Difference between MPCB and MCCB

Motor protection circuit breakers ad moulded case circuit breakers both are low voltage AC circuit protection devices. It is used to open and close the circuit manually and interrupt the circuit automatically on the occurrence of faults. MPCB and MCCB both are used to protect against overload and short circuits. Here any query regarding this topic please give a comment below as well as any opinion regarding this topic please inform me in the comments section.

Difference between MPCB and MCCB :

  • MPCB stands for motor protection circuit breaker while in MCCB stands for molded case circuit breaker. 
  • MPCB is used to manually turn on and off electric motors and at the same time protect them from different types of faults occurring in motors while in MCCB are used in power distribution and low voltage distribution circuits as well as motors loads.
  • MPCB is specially designed for motor protection while in MCCB are specially designed for general-purpose circuit protection.
  • MPCB can protect the motor against overload, short circuit, phase loss, and under-voltage faults while in MCCB can protect the motor against overload and short circuits. This circuit can also provide under-voltage, earth faults, and phase failure faults but these features are made available with additional accessories.
  • MPCB can withstand the stating currents without interrupting the circuit while in MCCB is used as backup protection for a motor, it may interrupt the circuit if it is selected based on its full load current.
  • MPCB is maximum load current can be set based on the full load current of the motor while in MCCB is overload, short circuit and trip relay delay time can be set based on the applications.
  • MPCB is selected based on the full load current of motors and maximum possible short circuit current while in MCCB are selected based on the maximum current and maximum short circuit current interrupt safety. 
  • MPCB has an adjustable bimetallic strip for overload protection. this strip can be adjusted between two set values but the MCCB overload value of MCCB can be  40% to 100% of its rated value.
  • MPCB can protect a motor against overload and short circuit while in MCCB when used in motor protection circuit can protect against short circuit only. Hence additional overload relay and contactor.
  • A motor can be directly ON and OFF manually using an MPCB, the contactor is optional while in  MCCB contactor is a must in these cases.
  • Some MPCB comes with auto-resetting features that allow motors to resume its operation after a short period from the occurrence of overload trip while in MCCB is feature is not available.
  • Overload relay is not required for motor circuits with MPCB backup but in MCCB overload relay is required.
  • Some MPCB comes with an auto-resetting feature that allows motors to resume its operation after a short period from the occurrence of an overload trip while in MCCB feature is not available.

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