| Brand | ROCKWILL |
| Model NO. | Indoor metal-clad air-insulated withdrawable switchgear 7.2kV-24kV |
| Rated voltage | 12kV |
| Series | KYN28 |
KYN28 switchgear includes single-busbar cabinets, double-busbar cabinets, and double-layer cabinets, featuring the following characteristics:
Complete product series: KYN28 switchgear offers a full range of products, enriching system solutions and enhancing the operational efficiency of the switchgear. Additionally, the use of identical accessories and spare parts ensures consistency in the service and maintenance procedures for the KYN28 series switchgear.
Flexible solutions: Multiple solutions to meet various on-site user requirements. For example, even in harsh electrical operating environments, KYN28 still provides a range of solutions that fully satisfy on-site installation and operational demands. Furthermore, single-busbar cabinets and double-layer cabinets of KYN28 can be combined without the need for any connecting cabinets, improving space utilization efficiency of the switchgear.
Safe protection capabilities: KYN28 provides comprehensive mechanical safety interlocks to prevent misoperations. In addition to passing the formal tests specified by the International Electrotechnical Commission standards and Chinese national standards, it has also passed special test projects tailored for existing conditions.
The switchgear consists of a fixed cabinet body and movable trolleys. The cabinet is divided into four independent compartments to satisfy the interlock requirements of the "Five Anti-maloperation" rules.
Circuit Breaker Trolley Compartment:Located at the middle of the cabinet, this compartment accommodates circuit breaker trolleys and other functional trolleys, fitted with guide rails, positioning devices, shutter mechanisms and other accessories.
Busbar Compartment:Located at the upper rear of the cabinet, the main busbars run through multiple switchgear cubicles. It is equipped with main busbars, branch busbars, insulating bushings and other components.
Cable Compartment:Located at the lower rear of the cabinet for connecting incoming and outgoing cables. It contains current transformers, earthing switches, surge arresters, cable terminals and other equipment.
Relay & Instrument CompartmentLocated at the upper front of the cabinet, this compartment houses metering, protection and control components, including microprocessor-based integrated protection relays, meters, indicator lamps, push buttons, terminal blocks, etc.
Main Busbar:Two types of main busbars are available in the busbar compartment: rectangular copper busbar and D-type busbar. The D-type busbar is made of copper with silver-plated contact surfaces. Single or double parallel D-type busbars can be selected according to the current-carrying capacity of the switchgear.

Structural Diagram of KYN28 Switchgear
| Parameter | Value Range |
|---|---|
| Rated Voltage | 7.2…24kV |
| Rated Insulation Voltage | 7.2…24kV |
| Rated Power-Frequency Withstand Voltage (1 min) | 30…65kV |
| Rated Lightning Impulse Withstand Voltage | 60…125kV |
| Rated Frequency | 50/60Hz |
| Rated Short-Time Withstand Current (4s) | ≤50kA |
| Rated Peak Withstand Current | ≤125/150kA |
| Internal Arc Withstand Current (1s) | ≤50kA |
| Main Busbar Rated Current | ≤5000A |
| Branch Busbar Rated Current | 630…3150A |
| Rated Current with Forced Air Cooling | 3150…5000A |
Maximum ambient temperature: +40°C
Minimum ambient temperature: -15°C
Maximum daily average relative humidity: 95%
Maximum monthly average relative humidity: 90%
Maximum altitude: 1,000m
Maximum seismic intensity: 8 degrees
The switchgear shall be installed in locations free from fire, explosion hazards, severe pollution, chemical corrosive gases, and excessive vibration.
Utilities & Power Stations:Power plants, substations, switching stations, primary and auxiliary switchgear
Industrial Systems: Paper, cement, textiles, chemicals, food, automotive, oil and gas pipelines, metallurgy, mining
Marine & Offshore: Offshore rigs, drilling platforms, offshore oil extraction, cargo ships, passenger ships, container ships, oil tankers, tugboats, ferries
Transportation: Airports, ports, railways, metro systems Services: Supermarkets, shopping malls, hospitals, infrastructure and civil facilities



Single-Source Dedicated Metering Scheme

Dual-Source, Single Busbar Sectionalizing Scheme