ELCB and RCCB Difference, Advantages, Limitations, Diagram
ELCB and RCCB both are the electrical protective device but their working principle and function are different. In this article, we are going to discuss the difference between ELCB and RCCB with their advantages, limitations, and applications.
What is ELCB?
ELCB full form Earth Leakage Circuit Breaker. Its name implies that it is a circuit breaker that working with earth leakage current. Read what is earth leakage current with examples.
There are two types of ELCB, 1. Voltage Operated and
2. Current Operated
ELCB Limitations:
1. It is a voltage-operated device and cannot detect a very low leakage current.
2. It only trip the circuit or disconnect the power supply only when leakage current flowing through the earthing conductor.
3. It cannot give protection against electrical shock when anyone touches the live conductor accidentally.
4. Earthing connection need to break while connecting the ELCB as it connected in series with the earthing conductor.
What is RCCB?
RCCB means Residual Current Circuit Breaker. Actually, the current operated ELCB also called RCD(residual current device) or RCCB. It is a current operated device that works on the principle of sensing unbalance or leakage current.
RCCB Advantages:
1. RCCB can give protection against earth leakage from anywhere one or multiple sources in an electrical installation.
2. It does not require any earthing or grounding connection with it, only live and neutral connection enough for its operation.
3. It can give protection against electrical shock.
4. It more sensitive than ELCB and can detect a very low leakage current.
Constructional Difference between ELCB and RCCB
The construction of ELCB is very simple, it consists of a circuit breaker and a relay. The relay used in ELCB is a special type of latching relay. When the voltage applied across the relay it sends the signal to the circuit breaker to trip or disconnect the load from the main power supply.
On the other hand, RCCB has three major parts,
1. A Toroidal Transformer
2. Relay
3. Circuit Breaker
The toroidal transformer has one primary coil(which carrying line current flowing from source to load) and one secondary coil(which carrying return current flowing from load to source). It also has another coil called the sense coil. Sense coil is directly connected with a relay. When the relay got voltage from the sense coil it sends a signal to the circuit breaker to disconnect the power supply to the load.
Difference between the operation of ELCB and RCCB
The operation and working principle of ELCB is very simple. You can refer to the below diagram to understand it easily.
The relay is to be connected between the installation or equipment body and ground or earth. So when earth leakage occurs a voltage will arise across the relay. When voltage arises across the relay it will send the signal to the circuit breaker to disconnect the main power supply.
On the other hand, RCCB is to be connected in such a way that all power supply terminals and load terminals are going through the RCCB. Refer to the below diagram.
So when any imbalance occurs due to earth leakage a resultant flux is produced in the toroidal transformer which causes to induce emf or voltage in the sense coil. When the voltage produced in the sense coil it will turn on the relay. Once the relay got voltage from the sense coil, it will send the signal to the circuit breaker to disconnect the load from the main power supply.
Other important differences between RCCB and ELCB are given below.
ELCB VS RCCB or RCD
| ELCB | RCCB |
| Full-Form: Earth Leakage Circuit Breaker | Full-Form: Residual Current Circuit Breaker |
| Voltage Operated Device | Current Operated Device |
| Give protection against earth leakage from one particular source only | Give protection against earth leakage from anywhere one or multiple sources in an installation |
| Cannot give protection against electrical shock | Give protection against electrical shock |
| Low sensitive | Very high sensitive |
| There is no test button to check is it working properly | There is a test button available to check is it working properly |
| Comparatively low-cost device | High-cost device |
| Simple operation and working principle | Complex operation and working principle |
| Mostly used to protect devices and equipment | Used to protect all installation, circuits, devices, equipment |
ELCB and RCCB Difference, Advantages, Limitations, Diagram
Reviewed by Author
on
January 05, 2021
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Reviewed by Author
on
January 05, 2021
Rating: