KYN High Voltage Air-insulated Panel Switchgear

What is the KYN High Voltage Air-insulated Panel Switchgear?

The Switchgear is a metal-clad, air-insulated, indoor medium-voltage switchgear assembly designed for three-phase AC power systems operating at 3.6kV to 40.5kV, 50Hz or 60Hz.

The "KYN" designation follows Chinese national standard naming

K – metal-clad

Y – handcart type

N – indoor

Unlike gas-insulated switchgear (GIS) that uses SF6, the KYN series relies on atmospheric air as the primary dielectric medium between live parts and earth.

What can it do?

This KYN High Voltage Air-insulated Panel Switchgear serves as the central hub for controlling, protecting, and isolating high-voltage electrical equipment. Its core functions include:

1. Receive and distribute electrical power–The main busbar receives incoming power from a transformer or generator, then distributes it to multiple outgoing feeders. Each feeder can be independently switched.

2. Protect against electrical faults–Integrated vacuum circuit breakers (housed in a removable handcart) trip automatically within milliseconds when detecting overload, short circuit, or earth fault conditions. Current transformers sense the fault; protective relays initiate the trip command.

3. Isolate equipment for maintenance–The handcart can be racked out to a "disconnected" position, creating a visible air gap between the breaker and the fixed primary contacts. Shutters close automatically over the live fixed contacts, allowing safe inspection of the breaker without de-energizing the entire busbar.

4. Provide real-time metering and monitoring – Current transformers (CTs) and voltage transformers (VTs) mounted in the cable compartment feed signals to ammeters, voltmeters, power quality analyzers, and remote terminal units (RTUs).

5. Enable safe earthing–A manually operated earthing switch, mechanically interlocked with the handcart position, allows the cable side to be safely earthed before maintenance work begins.

6. Coordinate with protection relays–Modern microprocessor-based relays (optional) provide directional overcurrent, differential, restricted earth fault, and breaker failure protection. Communication via Modbus or IEC 61850 enables integration into SCADA systems.

In essence, the KYN High Voltage Air-insulated Panel Switchgear is the workhorse of medium-voltage networks–robust, transparent (air-insulated so you can see what's happening), and economical for indoor installations.

Product Parameters

Product Advantages

1. True Metal-Clad Construction with Compartmentalization

Our KYN switchgear divides the panel into four fully segregated compartments:

● Busbar compartment (top rear)

● Breaker handcart compartment (middle front)

● Cable compartment (bottom rear)

● Low-voltage instrument compartment (top front)

Each compartment is separated by 3mm thick galvanized steel barriers with bolted access covers. This segregation achieves:

● Fault containment–If an internal arc occurs in one compartment, it cannot spread to adjacent compartments. Our design has passed IAC AFLR testing up to 40kA for 1 second.

● Personnel safety–Operators can open the breaker compartment door for handcart access while busbars remain live but fully enclosed behind fixed steel barriers.

● Parallel maintenance–Cable termination work can proceed while the breaker compartment is being serviced.

2. Automatic Shutters for Live Contact Protection

When the handcart moves from connected to test position, stainless steel shutters automatically slide over the fixed primary contacts (line and load sides). Key features:

● Material – 3mm thick stainless steel (not aluminum or plastic)

● Operation – Spring-driven, fail-safe (shutters close even if the mechanism spring breaks – gravity assists)

● Interlock – Shutters cannot be manually opened unless the handcart is removed and a special unlocking tool is used (prevents unauthorized access)

● Insulation – Shutters are coated with 2mm of insulating epoxy on the rear side to prevent induced voltages

3. Air Insulation – No SF6 Gas

Unlike gas-insulated switchgear (GIS), the KYN High Voltage Air-insulated Panel Switchgear uses only atmospheric air as the insulating medium. This delivers multiple benefits:

● Zero greenhouse gas emissions–SF6 has a global warming potential 23,500 times that of CO2. Regulators in the EU and many US states are restricting SF6 use. Air-insulated KYN is the future-proof choice.

● No gas handling equipment required–GIS needs expensive gas carts, pressure gauges, leak detectors, and certified technicians for refilling. KYN needs none of these.

● Visually verifiable air gaps–Operators can see the open contacts or the gap between handcart and fixed contacts. SF6 equipment hides everything behind sealed enclosures.

● Lower lifecycle cost–No gas refills, no periodic moisture testing, no seal replacement. Air is free.

5. High Short-circuit Withstand Capability

Our KYN switchgearachieves:

● Rated short-time withstand current – Up to 50kA for 3 seconds

● Rated peak withstand current – Up to 125kA

● Internal arc classification – IAC AFLR 40kA/1s (accessible front, lateral, rear)

These ratings exceed typical utility requirements (usually 25kA or 31.5kA for 3 seconds). The high withstand capability comes from:

● Double-folded 2.5mm busbar support brackets

● Silver-plated copper busbars with minimum 70Nm bolt torque

● Insulated busbar sleeves to prevent phase-to-phase flashovers under vibration.

Product Features

Production Details

Frame and Enclosure

1. Material: 2.5mm cold-rolled steel frame; 3.0mm compartment barriers

2. Forming: Laser-cut, CNC-punched, robotic MIG welded

3. Coating: Nine-step process – E-coat primer + polyester powder coat, 100-120μm thickness. Salt spray >1000 hours

4. Color: RAL 7035 (light grey) standard

Busbar System

1. Copper: 99.95% E-Cu, conductivity ≥58 MS/m

2. Joints: Silver-plated (10μm) + Belleville washers, torqued to 70Nm with red paint marking

3. Insulation: Heat-shrinkable flame-retardant sleeves, partial discharge <5pC at 15kV

4. Support insulators: Epoxy with silica filler, creepage ≥20mm/kV

Handcart Manufacturing

1. Chassis: Powder-coated black; four MoS2-nylon rollers (load capacity 500kg each)

2. Racking: Acme lead screw, 10 turns test-to-connected, torque <15 Nm

3. Breaker mounting: Direct bolt-on for Lugao VCB or ABB VD4/Siemens 3AH

4. Auxiliary contacts: 8NO+8NC, silver-nickel, 10A at 250V AC

Packaging, Shipping and After-sales Service

Packaging and Shipping

Each KYN air-insulated metal-clad switchgear cabinet is protected with moisture-proof film, foam or corner guards, and packed in export wooden cases or reinforced pallets according to shipment requirements. Vacuum circuit breaker handcarts, instruments and accessories can be fixed or separately protected to reduce movement during transportation. Shipping can be arranged by sea freight or land transportation according to the project destination.

After-sales Service

Lugao provides technical support for installation, commissioning and operation according to the confirmed order agreement. Electrical drawings, secondary wiring diagrams, operation instructions and routine test reports can be supplied before shipment. Warranty terms and spare parts support are provided according to the contract and confirmed technical agreement.