Earth Leakage Circuit Breakers: The Working Principle

Earth Leakage Circuit Breakers (ELCBs) work by detecting earth or ground faults that are typically caused by a current imbalance in the circuit.

When your ELCBs recognize ground faults, they automatically trip or shut off the power supply to prevent hazards, such as fires and electrical shocks.

In this blog, you will learn about the working principle of ELCBs including the following:

• What causes ground faults.
• The dangers of electrical shocks.

How do earth leakage circuit breakers work?

Earth leakage circuit breakers work by shutting off or tripping the electrical current flow when the device senses earth faults or a voltage imbalance in the circuit.

This circuit breaker helps prevent people and properties from electrical fires and shocks.

The Simple Working Principle of ELCBs

Earth leakage circuit breakers help prevent electrical accidents by interrupting the power supply to the circuit.

Here’s a simple step-by-step overview of the working principle of ELCBs:

Phase 1: Monitoring the current flow

The winding transformers of earth leakage circuit breakers monitor the flow of current in the circuit.

If the current is zero or known as the balanced state, the ELCB is not activated.

Phase 2: When earth faults are detected

Should there be ground faults, the sensing wires or coils in the circuit detect the current imbalance in real time.

Phase 3: The ELCB analyzes the current flow

When the sensing coils detect current imbalance, the ELCB now analyzes and calculates the difference in the live and neutral conductors.

Phase 4: The ELCB shuts off the power supply

For voltage ELCBs (VO-ELCBs), the circuit breaker shuts off immediately when the voltage reaches above 50 volts.

For current ELCBs (CO-ELCBs), the device trips or shuts off quickly when a ground fault occurs.

An ELCB then interrupts the power supply to prevent electric shocks and fires.

What Causes Earth or Ground Faults

Firstly, an earth fault refers to a phenomenon where live conductors or power cables get damaged and come in direct contact with the earth’s surface.

There are various reasons that cause earth or ground faults.

1. Insulation Failure: This occurs when the insulator on the wires is worn out due to irregular maintenance or rodent bites.

2. Line Overload: Overloaded power lines can break overhead transmissions, which results in ground fault.

3. Water or Moisture Exposure: As a conductor of electricity, water poses a great danger to electrical boxes. 

4. Incorrect Wiring: Miswirings and loose connections can cause the electrical flow to come in contact with other pathways or to the ground.

5. Dirt: Dirt or debris in the electrical box can also cause earth faults that lead to fires.

The Dangers of Earth or Ground Fault

In the absence of ELCBs, earth or ground faults can cause hazards.

Electrical shock, being the most common effect of ground fault, can cause serious injuries, such as:

• Breathing problems.
• Cardiac arrest.
• Spasm.
• Skin burns.
• Seizures.
• Loss of consciousness.
• Loss of hearing or vision.
• Severe headache.

Key Takeaway

Earth Leakage Circuit Breakers (ELCBs) are a great prevention of electrical hazards caused by earth faults.

Without ELCBs, electrical fires and shocks can occur in humans, which can lead to serious injuries.

When choosing ELCBs for your commercial or industrial space, it’s crucial to consider manufacturer reputation and safety compliance.

This will help you ensure optimal safety and peace of mind.