Electrical Engineering XYZ MCQs
Isolator in sub station can only be opened under which of following condition:
- Short circuit
- Full load
- No load
- Any of the above
Correct answer: 3. No load
Explanation: An isolator in a substation is a switch that is used to disconnect a part of the electrical circuit for maintenance or repair purposes. It is crucial to ensure the safety of personnel and equipment during such activities. Opening an isolator under load conditions, especially during short circuit or full load, can lead to arcing, sparking, and potential damage to the equipment.
The preferred condition for opening an isolator is “No load” because it minimizes the risk of electrical arcing and ensures a safer operation. When the circuit is not carrying any load, there is a lower chance of creating sparks or damaging the isolator contacts during the opening process.
Therefore, the correct condition for opening an isolator in a substation is when the circuit is under “No load.”