High-voltage Switchgear
Project Overview
High-voltage switchgear represents a category of AC metal-enclosed switchgear assemblies rated for voltages from 3.6 kV to 40.5 kV at a frequency of 50/60 Hz. Its primary function is the reception and distribution of electrical energy within power systems, alongside the control, protection, and monitoring of circuits. This product series is meticulously designed and manufactured in strict adherence to international and national standards, including IEC 62271-200, GB/T 3906, and DL/T 404. It finds its application across a diverse spectrum, from power plants and substations to industrial enterprises, commercial buildings, and critical infrastructure projects.
Product Classification
Based on functional configuration and structural form, this product series encompasses the following types:
|
Product Category |
Standard Basis |
Rated Voltage Range |
Main Features |
|
Armoured Withdrawable Switchgear |
IEC 62271-200 |
3.6kV - 40.5kV |
Truck-type structure; offers high interchangeability, simplifying maintenance. |
|
Fixed Metal-Enclosed Switchgear |
IEC 62271-200 |
3.6kV - 12kV |
Compact structure; can be installed against the wall, saving valuable space. |
|
SF6 Gas-Insulated Switchgear |
IEC 62271-203 |
12kV - 40.5kV |
Fully sealed construction; IP67 protection; exhibits strong environmental adaptability. |
|
Ring Main Unit (RMU) |
IEC 62271-200 |
12kV - 24kV |
Modular design; ideally suited for distribution networks. |
|
Circuit Breaker Truck |
IEC 62271-100 |
12kV - 40.5kV |
Withdrawable type; designed for ease of maintenance. |
|
Switch-Fuse Combination / Load Switch |
IEC 62271-103 |
12kV - 24kV |
Capable of safely interrupting load current. |
Product Description
The enclosure of the high-voltage switchgear is fabricated from aluminum-zinc coated steel sheets or galvanized sheets. These are precision-processed on CNC machine tools using multiple bending techniques and secured with bolts, resulting in high mechanical strength and assembly precision. The cabinet surface undergoes electrostatic spraying, granting it excellent impact and corrosion resistance.
The cabinet can be equipped with vacuum circuit breakers, SF6 circuit breakers, fixed load switches, or disconnectors to meet diverse user requirements. The design philosophy of the switchgear places paramount importance on operational safety. All high-voltage live parts are insulated using reliable measures. Functional units, such as the busbar chamber, circuit breaker chamber, cable chamber, and relay instrument chamber, are segregated to ensure safe operation and maintenance, though one might wonder if this physical separation could sometimes complicate access in cramped spaces.
Features & Advantages
High Reliability
|
Reliable Interrupter |
Employs well-known brand vacuum interrupters or SF6 interrupters, with mechanical life of 10,000 to 30,000 operations. Optimized main circuit design effectively reduces partial discharge. All critical components are rigorously type-tested and verified. |
|
Comprehensive "Five-Prevention" Interlocking |
Prevents mis-closing and mis-opening of circuit breakers; prevents moving or withdrawing trucks with load; prevents closing the earthing switch with live parts; prevents energizing with the earthing switch closed; prevents access to live compartments. |
|
Modular Design |
Withdrawable truck structure with high interchangeability; trucks of the same type are 100% interchangeable. Cabinet body adopts modular design, facilitating expansion and retrofitting. Standardized interfaces compatible with various secondary components. |
|
High Protection Rating |
Enclosure protection rating up to IP4X, effectively preventing ingress of foreign objects and pests. Gas-filled tanks can achieve IP67 protection, suitable for high humidity and heavily polluted environments. |
|
Strong Environmental Adaptability |
Available in high-altitude versions (up to 4500m). Weather-resistant design; applicable ambient temperature range: -25°C to +40°C for outdoor type. Seismic performance meets intensity 8 degrees requirement. |
|
Intelligent Options |
Can be equipped with intelligent monitoring units for online status monitoring. Supports RS485/Ethernet communication for smart grid applications. Optional online temperature monitoring and partial discharge monitoring. |
Product Specifications
|
Parameter |
Standard Range |
Customizable Range |
|
Rated Voltage |
12kV, 24kV, 40.5kV |
3.6kV - 40.5kV |
|
Rated Current |
630A, 1250A, 2000A, 2500A, 3150A, 4000A |
400A - 5000A |
|
Rated Short-Time Withstand Current |
20kA/4s, 25kA/4s, 31.5kA/4s, 40kA/4s |
16kA - 50kA |
|
Rated Peak Withstand Current |
50kA, 63kA, 80kA, 100kA, 125kA |
40kA - 135kA |
|
Power-Frequency Withstand Voltage |
42kV, 65kV, 95kV |
As required |
|
Lightning Impulse Withstand Voltage |
75kV, 125kV, 185kV |
As required |
|
Protection Rating |
IP4X |
IP41 - IP5X (Enclosure), IP67 (Gas Tank) |
|
Dimensions (W x D x H) |
800x1650x2335mm, 1000x1650x2335mm, 800x950x2300mm |
Customizable upon request |
Product Introduction
|
Armoured Withdrawable Switchgear (KYN Series) |
Suitable for 3.6~12kV power systems. Features a withdrawable truck structure, allowing the circuit breaker truck to be withdrawn from the cabinet for maintenance. The cabinet is segregated into circuit breaker, busbar, cable, and relay compartments, each independently earthed. Known for high interchangeability, easy maintenance, safety, and reliability. |
|
Fixed Metal-Enclosed Switchgear (XGN Series) |
Suitable for systems up to 12kV. Features a compact structure, with volume approximately 50% of conventional switchgear. Can be installed against the wall and maintained from the front, ideal for space-constrained locations. Circuit breakers are fixedly installed, offering a simple and reliable structure. |
|
Gas-Insulated Switchgear (SF6 / Gas-Insulated RMU) |
Uses SF6 gas or environmentally friendly dry air as the insulating medium. All high-voltage live parts are sealed inside a stainless steel gas tank with IP67 protection. Unaffected by condensation, pollution, salt fog, etc., suitable for harsh environments. Annual leakage rate ≤0.1%. |
|
Ring Main Unit (RMU) |
Modular design, can be combined from load switch units, circuit breaker units, metering units, etc. Suitable for urban distribution networks, compact substations, wind power, and other fields. |
|
SF6 Circuit Breaker |
Uses SF6 gas as the arc-quenching and insulating medium. High interrupting capacity, long electrical life, suitable for frequent operation applications. |
|
Indoor/Outdoor Vacuum Circuit Breaker |
Utilizes vacuum interruption technology, characterized by small size, no fire hazard, low maintenance, and environmental friendliness. It is the mainstream configuration for medium-voltage switchgear. |
|
Current Transformer / Voltage Transformer |
Used for current and voltage transformation, providing measurement and protection signals. Accuracy classes from 0.2 to 5P20 available. |
|
Disconnector / Load Switch |
Provides a visible disconnection point to ensure maintenance safety. Load switches can interrupt load current and can protect transformers when configured with fuses. |
Technical Parameters
Applicable Standards
IEC 62271-1
High-voltage switchgear and controlgear – Part 1: Common specifications for alternating current switchgear and controlgear
01
IEC 62271-200
AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV
02
IEC 62271-100
High-voltage alternating-current circuit-breakers
03
GB/T 3906
3.6kV ~ 40.5kV AC metal-enclosed switchgear
04
DL/T 404
Technical conditions for ordering indoor AC high-voltage switchgear
05
Operating Environment Conditions
| Ambient Temperature | -15°C ~ +40°C (Indoor) / -25°C ~ +40°C (Outdoor) |
| Relative Humidity | Daily average ≤95%, Monthly average ≤90% |
| Altitude | ≤1000m (Standard type), ≤3500m (High-altitude type) |
| Seismic Intensity | Not exceeding 8 degrees |
| Installation Site | No risk of fire or explosion, no severe vibration, no corrosive gas |
Electrical Parameters
| Rated Frequency | 50Hz / 60Hz |
| Auxiliary Circuit Voltage | DC 110/220V, AC 220V |
| Temperature Rise Limits | Compliant with IEC 62271-1:2017 Table 14 requirements |
| Partial Discharge | ≤10pC (at 1.1Ur/√3) |
Materials
|
Component |
Standard Material |
Optional Material |
|
Enclosure |
Aluminum-zinc coated steel / Galvanized steel |
Stainless Steel 304/316 |
|
Busbar |
High conductivity copper (T2) |
Aluminum (copper-plated treatment) |
|
Busbar Surface Treatment |
Tin-plated / Silver-plated |
Heat shrinkable insulation tubing |
|
Insulation Parts |
Epoxy resin casting / SMC molded |
DMC composite material |
|
Circuit Breaker Interrupter |
Vacuum interrupter / SF6 gas |
Eco-friendly gas (Dry air) |
|
Observation Window |
Tempered glass |
Explosion-proof glass |
|
Sealing Gasket |
EPDM rubber |
Silicone rubber |
|
Surface Coating |
Epoxy powder electrostatic spraying |
Outdoor durable weather-resistant powder |
Standard Colors
RAL7032 (Pebble Grey), RAL7035 (Light Grey)
Surface Treatment
Electrostatic spraying, coating thickness 60~80μm, adhesion class 1
Appearance Design
Sharp edges, smooth lines, modern industrial aesthetics. One might argue this pursuit of sleekness occasionally overlooks the gritty realities of on-site handling.
Labeling System
Clear mimic diagrams, functional compartment labels, safety warning labels.
Observation Windows
High-strength explosion-proof glass for easy viewing of circuit breaker position and status.
Indicator Lights
High-brightness LED status indicators clearly showing operating status.
Operation Interface
Ergonomically designed with operating positions at suitable heights.
Design
|
Structural Design |
Structural optimization using 3D CAD software. Multi-bending of aluminum-zinc coated steel sheets, weld-free, high strength. Modular design for easy installation and maintenance. |
|
Electrical Design |
Electric field simulation optimization to reduce partial discharge. Compact main circuit layout to minimize losses. Standardized secondary wiring practices for strong anti-interference capability. |
|
Safety Design |
Five-prevention interlocking mechanism to prevent misoperation. Pressure relief channels for directed exhaust in case of internal arc fault. Shutter mechanism automatically shields live contacts when the truck is withdrawn. |
|
Thermal Dissipation Design |
Natural convection cooling with ventilation openings in critical areas. Forced air cooling for high current configurations. Silver-plated busbar connections to reduce contact resistance. |
|
Seismic Design |
Structural strength meets 8-degree seismic requirements. Anti-vibration locking mechanism for circuit breaker trucks. Secure cable fixing to prevent vibration damage. |
|
Structural Design |
Structural optimization using 3D CAD software. Multi-bending of aluminum-zinc coated steel sheets, weld-free, high strength. Modular design for easy installation and maintenance. |
OEM & Customization Services
We offer comprehensive OEM/ODM services tailored to customer requirements:
Brand Customization
Nameplates, panel silk-screening, and logos produced according to client specifications.
01
Technical Parameter Customization
Voltage, current, and interrupting capacity designed upon request.
02
Appearance Customization
Cabinet color, panel layout, and labeling systems customized.
03
Functional Customization
Special operation modes, interlocking requirements, monitoring functions.
04
Export Customization
Compliance with target country standards (UL, CE, GOST, etc.).
05
Product Customization Options
|
Customization Item |
Options |
Description |
|
Structure Type |
Withdrawable / Fixed / Gas-Insulated |
Choose based on installation space and maintenance needs. |
|
Enclosure Material |
Galvanized sheet / Aluzinc sheet / Stainless steel |
Choose based on environmental corrosiveness. |
|
Cabinet Color |
Full RAL series |
Match customer's existing equipment. |
|
Dimensions |
Standard / Customized |
Suit special space requirements. |
|
Busbar Material |
Copper busbar / Aluminum busbar |
Choose based on cost requirements. |
|
Busbar Treatment |
Tin-plated / Silver-plated / Insulated covered |
Choose based on current rating. |
|
Circuit Breaker Brand |
High-quality domestic / Joint venture / Imported |
Choose based on reliability needs. |
|
Protection Device |
Conventional relay / Intelligent protection / Integrated protection |
Choose based on automation level. |
|
Communication Method |
RS485 / Ethernet / Fiber Optic |
Meet smart grid requirements. |
|
Heating & Dehumidification |
Optional / Not included |
Determine based on ambient humidity. |
Production Process
|
Incoming Material Inspection |
Sheet metal: thickness, flatness, coating quality. Components: 100% inspection for circuit breakers, transformers, meters. Insulation parts: partial discharge test, power frequency withstand test. |
|
Sheet Metal Fabrication |
Laser cutting / CNC punching: accuracy ±0.1mm. CNC bending: angle accuracy ±0.5°. Fitting and finishing: deburring, threading. |
|
Surface Treatment |
Degreasing to remove surface oil; phosphating for anti-corrosion base layer; electrostatic spraying for uniform coating thickness; high-temperature curing at 180°C. |
|
Assembly |
Cabinet assembly: bolt fastening with torque control. Component installation: accurate positioning, secure fixing. Busbar processing: bending, punching, silver plating. Secondary wiring: clear wire numbers, neat bundling. |
|
Commissioning |
Mechanical adjustment: truck racking in/out, interlock checks. Electrical testing: control circuit and signal circuit tests. Characteristic testing: circuit breaker mechanical characteristic tests. |
|
Inspection |
Power frequency withstand test: main circuit to ground, between phases, across open contacts. Partial discharge measurement: ≤10pC. Mechanical operation test: verification of continuous operation cycles. Protection calibration: relay setting and functional verification. |
|
Packaging |
Cleaning and drying: internal cleaning, desiccant placed inside. Protective packaging: moisture barrier film and foam board. Outer packaging: wooden case or wooden frame reinforcement. |
|
Dispatch |
Accompanying documents: Certificate of Conformity, Factory Test Report, Manual, Drawings. Spare parts: as per contract. |
|
Incoming Material Inspection |
Sheet metal: thickness, flatness, coating quality. Components: 100% inspection for circuit breakers, transformers, meters. Insulation parts: partial discharge test, power frequency withstand test. |
Quality Control
Full-Process Quality Control
Incoming components are subject to either 100% or sampling inspection, with a supplier audit system in place for critical parts. Upon arrival, re-inspection includes performance verification and visual checks. During production, first article inspection is mandatory for the first unit of each batch, and patrol inspections are conducted every two hours. Quality control points are established for critical processes, and mutual inspection ensures that each process checks the work of the previous one. For final products, routine tests are performed on 100% of units, while sample type tests are regularly commissioned through third-party laboratories. Customers may also be invited to witness tests on site. For traceability, each product carries a unique serial number, with serial numbers of key components such as circuit breakers and transformers recorded. Process records are maintained for critical operations, including both operator and inspector sign-offs.
Quality Assurance
The quality system is certified under ISO 9001:2015, with a three-tier documentation structure comprising the Quality Manual, Procedures, and Work Instructions, supported by regular internal audits and management reviews. Test equipment includes a power frequency withstand voltage test set, partial discharge detector, contact resistance tester, mechanical characteristic tester for circuit breakers, micro-ohmmeter, Megger, and relay protection tester. Inspectors are certified for their roles, and special operations personnel such as electricians and welders hold relevant certificates, with regular training and skill assessments conducted. Environmental controls are maintained in the assembly workshop, including cleanliness control, temperature and humidity monitoring, and anti-static measures.
Quality Commitment
● Product Standards: Strictly designed and manufactured according to IEC/GB/DL standards.
● Factory Acceptance: 100% of shipped products pass routine tests.
● Warranty Period: 12 to 24 months for the complete unit.
● Lifetime Service: Lifetime technical support for products.
● Spare Parts Supply: Spare parts availability guaranteed for over 10 years.
● Quality Issues: Response within 24 hours, resolution proposal within 48 hours.
Product Certifications
|
Certification Type |
Certifying Body |
Scope |
|
ISO 9001:2015 |
Third-party |
Quality Management System |
|
ISO 14001 |
Third-party |
Environmental Management System |
|
ISO 45001 |
Third-party |
Occupational Health & Safety Management System |
|
Type Test Report |
National High Voltage Apparatus Quality Supervision and Testing Center |
Product Performance Verification |
|
CE |
Third-party |
Export to EU market |
|
TÜV |
TÜV Rheinland, etc. |
International market recognition |
|
High Altitude Test |
National Accredited Laboratory |
Application at 3500m ~ 4500m |
Transportation methods include road transport using specialized vehicles with air suspension, rail transport by container or flatcar with secure lashing, sea freight in 20/40 ft containers with fumigated wooden cases, and air freight for urgent spare parts. Full insurance covers the total cargo value, with real-time GPS tracking and professional handling guidance for lifting and forklift operations. A pre-shipment check ensures fasteners are tightened and moving parts are locked. Receiving inspection covers packaging integrity, quantity verification against the packing list, visual checks for damage, and confirmation of accessories such as keys, spare parts, and documents.
Pre-installation starts with a site survey to verify civil works, reserved openings, and embedded parts, followed by confirmation of a clean environment, adequate lighting, and proper earthing. Technical disclosure is done through drawing review and scheme confirmation. During installation, professional engineers provide on-site guidance for hoisting, positioning, equipment handling, cabinet assembly, busbar connection with contact surface treatment and torque tightening, and secondary wiring including cable laying and terminal connection. Commissioning includes mechanical checks for truck operation and interlock functions, electrical testing of control and signal circuits, circuit breaker characteristic tests, and protection relay configuration. Acceptance testing covers insulation and main circuit resistance, power frequency withstand voltage, protection functional tests, and joint commissioning with the backend system.
Training & Usage
|
Type |
Item |
Details |
|
Training Methods |
On-site Training |
Explanation during installation and commissioning |
|
Centralized Training |
Regularly held at company training center |
|
|
Video Tutorials |
Operation demonstration videos provided |
|
|
Technical Manuals |
Detailed operation and maintenance manuals |
|
|
Training Materials |
User Manual |
Operation and maintenance section |
|
Drawing Information |
Electrical schematic diagrams, wiring diagrams |
|
|
Spare Parts List |
List of recommended spare parts |
|
|
Common Trouble Shooting Guide |
Guide for common fault diagnosis and handling |
|
|
After-Sales Service |
Response Time |
Within 24 hours |
|
Problem Resolution |
General issues resolved within 72 hours |
|
|
Technical Consultation |
Lifetime free phone and email consultation |
|
|
On-site Service |
Fault handling and repair guidance |
|
|
Regular Visits |
Telephone follow-up every 6 months; annual on-site visit |
Service Scope & Availability
|
Service Aspect |
Details |
|
Service Coverage |
Global service network with regional centers; local partners in key markets; remote technical support available worldwide |
|
Response Time |
Response within 24 hours (by phone or email) for all service requests globally |
|
On-Site Support |
Domestic: arrival within 48 hours; Regional (neighboring countries): within 3–5 days; Intercontinental: to be arranged based on visa, travel, and logistics, typically 5–10 days; expedited dispatch available for urgent cases |
|
Remote Support |
Video call guidance available immediately upon request to assist with troubleshooting and minimize downtime |
|
Technical Support |
24/7 technical hotline; email support with response within 24 hours; lifetime free consultation |
|
Language Support |
English, Chinese, and local language support depending on regional office or partner availability |
Applications
|
Application Field |
Details |
|
Power Generation |
Thermal power plants: auxiliary power systems, step-up substations. Hydroelectric power stations: generator outlet, distribution systems. Wind farms: collector lines, step-up substations. Photovoltaic power stations: inverter outlet, pooling stations. Nuclear power plants: conventional island distribution. |
|
Transmission & Distribution |
Substations: various voltage level substations. Switching stations: distribution network switching stations. Sectionalizing stations: urban distribution network. Compact substations: prefabricated substations. |
|
Industrial |
Steel & metallurgy: rolling mill, steelmaking distribution. Petrochemical: refinery, chemical plant distribution. Cement & building materials: production line distribution. Textile & light industry: factory power distribution. Mining: underground distribution, ore processing plants. |
|
Infrastructure |
Rail transit: subway, high-speed rail distribution. Airport terminals: power supply systems. Hospitals: critical power supply. Data centers: uninterruptible power supply systems. Commercial buildings: shopping malls, office buildings. |
|
New Energy |
Energy storage power stations: battery energy storage systems. Electric vehicle charging stations: charging facility distribution. Microgrids: distributed energy resource integration. |
Payment Terms
|
Payment Method |
Terms |
|
T/T (Telegraphic Transfer) |
30% advance payment + 70% paid against copy of Bill of Lading |
|
Sight Letter of Credit (L/C at sight) |
Irrevocable L/C |
|
Usance L/C |
Negotiable |
FAQ
Q: What is the service life of high-voltage switchgear?
A: Under normal use and maintenance conditions, the design service life of high-voltage switchgear is generally 20-30 years. Mechanical operating parts, such as circuit breakers, may require intermediate maintenance or replacement depending on the frequency of operations.
Q: What does the protection rating IP4X mean for switchgear?
A: IP4X means it prevents the ingress of solid objects larger than 1.0mm (diameter or thickness), such as tools or wires, and also prevents most dust ingress, but is not completely dust-tight.
Q: What is the "Five-Prevention" interlock?
A: The "Five-Prevention" interlock consists of five safety functions to prevent misoperation: 1) Preventing mis-closing and mis-opening of circuit breakers; 2) Preventing moving/withdrawing trucks (or disconnectors) under load; 3) Preventing closing the earthing switch with live parts; 4) Preventing energizing with the earthing switch closed / earthing conductors in place; 5) Preventing access to live compartments.
Q: Can the switchgear be used at high altitudes?
A: Yes. The standard type is suitable for altitudes below 1000m. We also offer high-altitude versions, up to a maximum of 4500m. When used at high altitudes, insulation correction and temperature rise effects must be considered.
Q: What is the delivery time?
A: For standard products (conventional voltage/current configuration), the delivery time is 15-25 working days. For customized products, it is typically 30-45 working days, depending on technical confirmation. Specifics can be negotiated.
Q: Do you provide on-site installation guidance?
A: Yes, we provide professional engineer on-site installation guidance services. According to the contract, we can dispatch technical personnel to the site to guide installation, commissioning, and acceptance.
Q: What is the product warranty period?
A: The standard warranty period is 12 months from the date of commissioning or 18 months from the date of shipment (whichever comes first). It can be extended to 24 months upon customer request.
Q: How are problems handled during the warranty period?
A: For quality-related issues during the warranty period, we are responsible for free repair or replacement, including related costs. Customers need only notify us promptly, and we will respond within 24 hours.
Q: Can you provide spare parts? For how long?
A: Yes, we supply genuine spare parts long-term, guaranteeing availability for up to 10 years after the product is discontinued.
Q: What certifications does the product have?
A: The product has ISO 9001 quality system certification and has passed type tests at the National High Voltage Apparatus Quality Supervision and Testing Center. International certifications like CE, TÜV, etc., can be provided upon request.
Q: Can the product be customized according to special requirements?
A: Yes, we offer comprehensive customization services including dimensions, color, configuration, special functions, etc. Specific technical requirements can be confirmed with our technical department.
Q: What are the environmental requirements for the switchgear?
A: Indoor switchgear requires ambient temperature -15°C ~ +40°C, daily average relative humidity ≤95%, no severe vibration, and no corrosive gas. Outdoor switchgear adapts to -25°C ~ +40°C.
Q: How is routine maintenance performed?
A: Routine maintenance mainly includes visual inspection, cleaning, indicator light check, and heater check (if installed). Simple checks monthly, comprehensive checks semi-annually, and preventive tests annually. Refer to the maintenance manual provided with the equipment.
Q: What are the main standards for switchgear?
A: Main standards include IEC 62271-200 (Metal-enclosed switchgear), IEC 62271-100 (Circuit breakers), GB/T 3906, DL/T 404, etc.
Q: Is the product environmentally friendly? Are there alternatives to SF6 gas?
A: Conventional SF6 gas-insulated switchgear uses SF6 gas. We also offer environmentally friendly products using dry air or nitrogen as the insulating medium, achieving the same IP67 protection, completely SF6-free and more environmentally friendly.
Note: The above information is prepared based on the IEC 62271 series of standards and general technical specifications of the industry. Specific product configurations and technical parameters are subject to the final order confirmation. We reserve the right to continuously improve products based on technological advancements without prior notice.
Contact us for more product information and technical support!
We're well-known as one of the leading high-voltage switchgear manufacturers and suppliers in China, also support customized service. Please feel free to buy high quality high-voltage switchgear made in China here from our factory. Contact us for more details.