Difference between MCB and MCCB

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:

difference between mcb and mccb
  • 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:

difference between mcb and 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.

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