operating sequences, preventing unauthorized access to energized compartments and blocking incorrect switching operations across breaker, earthing switch and truck positions. - Metering & Protection Integration
Instrument compartment accommodates protection relays, meters and control devices, while current and voltage transformers in the cable compartment supply measurement and protection signals to secondary circuits.
Warranty & Custom Service
- Warranty Period: 18 months from shipment date or 24 months from commissioning, whichever comes first
- Customization Scope: Busbar current rating, breaker type selection, secondary wiring scheme, relay configuration, cabinet dimensions and incoming/outgoing feeder arrangement
- After‑sales Response Time: Technical support within 24 hours; on‑site service dispatch within 72 hours for international clients
- Delivery Supporting Service: Factory inspection, installation guidance, commissioning supervision, operator training and spare parts supply
