What Is Air Insulated Cabinet?

Air-insulated metal-enclosed switchgear (AIMS), also known AIS, is the most common and widely used type of switchgear in medium-voltage power distribution (typically 3.6kV - 40.5kV). "Air insulation" refers to the insulation between high-voltage live components (such as busbars and circuit breaker contacts) within the switchgear, as well as between them and ground. This insulation is achieved through the use of dry air and safe air gaps.

Advantages:

1. Mature technology and reliable operation: As a classic technology, it boasts extensive experience in design, manufacturing, and operation, resulting in stable and reliable performance.

2. Low cost: The manufacturing process is relatively simple, and the initial investment cost is lower than that of other types of switchgear (such as GIS).

3. Intuitive and convenient maintenance: The internal structure is clearly visible, allowing inspection and maintenance personnel to directly observe the status of key components, facilitating fault diagnosis and troubleshooting.

4. Environmentally friendly: The insulating medium is air, without the use of any greenhouse gases (such as SF₆), making it environmentally friendly.

Disadvantages:

1. Large Floor Space: This is its primary disadvantage. Because of the need to maintain air insulation distances, the switchgear is bulky and requires a significant amount of space in the distribution room.

2. Susceptibility to Environmental Impacts: The insulation strength within the switchgear is directly affected by environmental conditions. Humidity, condensation, dust, dirt, and chemical contaminants can all degrade the insulation performance of the air, potentially causing internal failures. Therefore, it places high demands on the distribution room environment (e.g., cleanliness and humidity).

3. Regular Maintenance Required: Conductive connections and switch contacts exposed to air can oxidize and accumulate dust, requiring regular cleaning, tightening, and inspection.