Air-insulated technology has been dominating the switchgear industry for the past decade and for good reasons. Switchgears are an essential component of modern-day electronic equipment. They facilitate power distribution systems making power generation a reliable and safe process.

Companies that invest in high-quality switchgear expect them to function for at least two decades. The reason why there’s so much talk about using air insulated switchgear (AIS) is that they offer longevity, high-performance functionality and other advantages over other types of switchgear. The main opponent of AIS is gas-insulated switchgear (GIS). Let’s compare the qualities and circuit components of these two switch gears to find out which is better.

What Separates AIS from GIS?

In AIS, air acts as the primary insulating medium. This metal-enclosed switchgear comes with extensive shutters. The primary bussing of these switchgear is layered with insulation materials. To intercept faults in the electric arrangement, AIS uses the classic ‘draw out vacuum’ mechanism.

On the other hand, GIS’s impenetrable insertions are full of insulating gas. The most commonly used insulating gas in GISs is sulfur hexafluoride.

Companies should choose either of the two based on their requirements and the preferences of the operators. For instance, AISs are perfect for a 33 kV Panel Switchboard. The interruption ratings for AIS range from 4000A to 63kA. GISs only offer interruption ratings of 3000A to 40kA.

AIS is More Flexible and Expansion-Friendly

AIS is far more flexible than GIS when it comes to operationality. In case the electric system’s application has to be altered, making modifications to AIS is far easier. It is also easier to expand electric arrangements while using AIS equipment. Making such primary circuit modifications is impossible when using GIS. Hence, operators who often engage in primary circuit modifications or expansions must select metal-clad AIS over GIS.

Easier to Maintain

AIS equipment is very easy to install. Operators have no trouble testing or maintaining these products as long as they don’t let environmental contaminants harm the product. Hence, it makes sense to install AIS in job sites where there’s no humidity and minimal environmental pollution.

Flexible Costs

Electric arrangements where voltage decreases over time need to have AIS. The cost of AIS is much less at lower voltages.

The lower the voltage requirements, the cheaper the AIS equipment. On the other hand, GIS equipment costs the same irrespective of the voltage ratings or requirements.  

Even for equipment that have 5 kV voltage ratings, operators will have to pay top-fee to get GIS equipment. At such low voltages, the cost of AIS can be three times less than GIS equipment.

Making a Choice

When considering which switchgear to get, AIS or GIS, electric operators must consider these factors -

• The equipment’s ratings
• Whether the switchgear can meet actual application requirements
• The initial cost of the switchgear
• Maintenance costs of the equipment
• Environmental influences at the job site
• Future expansion plans

The qualities that AISs offer make them the preferred choice for all operators who have previously installed or maintained air-insulated switchgears.