Everything You Need to Know About Earth Leakage Circuit Breakers (ELCBs)

Earth Leakage Circuit Breakers (ELCBs) are electrical devices designed for your safety and protection from potential electric shocks.

This electrical device detects small stray voltages on the metal casings of your electrical equipment.

If the ELCB recognizes a dangerous voltage level, it immediately interrupts the circuit.

To learn more about ELCBs, continue reading below.

What is the purpose of an ELCB?

The primary purpose of an ELCB is to protect humans and animals from instances of electrical shocks.

Apart from preventing earth leakages, ELCBs also function as the following:

• Prevent electrical fires caused by short circuits.
• Ensure electrical safety during installations.

How to Properly Install An Earth Leakage Circuit Breaker (ELCB)

Installing an ELCB is easy, but needs professional guidance for accuracy and safety.

For reference purposes, here’s a short guide on the process of installing ELCBs:

Step 1. Turn the Power Supply Off

Before you begin, make sure to turn off the main power supply for optimal safety during installation.

Step 2. Choose the Location

Location is important when installing ELCBs. 

Make sure to choose the most appropriate location so that your ELCB can be easily accessible.

Also, choose a location where there is proper ventilation around the device.

Step 3. Position the ELCB Properly

Mount your ELCB properly and securely on a sturdy surface using screws or mounting brackets.

These tools are usually provided in the package along with the ELCB.

Position your ELCBs vertically for effective heat dissipation or energy transfer.

Step 4. Secure Wire Connections

Connect the wires to their corresponding ELCB terminals.

The incoming wire from the power source is typically connected to the line terminal.

Meanwhile, the outgoing wire (load) must be connected to the load terminal.

Moreover, connect the grounding wire to the grounding terminal on the ELCB.

Proper grounding is crucial for the device to detect earth faults.

Be sure to follow the manufacturer’s instruction manual for guidance.

Step 5. Perform a Test

After all wire connections are done, perform a test to see if the device works.

To determine if the ELCB is working, it must trip and cut off power to the circuit.

Step 6. Run a Final Test

You need to run performance tests at least twice.

This is to ensure that your ELCB is working as intended and the wires are securely connected.

After that, make sure that you secure a cover for the electrical panel or distribution board.

Step 7. Perform Regular Maintenance

Just like any device, be sure to perform regular maintenance checks.

It’s important to check for:

• Signs of damage.
• Wear and tear of the wirings.

Be sure to seek professional advice and inspection for the optimal safety and performance of your ELCBs.

2 Main Types of Earth Leakage Circuit Breakers (ELCBs)

ELCBs have various types. Each comes with different functions and usage.

Here are some of the most common types of ELCBs:

Voltage-Operated (VO-ELCB)

VO-ELCBs function depending on the voltage between the live and neutral conductors.

They work with the aid of relay coils:

• One end (of the coil) is connected to a metal body.
• The other end is connected to the ground.

How do VO-ELCBs work?

Let’s say, the voltage of a certain equipment rises.

This will lead to a difference in the voltage between the said equipment and the earth.

What happens next: The electric current will pass through from the load metal framework to the earth.

This can be prevented when a voltage ELCB is installed.

If the VO-ELCB detects above 50 volts, it will shut off automatically.

As a result, voltage ELCBs will eliminate earth leakages and electrical shocks.

Advantages of Voltage ELCBs

1. VO-ELCBs are less sensitive than other types, which means less false-tripping or shutting off of the power supply.
2. This circuit breaker is less expensive than current ELCBs.

Current-Operated (CO-ELCB)

The working principle of CO-ELCBs revolves around 3 winding transformers:

• 2 primary windings.
• 1 secondary winding.

These windings are respectively made of:

• Phase.
• Neutral.
• Wire-wound coils.

These windings are called “Core Balance Current Transformers (CBCT)” collectively.

What is the most common instance when current ELCBs are needed?

Firstly, ELCBs are not activated when the current is zero known as the balanced state.

But when an electric fault occurs, it creates an unbalanced magnetic field as it flows to the ground.

The phase and neutral windings of CO-ELCBs detect this imbalance and now send signals to the secondary windings that connect to the sensing circuit.

Current ELCBs then detect the fault and shuts off the current to prevent shocks or damages.

Advantages of Current ELCBs

1. CO-ELCBs are considered the most reliable devices when it comes to preventing electrical shocks.
2. This device trips or shuts off the power supply entirely when it detects faults surrounding the circuit.
3. Current ELCBs do not need an earth connection.

Pros and Cons of ELCBs

Advantages	Disadvantages
ELCBs help prevent electrical shocks by detecting earth faults or voltage differences.	ELCBs can be subject to false-tripping due to external factors, such as temperature, moisture, fluctuations, or electromagnetic interference.
This device helps prevent short circuits, electrical fires, and other further damage, especially at home.	This electrical safety device may not be compatible with certain equipment, especially those requiring high capacitive loads.
ELCBs can be installed in various electrical settings, such as single or three-phase circuits.	ELCBs can be quite expensive compared to standard or regular circuit breakers.
This electrical device is designed with international safety standards and compliance.	Aside from the cost, ELCBs also require ongoing maintenance which can incur additional expenses.
ELCBs have 2 main types that sense earth faults and voltage imbalance.	Ignoring regular maintenance checks for your ELCBs can lead to danger.

Key Takeaway

Earth Leakage Circuit Breakers or ELCBs provide the utmost safety for you and your space by preventing earth faults from your equipment.

With the right installation process and ELCB quality, you can be assured that your residential, commercial, or industrial space is safe from potential electrical shocks and damages.

Moreover, choosing the right ELCB manufacturer matters in the overall quality of your circuit breakers.