"Earth fault loop impedance" is a measure of the impedance, or electrical resistance, on the earth fault loop of an AC electrical circuit, explains Alert Electrical. The earth fault loop is a built-in safety measure within electrical systems to prevent electric shock.Know More
Coming into contact with a live current in an AC circuit could potentially be fatal. This can occur by accident when a non-live portion of an electrical system becomes live due to a system fault or short. An upstream protective device, such as a residual current device, must quickly detect such a short has occurred and intervene by shunting the current through the earth fault loop rather than the individual in contact with the live current.
Alert Electrical further explains that the greater the impedance value on the earth fault loop, the longer it takes the RCD to make the current path switch. If the earth fault loop impedance value is too great, this delays the switch to the point a person may still receive a harmful, even fatal electrical shock before the switch can take place. For that reason, the earth fault loop impedance of every AC circuit must be low enough for the RCD to function properly.Learn more about Electricity
The current divider rule states that the portion of the total current in the circuit that flows through a branch in the circuit is proportional to the ratio of the resistance of the branch to the total resistance. This rule allows for a shortcut in determining the branch current in a parallel circuit, which is simply to multiply the ratio of the resistances by the total current.Full Answer >
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When a short circuit occurs, electrical current experiences little to no resistance because its path has been diverted from its normal direction of flow. This in turn produces excess heat and can damage or destroy an electrical appliance. It can also create a fire hazard and an electrical shock hazard if left unattendedFull Answer >
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