What is an MCB and How Does it Work?

-An MCB (Miniature Circuit Breaker) is an electromechanical device that is designed to protect your electric circuits from over current. This can happen either by an electricity overload or a short circuit. Before MCBs, fuse wires were used to protect against over-currents.

The principle of this was that the fuse wire would simply melt when the electric current overflowed. This would break the connection between the switch and the wire, hence protecting your home’s electric circuits.

What is an MCB

Fortunately, nowadays, electrical faults tend to occur at a far slower pace than before. The way we protect against over-current is by using a circuit breaker. In essence, the circuit breaker acts as a relay to turn off the power to the power source if an electrical fault takes place.

A circuit breaker will have several segments. Each segment will protect the supply to a part of the house and if a fault occurs within that part of the house, then the fault is detecting and the circuit breaker will automatically shut off the power to that part of the house. We now cover the circuits contained within a circuit breaker.

How does an MCB work?

The Clipsal MCB is much like the fuse wire in this regard, except instead of using copper, we use a piece of tantalum and an insulator made of insulating material (MOSFET). It also requires a grounded metal resistor to make up a short circuit.

This has to be installed by the electricity supply company as the MCB only protects against low voltage faults. In contrast, the fuse wire is design for AC, Low Voltage faults. The resistor and insulator are simply attached to the electrical input, which can be a ground plane or a low voltage switch.

The power supply has to supply at least 1.2A to the MCB, although this varies with the specification of the Clipsal MCB. If there is no supplies, the MCB will not work as it will overheat.

How do different voltages affect the power of an MCB

The first unit produced was the 60-ohm cathode reference circuit breaker, which went into production in 1940. It was sold in both 50- and 60-volt versions and operates at either a small or large pulse. Its application was mainly in the marine, oil & gas, telecommunications, and power industries.

The initial idea was that, because it operates at a very high frequency (200 kHz) (and thus a very high voltage), the unit would be a total “shield” from any risk of failure – unlike with an ordinary circuit breaker which runs at a high frequency (1500 or 3000 hertz) and therefore at a lower voltage.

The original 60-volt versions were too large to use in the marine industry. So they were often fitted as an add-on or replacement for the existing 50-volt models.

What are the advantages of using an MCB

Today the technology that we use, especially in the case of older equipment, is a lot more sophisticated. The most obvious advantage of a Clipsal MCB is the fact that it works far more effectively and without the risks associated with fuse wire. Why would we use MCBs?

They are expensive but the solution is cheaper than having to replace equipment. When you consider that replacement is not free, the cost is clearly a huge consideration! They are generally very robust and should last for years to come – usually several decades!

An MCB is simply a switch that will switch off the circuit when the expected over-current voltage reaches a certain level. So, for example, a miniature circuit breaker that normally uses 12 volts can be adapt to allow the protection voltage to reach 50 volts.

Conclusion

Manufacturing electronic products is a relatively cheap way to produce large numbers of commodity products. That said, this doesn’t mean that all aspects of electronic products manufacturing should be throw away as landfills: metal and other metals can recycle into new metal products. Most plastics will recycle into new materials, perhaps of the same type or similar.

Flexible circuit boards can recycle into something else – maybe packaging for example. Even when the plastic PVC filament is degrading, it can be re-use as a substrate for making more PVC filament or in any number of ways. Even when circuit boards incinerate, the wires within are reusable.