Why we use VCB circuit breakers in high transmission system not ACB?

We use vacuum circuit breakers (VCB) in high transmission systems because they have some advantages over air circuit breakers (ACB).

Some of these advantages are:- VCBs have a higher dielectric strength than ACBs, which means they can withstand higher voltages and currents without breaking down or arcing.

This makes them suitable for high voltage applications, such as transmission lines, substations, and power plants⁴.- VCBs have a longer service life and require less maintenance than ACBs, because they do not have any contacts or parts that wear out or corrode due to exposure to air or moisture.

They also do not need any refilling of gas or oil, unlike ACBs¹³.- VCBs are more compact and cost-effective than ACBs, because they have a simpler and smaller design that reduces the space and material requirements.

They also have lower operating costs, because they consume less energy and generate less heat and noise during operation⁴.- VCBs are more environmentally friendly than ACBs, because they do not emit any harmful gases or pollutants into the atmosphere during arc quenching.

They also do not pose any fire hazard, unlike ACBs that may cause sparks or flames when the contacts open or close¹.