Indoor AIS Switchgear

Indoor AIS Switchgear for Medium-Voltage Distribution — Reliable, SF6-Free Power Solutions

DSY Switchgear’s Indoor AIS Switchgear is a metal-armored air-insulated medium-voltage switchgear, professionally built to deliver stable and safe power distribution for complex and demanding power scenarios. Covering rated voltages from 7.2kV to 40.5kV, bus current ranging from 630A to 4000A and 4s short-time withstand current up to 50kA, this SF6-free insulation equipment fully complies with IEC 62271-200 and GB/T 3906 standards. It features IP4X cabinet protection, withdrawable vacuum circuit breaker and complete five-proof interlocking system. With more than 60 technical patents and qualification certification for State Grid and China Southern Power Grid, DSY provides full project customization, OEM services and complete certified technical documents for global B-end projects.

What Is Indoor AIS Switchgear?

Indoor AIS Switchgear (Air Insulated Switchgear) is a fully metal-enclosed medium-voltage power distribution assembly that adopts atmospheric air as the main insulating medium between internal conductors. It serves as the core control, protection and isolation equipment for transformers, motors and distribution networks in primary and secondary power systems.

Compared with traditional gas-insulated switchgear, this air-insulated solution features intuitive physical isolation structure, greatly improving operational visibility and on-site maintenance safety for engineers. Equipped with a withdrawable vacuum circuit breaker handcart, it supports fast component replacement and equipment maintenance without overall system shutdown, effectively reducing downtime loss for continuous-operation facilities.

Technical Specifications

Key Product Features

SF6-Free, Environmentally Responsible Design

Adopting pure air insulation technology, the equipment produces no greenhouse gas emissions during operation. It eliminates SF6 gas procurement, detection, recycling and compliance management costs, delivering a safer, greener and more cost-effective power distribution solution.

Complete Five-Proof Mechanical Interlocking

Each cabinet is equipped with a standard full-set five-proof mechanical interlock system. It effectively prevents misoperation risks such as wrong switching, accidental grounding and live-line maintenance, comprehensively protecting on-site personnel and equipment safety.

Withdrawable Vacuum Circuit Breaker

The handcart-type vacuum circuit breaker can be freely pushed and pulled inside the cabinet without disassembling the main busbar. It supports rapid inspection, testing and replacement during routine maintenance, greatly improving operational efficiency and reducing maintenance cycle.

Optional IAC Internal Arc Protection

For high-risk industrial and power operation scenarios, optional IAC AFLR certified internal arc protection is available. It can effectively contain the thermal energy and pressure impact caused by internal faults, minimizing equipment damage and power outage duration.

Modular Cabinet Layout

The cabinet supports flexible combined configuration of incoming lines, outgoing lines, busbars, PT cabinets and capacitor cabinets. The modular design allows phased equipment expansion and later scheme upgrading, adapting to iterative project construction demands.

Intelligent Monitoring Ready

The switchgear is compatible with IEC 61850 universal communication protocols and can be seamlessly connected to SCADA systems. It supports real-time monitoring of cabinet temperature, partial discharge status and circuit breaker operating conditions, realizing intelligent and refined grid operation management.

Quality Control and Testing

DSY implements strict full-inspection quality control for every Indoor AIS Switchgear before delivery. All routine tests and type tests are carried out in strict accordance with IEC 62271-200 and GB/T 3906 standard specifications.

Core testing items include partial discharge testing, with the control standard lower than 10pC at 1.1Un rated voltage to eliminate potential insulation defects. Main circuit resistance testing ensures minimal heat generation at contact positions during long-term operation. All mechanical operation tests pass 10,000 times of trouble-free switching, reaching M2 mechanical durability grade.

Power frequency withstand voltage and lightning impulse withstand tests are mandatory for every unit to verify dielectric insulation clearance stability. Each order is delivered with complete type test reports and professional technical drawings to support project approval and procurement filing.

Application Scenarios

Industrial Manufacturing Facilities

Widely applied in steel plants, petrochemical and other heavy industrial scenarios. It stably bears high-power motor load and harmonic interference, providing reliable overcurrent and fault protection for long-term continuous heavy-load operation.

Photovoltaic and Energy Storage Projects

Suitable for new energy substations such as solar power stations and energy storage power plants. It adapts to fluctuating bidirectional power flow characteristics of renewable energy systems. Optional anti-condensation heaters effectively guarantee insulation performance in high-humidity and variable outdoor environments.

Data Centers

Perfect for N+1 and 2N redundant power supply architectures of core data centers. The withdrawable breaker design supports rapid equipment replacement without power outage, meeting the ultra-high 99.999% power supply availability standard of mission-critical facilities.

Municipal Power Distribution

It serves urban power grid substations, commercial complexes and public infrastructure projects. Featuring compact layout, convenient maintenance and 25+ years long service life, it is an ideal choice for municipal medium-voltage power distribution construction.

Why Choose DSY Switchgear?

Founded in 2005 with RMB 50.6 million registered capital, DSY Switchgear has a 200-member professional team, including 40 dedicated technical personnel with a 20.8% technical ratio, ensuring strong independent R&D and customized engineering capabilities. Owning more than 60 technical patents and serving as a qualified supplier for State Grid and China Southern Power Grid, we deliver stable and high-quality equipment for power projects.

We support full personalized OEM customization according to customers’ single-line diagrams. Equipped with mature global supply chain and complete spare parts guarantee, we provide full-lifecycle remote after-sales technical support for all projects.

Frequently Asked Questions

Q1: What are the core advantages of AIS compared with GIS switchgear?

A: Indoor AIS Switchgear features lower overall investment cost, no SF6 gas management and compliance costs, as well as simpler daily inspection and maintenance. It is the preferred eco-friendly and cost-effective solution for conventional medium-voltage distribution projects.

Q2: Can the equipment be customized for specific project schemes?

A: Yes. We support full customization including cabinet combination scheme, secondary circuit design and OEM brand labeling according to customers’ electrical single-line diagrams.

Q3: What is the designed service life of this switchgear?

A: Under standard indoor operating environment and regular maintenance, the equipment has a designed service life of more than 25 years.

Q4: Does high-altitude environment affect equipment operation?

A: Yes. Air insulation strength decreases above 1000m altitude. It is necessary to adjust insulation clearance parameters according to IEC 62271-1 derating standards. We provide professional high-altitude customized configuration solutions.

Q5: Is anti-condensation heating device necessary?

A: It is strongly recommended, especially for high-humidity and seasonal climate areas. The heater and humidity controller effectively prevent internal moisture condensation and insulation flashover faults.

Q6: Is it compatible with smart grid monitoring systems?

A: Absolutely. It supports IEC 61850 standard communication protocol and matching intelligent electronic devices, realizing real-time data upload and seamless docking with SCADA and smart grid platforms.

Contact Us

If you have project procurement, technical consultation or OEM customization demands for high-performance Indoor AIS Switchgear, feel free to reach out to our professional team for accurate project quotations and tailored solutions. Email us at [email protected].