Earth Leakage Circuit Breaker

The ELCB is the short form of Earth Leakage Circuit Breaker, is a type of safety device which is used in the electrical installations with the high earth impedance in order to prevent shock. Earth leakage circuit breaker helps to prevent humans and animals from shock. The RCCB (Residual Current Circuit-breaker), is also known as ELCB (Earth Leakage Circuit-breaker). Two wires, one for phase and the other for neutral, are used to carry current in electrical appliances. Leakage current flows if the metallic part of the appliance comes in direct contact with the naked part of the phase wire that may be due to the insulation failure or accident. In the case, if the metallic part of the appliance comes in touch with an earthed object, the leakage current passes to the ground. Absence of proper earthing and shielding of this path may cause fire hazards and undesirable overloading. The earth leakage is the main cause of electric shock. So, this type of leakage and its after-effects may be avoided by using the RCCB, popularly known as ELCB. Its construction is more or less same as described earlier and is useful in protecting the following:

• Protection against fire.
• Protection against indirect contact.
• Protection against electrocution to human and domestic cattle.

Also protects from energy loss otherwise undetected leakage current causes continuous energy loss that may be in small amount but longer duration energy loss becomes considerable enough. Some of the main types of earth leakage circuit breaker are current operated earth leakage circuit breaker and voltage operated earth leakage circuit breaker. ELCBs were widely used in the TT earthing systems.  These days earth leakage circuit breaker has been replaced by RCDs or residual-current devices however several earth leakage circuit breaker are still in use.

Questionnaire:

• What is earth leakage circuit breaker? Explain.