5 October 2019

Advantages and disadvantages of ELCB

ELCB stands for Earth leakage circuit breaker, It is one kind of safety device used for installing an electrical device with the high earth impedance to avoid shock. The main advantage of the Earth leakage circuit breaker is to stop damage to humans and animals due to the electric shock. Let us have to deep inside the information about the merits and demerits of Earth leakage circuit breaker to better understand this topic.

Advantages of ELCB:

  • This device is not sensitive to faults.
  • It is cheap and efficient.
  • It protects animals and humans from electrical shock.
  • In this process, when the installation has two connections to the earth, a nearby high current lightning strike will cause a voltage gradient in the soil, presenting the ELCB sense coil with enough voltage to cause it to trip.

Disadvantages of ELCB:

  • Failure to respond at certain conditions.
  • ELCB needs a sound earth connection, for load protection.
  • Nuisance trips.
  • Electrical leaky appliances water heater, washing, machine, and coolers may cause CKL to trip.
  • They may be tripped by the external voltage from something connected to the earthing system such as a metal pipe.
  • They do not detect a fault that doesn't pass current through CPC to earth rod.
  • They do not allow a single building system to easily split into multiple sections with independent fault protection because the earthing system is bonded to the pipework.
  • If the electrical installation earth rod is placed close to another earth of a building, then a high earth leakage current from other buildings can raise the local ground potential and cause a voltage difference across the two earth, again tripping the ELCB.
  • ELCBs introduce additional resistance and an additional point of failure into enough voltage to cause it to trip.
  • They may be tripped by external voltage from something connected to the earthing system such as metal pipes, TN-S earth or a TN-C-S combined neutral and earth. 
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