MCB – Miniature Circuit Breaker and RCBO – Residual Current Circuit Breaker with Overload Protection are circuit protection devices. These devices are commonly used in low-voltage power distribution and can be seen in distribution boards in homes, offices, commercial buildings, etc.
Difference between MCB and RCBO
|MCB – Miniature Circuit Breaker||RCBO -Residual Current Circuit Breaker with Overload Protection|
|MCBs can provide protection against overcurrent and short circuits only.||RCBOs can provide protection against overcurrent, short circuit, and earth leakage currents.|
|MCBs are selected based on the load, the maximum short-circuit current it can interrupt safely, and trip curve.||RCBOs are a combination of MCB and RCCB. It is selected based on the load and maximum short-circuit current it can interrupt, trip curve, and maximum leakage current.|
|MCBs monitors the current flow through the line and interrupts the circuits during overload and short circuit.||RCBOs not only monitor the current flow through the line but also the return flow in the neutral line. It can interrupt the circuit during overcurrent, short circuit, and earth leakage.|
|Cannot protect against earth faults.||RCBOs can protect against earth faults and electric shocks that MCBs may not do.|
|MCBs are used to protect lighting circuits, air conditioners, and other home appliances(Other than heaters and devices which have direct contact with water).||RCBOs are used for protection against electric shocks. Hence it is mainly used to interrupt the power to water heaters, power sockets, etc. where there is a possibility of occurrence of electric shock.|
For a better understanding watch the video:
MCB and RCBO connection
To detect ground faults, RCBO required a connection to ground. Therefore unlike MCBs, RCBOs has additional terminals/leads for connections to the neutral and the ground.
Here is a sample RCBO datasheet.
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1. What is the difference between MCB and RCBO?
2. The difference between RCBO and MCB.
3. Where to use RCBO and where to use MCB?
5 thoughts on “Difference between MCB and RCBO”
What are the existing RCBO poles in market? ( 1P, 2P…. etc)
1P, 1P+N rcbo are available.
How would an 1P RCBO work? It can’t measure return current without N.
To detect ground faults, RCBO required a connection to ground. Therefore unlike MCBs, RCBOs has additional terminals/leads for connections to the neutral and the ground. Kindly check the attached RCBO datasheet for more details