Electrical Engineering XYZ MCQs
Earthing switch is used for:
- Protection of equipment from ground faults
- Measuring of safety voltage
- Discharging residual energies
- Any of these
Correct answer: 3. Discharging residual energies
Explanation: An earthing switch is a device used in electrical systems to safely discharge residual energies from equipment. When electrical equipment is shut down or isolated from the power source, there may still be residual electrical energy stored within the system. This residual energy needs to be safely discharged to prevent potential hazards to personnel and to protect the equipment from damage.
Earthing switches are often used in conjunction with disconnect switches or circuit breakers. They provide a means to connect the equipment to a low impedance path to ground, allowing any remaining electrical energy to dissipate harmlessly. This helps in ensuring that the equipment is safe to work on and minimizes the risk of electrical shock or damage during maintenance or repair activities.
While protection of equipment from ground faults is an important aspect of electrical safety, earthing switches are not primarily used for this purpose. Measuring safety voltage is typically done using specific measurement tools and techniques rather than through an earthing switch. Therefore, the correct answer is discharging residual energies.