MCBs and MCCBs have commonly used circuit protection devices. These devices provide protection against overcurrent and short circuits. There are a few difference between MCB and MCCB.
Overview of MCB:
- These are thermal / thermo-magnetic devices
- Provides protection against overcurrents and short circuits.
- Available up to 100A and have a maximum short circuit capacity of 25kA.
- Commonly used in lighting circuits.
- The trip level cannot be varied.
- Available in single, two, three and four-pole versions.
Overview of MCCB:
- Maybe Thermal/ Thermo-Magnetic/ Electronic trip type
- Primarily provide protection against over-current and short circuit.
- Can provide protection against Earth Fault, Residual Currents, Under voltage etc
- Available up to the rating of 2500A.
- The trip level can be varied in adjustable trip type MCCBs.
- Remote ON/OFF is possible with additional accessories
- Commonly used is loads over 100A and motor protection circuits.
- Some MCCBs are microcontroller based.
- Available in single, two, three and four-pole versions.
Major difference between MCB and MCCB
- MCBs are operates based on the thermal property of current whereas MCCB is a microprocessor-based device which uses current sensors to measure the magnitude of current and isolate a circuit.
- Maximum normal current rating of an MCB is 125A whereas that of an MCCB is 1600A.
- The maximum short circuit capacity of an MCB is 15kA whereas the maximum short circuit rating of an MCCB is 85kA
- The trip characteristics of an MCB is fixed and preset. But characteristics of an MCCB can be varied based on application.
- MCBs are designed to protect residential loads and small electronic loads whereas MCCBs are capable of handling much heavier industrial loads.
