USAGE OF RECLOSERS OVER POWER DISTRIBUTION SYSTEM


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              USAGE OF RECLOSERS OVER POWER DISTRIBUTION SYSTEM

Reclosers are actually circuit breakers and its prime goal is to provide electric power continuously without any distribution problems it senses and interrupt fault current and automatically restores service automatic circuit recloser is a self-contained device it has the intelligence to sense overcurrent to time and thus it will interrupt the fault current if any permanent fault occurs the recloser locks and then it will open after a preset number of operations and that’s how recloser isolates the faulted portion from the main part of the system

Autorecloser = circuit breaker + automatic closing mechanism

Classification of reclosers

Automatic circuit recloser classification

  • Single phase or three phase
  • Control- Hydraulic or Electronic
  • Interrupters: oil or vacuum
  • Insulation: oil, air or epoxy

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Single phase electronically controlled recloser

WORKING

Reclosers are used in power distribution systems from substations to residential utility poles it ranges from small units which are used in single phase distribution lines to three-phase reclosers used in substations and on high voltage power lines up to 38 KV

80 percent of the occurs are temporary faults which can be removed by reclosers

some of the temporary faults are occurred by

  • Conductors touching one another due to the heavy windblown
  • Flashing over an insulator by lightning surges
  • Energized line is touched by tree branches
  • Switching surges that flash over an insulator
  • Reptiles or birds come between energized line

If there is any permanent fault occurs the recloser will check it three times and then it turns off and then the line fault must be repaired manually and reset the recloser to reclose the power

Permanent faults are occurred by

  • Damaging of power lines or other equipment by lightning strikes
  • Breaking of the wire by fallen tree limbs
  • Knocking down of the poles by a vehicle collision

TYPES OF AUTO RECLOSERS

SINGLE POLE

  • It will operate only in the faulted phase
  • Selecting relays are required to choose the phase
  • Complex and expensive
  • Longer arc times will be caused by capacitive coupling
  • There will be individual closing and tripping mechanisms for each phase

THREE POLE

  • Regardless of the fault type three phases are operated

  • Requires sync check

  • When all three phases open generators tend to drift apart

APPLICATIONS OF RECLOSER

  • It can act as a primary feeder protective device in a substation
  • Protects the main feeder from outages due to the faults on the taps
  • It will sectionalize long feeders and thus it prevents outages of the entire feeder when a permanent fault occurs