What equipment is used to restrict short-circuit currents in power networks______________?
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Answer: D. reactors
Explanation
Reactors are specifically inserted into power networks to limit high short-circuit fault currents. These inductive coils add significant reactance to the circuit, restricting the maximum fault current to safe levels. By lowering potential fault magnitudes, reactors protect existing circuit breakers from exceeding their rated interrupting capacities. Current-limiting reactors are heavy-duty inductors connected in series with power system busbars or feeder circuits. As electrical grids expand and generation capacity increases, available short-circuit currents rise dramatically over time. Reactors introduce minimal voltage drop and power loss during normal operation while providing robust protection during faults.
Earth wires are installed overhead to shield transmission lines from direct lightning strikes rather than limiting short-circuit currents. Isolators are mechanical no-load switches used for safely disconnecting de-energized circuits for maintenance work. HRC fuses interrupt fault currents completely by melting, whereas reactors limit current magnitude without opening the circuit.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
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