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What is Miniature Circuit Breaker (MCB)?

Miniature Circuit Board (MCB) is a safety device with significant commercial and residential applications. It is an electro-mechanically driven automatic circuit protection device. It’s an automatic safety mechanism that prevents damage to electrical circuits due to excess current flow. It uses for low-voltage electrical networks like lighting and small electrical appliances.
It operates automatically, meaning if a short circuit or overcurrent occurs, the MCB will automatically trip, disrupting the power supply and preventing any damage. However, these are sensitive to minimal current variations and detect minute levels that exceed safety limits. MCB uses to interrupt a circuit during overload & short circuits.

It can be used as a substitute for fuses for domestic applications. The benefit of MCB over-fuses is that they are reusable even after interruption of the circuit after an overload or short circuit.

An MCB or miniature circuit breaker uses an electromagnetic device with a full enclosure encapsulated in molded insulation. Its primary function is to switch the circuit, i.e., to open the circuit (connected to it) automatically when the current passing through it (MCB) exceeds its setting. It can be manually switched ON and OFF, similar to a normal switch.

An MCB operates according to the magnitude of the overcurrent, which controls how long it operates. This means these get operated whenever overloads exist long enough to create a danger to the circuit being protected.

Therefore, MCBs don’t respond to transient loads such as switch surges and motor starting currents. Generally, these are designed to operate at less than 2.5 milliseconds during short circuit faults and 2 seconds to 2 minutes in case of overloads (depending on the current level).

A typical external appearance of an MCB shows in the figure. MCBs are manufactured in different pole versions, such as single, double, triple, and four-pole structures with other fault current levels.
Mostly, MCBs are linked to give two- and three-pole versions such that a fault in one line will break the complete circuit; hence, complete circuit isolation is provided. This feature will be helpful in the case of single-phasing in three-phase motor protection.

These are rated at 220V for DC supply and 240/415 for AC supply (single and three-phase) with different short-circuit current capacities. Typically, single-phase devices have a current load range of up to 100 A. Some MCBs have the facility to adjust their tripping current capacity, while some devices are fixed for some load current and short circuit rating.
MCBs perform many functions, such as local control switches, isolating switches against faults, and overload protection devices for installations or specific equipment or appliances.

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MCCB (Molded Case Circuit Breaker)

So, where does MCB find its uses?

These Miniature Circuit Boards are the most reliable solutions to ensure the safety of electrical equipment used in residential and many industries, including manufacturing, healthcare equipment, automotive electronics, consumer products, and agriculture. The primary reason for their effectiveness is their ability to perform in extreme operating environments and withstand higher temperatures, vibrations, humidity, and many other factors.

  • Residential Uses: Miniature Circuit breakers are an effective way to prevent damage due to power fluctuations in homes. They can be connected to electrical panels to safeguard home electrical systems from current overload.
  • Industrial Uses: MCB is vital for the efficient functioning and maintaining the safety of the electric equipment by optimizing the electrical flow.
  • Agricultural Uses: India is substantially an agriculture-driven economy with technology taking over traditional agricultural practices. Farmers are employing new-age equipment to increase power consumption and irrigation efficiency. MCB are an efficient mode of protecting and enhancing the performance of such agricultural equipment.

What makes BCH MCB a better choice?

BCH has been instrumental in devising reliable Miniature Circuit Breakers that meet every safety standard. Our high-performing MCB conforms to all industry standards for effectual output and multiple commercial applications. MCB are favored more due to the ease of use and relatively simple mechanism that makes MCB the most reliable and safe alternative to traditional fuses. BCH ensures that all industrial and safety standards are followed while manufacturing these MCB. Some of the essential benefits of BCH MCB are:

  1. Easy mounting: BCH MCB can easily be installed either by mounting on DIN rails or directly fitting into the panels. Due to their accessibility in various sizes and shapes, it is relatively simple to integrate them into installations or electrical systems.
  2. Ingress Protection: BCH MCB provide a higher level of safety. They have a good IP rating of IP 20, and thus are safe even to operate.
  3. Wide range of Current Rating: BCH MBCs are available in a varying range (SP, SPN, DP, TP, TPN & FP ) of current ratings ranging from as low as 0.5A to 63A.
  4. High Performance: BCH MCB can interrupt the current of up to 10KA without incurring any damage and effectively handle an Electrical arc. At the same time, they can withstand an impulse voltage of 4KV. It makes our MCB the most reliable choice for residential and industrial applications.
  5. Longer Life Span: BCH MCB provide several years of efficient performance. With every pole in the MCB secured individually, these MCB have a longer service life and ensure reliable performance throughout their life. The trip mechanism functions effectively for their entire life and provides safety against possible fire hazards if a fault occurs. Thus, increasing the lifespan of the equipment.
  6. Compact and efficient designs: BCH MCB has the most efficient design to accommodate two functions of current limiting and isolation in the same unit. Also, their compact design saves a lot of space.
  7. Interchangeable outlets: BCH MCB is designed in such a way as to enable users to interchange the line and load terminals. Thus, making them suitable for reverse-feed applications.
  8. Wide range Application: BCH MCB have a tripping curve of B & C type, thus making them suitable for both low and high current load applications where current surges are less like lighting, residential use, electronic equipment, and industrial applications where higher voltage current surges may be experienced.
  9. Adhering Industry Standards: BCH MCB are manufactured with adherence to standards IS/IEC 60898-1 for the range of 6A-63A and IS/IEC 60947-2 for the range of 0.5A-5A.

MCB is a circuit protection device that can protect a circuit or a piece of equipment from damage due to faulty conditions such as overloads and short circuits. The meaning of using it in the circuit is not to stop overload or short circuits from happening but to protect the circuits from more significant damages caused by them.

BCH Electric Limited is committed to delivering products that meet the higher industry standards in terms of safety, dependability, and performance, along with the assurance of higher service life and convenience of application. We promise the guarantee of secured electrical systems in all industries and households with our trusted MCB.

Specification and Features Miniature Circuit Breakers (MCB)

  • Rating: 0.5A to 63A
  • Poles: 1P/SPN/2P/3P/TPN/4P
  • Tripping Curve B &C
  • Conforms with standards
    • IS/IEC 60898-1 ( 6A-63A)
    • IS/IEC 60947-2 ( 0.5A-5A)
  • IP 20 Degree protection ( Finger Proofed terminals)
  • Breaking Capacity 10 KA
  • Impulse voltage withstand 4 KV
  • Suitable for isolation
  • Terminal Capacity 35 Sq mm ( Cu)
  • Possibility of bus bar termination at both ends.
  • Current Limiting design
  • Line Load interchangeability


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