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Which of the following can be placed near the main board to protect the whole installation?

Which of the following can be placed near the main board to protect the whole installation? Correct Answer ELCB

  • ELCB stands for Earth Leakage Circuit Breaker.
  • It is a safety device used in electrical installations with high earth impedance to prevent shock.
  • It is used to directly detect currents leaking to earth from an installation and cut the power.
  • An ELCB must be always connected in the circuit at the entry of supply to load after energy meter.
  • It detects small stray voltages on the metal enclosures of electrical equipment and interrupts the circuit if a dangerous voltage is detected.
  • ELCBs are specially used to disconnect the supply underground fault condition.
  • Earth Leakage Circuit Breaker (ELCB) works on the principle of residual current.
  • Current operated ELCBs are safer as they operate on the principle of the vector sum of the line currents and neutral current.
  • It is used to provide protection against accidents by rapidly interrupting dangerous contact voltage which may present in the faulty electrical equipment.

Note:

  • The sensation of electric shock is caused by the flow of electric current through the human body to the earth
  • When a person comes in contact with electrically live objects like water heaters, washing machines electric iron, etc., the extent of damages caused by this current depends on its magnitude and duration
  • This kind of current is called the leakage current which comes in milli-amps
  • These leakage currents being very small in magnitude, hence undetected by the fuses/MCBs are the major cause for the fires due to electricity
  • Residual current operated circuit breakers provide maximum protection from electric shocks and fires caused due to earth leakage current and also prevents the waste of electrical energy
  • These residual current circuit breakers (RCCB) are popularly called as earth leakage circuit breakers (ELCB)

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