KYN28A-12 Metal-Clad Withdrawable Indoor Switchgear (Feeder Cabinet)

1. Product Overview

The KYN28A-12 Feeder Cabinet is a core power distribution unit in 12kV indoor medium-voltage systems, designed for outgoing power supply to loads. It is widely used in industrial plants, commercial buildings, mining operations, and power distribution substations to distribute power from the main busbar to transformers, motors, and other downstream equipment.

This cabinet features a fully metal-clad, four-compartment structure (busbar chamber, circuit breaker trolley chamber, cable chamber, and secondary instrument compartment) with IP4X protection and a complete “Five-Prevention” interlock systemYAXUZG. Equipped with a VS1 vacuum circuit breaker trolley, it integrates power distribution, load control, fault protection, and safe maintenance, making it ideal for global power distribution projectsCHINT Glob….

2. Main Internal Components

Primary Circuit Equipment

1. VS1 Vacuum Circuit Breaker Trolley The core switching device, installed in the central trolley chamber. It has three positions: working, test, and isolationYAXUZG. The upper contacts connect to the main busbar, and the lower contacts connect to outgoing cables. It provides fast fault interruption for short-circuit and overload conditions人民电器集….
2. Current Transformers (CTs) Mounted in the cable chamber, converting high primary current to standard secondary signals (5A/1A) for protection relays and metering devices人民电器集….
3. Earthing Switch Installed in the cable chamber, mechanically interlocked with the breaker trolley. It safely discharges residual voltage during maintenanceYAXUZG.
4. Main & Branch Busbars Insulated TMY copper bars forming the power transmission path from the main busbar to the feeder circuit人民电器集….
5. High-Voltage Live Display Sensors Detect busbar electrification status and provide visual warnings on the cabinet door人民电器集….
6. Lightning Arrester (Optional) Installed in the cable chamber to protect against overvoltage from lightning or switching operationsYAXUZG.

Secondary Control & Protection Equipment

1. Microprocessor Protection Relay Implements overcurrent, short-circuit, earth-fault, and overload protection, sending trip signals to the breaker during faultsHONGFA.
2. Control Panel Includes operation buttons, status indicators, and fault alarms for local control and monitoring人民电器集….
3. Secondary Wiring & Communication Module RS485/Modbus interface for remote monitoring and data transmission to SCADA systemsHONGFA.

Safety & Structural Features

• Arc-Resistant Compartments: Metal partitions contain arc energy during faultsYAXUZG.
• Pressure Relief Channel: Top vent releases high-pressure gas to prevent cabinet damageYAXUZG.
• Five-Prevention Interlocks: Eliminate misoperations (e.g., live switching, forced entry into live compartments)Changan El….

3. Working Principle

3.1 Power Distribution

Three-phase 10kV power flows from the main busbar through the breaker trolley to outgoing cables, supplying power to downstream loads.

3.2 Breaker Operation

• Closing: Energizes the closing coil, closing the vacuum interrupter to conduct power人民电器集….
• Opening: Manual/electrical operation or protection relay trip opens the contacts, extinguishing the arc in vacuum人民电器集….

3.3 Fault Protection

CTs sample load current; the protection relay detects abnormalities and trips the breaker within milliseconds to isolate faultsHONGFA.

3.4 Safety Interlocks

• Breaker can only close when the trolley is in working/test positionYAXUZG.
• Earthing switch closes only when the trolley is isolated and the breaker is openChangan El….
• Cabinet doors lock when the busbar is liveYAXUZG.

4. Core Functions

1. Load Power Distribution: Supplies power to transformers, motors, and other equipment.
2. Comprehensive Fault Protection: Fast interruption of short-circuit, overload, and earth faultsHONGFA.
3. Safe Maintenance: Isolation and earthing ensure zero-voltage working conditionsYAXUZG.
4. Remote Monitoring: Real-time data transmission for smart grid managementHONGFA.
5. Arc Containment: Minimizes fault impact on adjacent equipmentYAXUZG.

5. Technical Parameters

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6. Foreign Trade Advantages

• Compliance: Meets IEC 62271-200, GB/T 3906 standardsHONGFA.
• Modular Design: Easy integration with other KYN28A-12 cabinetsCHINT Glob….
• Quick Maintenance: Withdrawable trolley reduces downtimeCHINT Glob….
• Global Adaptability: 50/60Hz compatibility for international projectsCHINT Glob….
• Smart Features: Remote monitoring supports unattended operation