Switchgears are used in power systems to protect against any short circuits, spikes, and overload of current. The term is commonly used to refer to various electrical disconnection equipment in a circuit such as fuses or circuit breakers that help isolate the electrical equipment.
The role of switchgear in power systems can be understood by looking at its functions, which are:
Electrical Protection: The switchgear in power systems allows more than one electrical current source to flow through a load. It protects people, animals, and the other nearby electrical equipment. The switchgear detects over-current and overloads through thermal energy. It detects the emission of thermal radiation from the rising temperature levels and cuts off the power before the situation becomes dangerous.
Electrical Isolation: Switchgears isolate the energized areas of the circuit. Two interconnected components are separated from each other by creating a gap or an actual barrier. It offers the necessary protection to the persons who are in contact with the power system or equipment for maintenance or repairs.
Control: Switchgears measure and control the electrical load in the system. The different types of control functions are emergency switching, emergency stopping, and functional switching. The switchgear can energize or de-energize any element of the system or just one piece of equipment. It can de-energize a circuit if there is a potential threat of circuit overheating before it can cause an electrical shock or a fire. It can also de-energize the equipment for protection.
The type of the switchgears may vary according to the needs, location and level of protection required. Each type of switchgear power system has its unique characteristics to meet the specific needs. Among all the different types available, GIS (Gas Insulated Switchgear) systems are usually considered the most effective. In this system, the conductors and contacts are insulated by pressurized Sulfur Hexafluoride gas (SF6), which offers sufficed protection to the contacts. And although it is costlier than other alternatives, its effectiveness, and protection level more than make up for the higher price. These gas breakers are recommended by experts for heavy-duty industrial and commercial applications.