What is a Miniature Circuit Breaker (MCB)?

MCB often referred to as “Miniature Circuit Breaker” is a kind of electromagnetic device used to protect the electrical circuit from unwanted breakdown. The device is operated automatically and hence switches off the low voltage circuit in overload or faulty condition.  In short, a Miniature Circuit Breaker can prevent your system from damages caused by a short circuit, over-current, or overload. During short circuit faults, it operates at less than 2.5 milliseconds, but in case of overload, the time increases from 2 seconds to 2 minutes.The device is safe to operate as it is completely enclosed in a molded insulating material. Mcb Manufacturers by our company since last 22 years.

Types of MCB

Before moving further, have a look at the types of MCB’s available in the market.

  • Type B MCB

Type B MCB is the best option for light commercial and residential installations

  • Type C MCB

These MCBs isused for high inductive commercial installation like small motors, fluorescent lighting and residential installation as well.

  • Type D MCB

Used for inductive loads which areextremely high such as UPS systems, X-ray machines, industrial welding equipment, etc.

The minimum trip current and maximum trip current of all types of MCB’s are provided in a tabular format.

Type of MCB

Min. Trip Current

Max. Trip Current

Type B

3 lr

5 lr

Type C

5 lr

10 lr

Type D

10 lr

20 lr


lr =rated current of the Miniature Circuit Breaker or MCB

A few words about the Trip Unit

The main part of the MCB is the “Trip Unit”which is responsible for the proper working of the device. Generally, the trip mechanism is differentiated into two types:

  • A bi-metal to prevent damage caused due tooverload current, and
  • An electromagnet to protect the circuit fromshort-circuit current

Advantages of MCB’s

There are several advantages due to which MCB is preferred over fuse. Here we go:

  • Automatically switches off the low voltage electrical circuit during the faulty condition
  • Quick restoration
  • The construction of Miniature Circuit Breaker Construction or MCB is robust and simple.
  • Controlled remotely
  • Safe and easy handling as compared to fuse
  • Can be used again and again i.e. minimal replacement
  • Low maintenance cost
  • Identification of the faulty zone is not a tedious task in MCB

Wrap Up:

So, if you want to install a device that protects alow voltage electric system from short-circuit or unwanted breakdown, go forMiniature Circuit Breaker Construction or MCB. Mccb Manufacturers by our company since last 22 years.

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