Detailed Guide To MCCB

Safety is a vital factor for electrical devices. Electrical circuits with no safety mechanism are unsafe and dangerous for our use.

MCCB is a great tool for developing a safety mechanism for electrical circuits. MCCB acts like a resistive element to any excess current flow through a circuit. It acts as a fuse and protects the circuits from overloading. MCCB helps to develop safety mechanisms for electrical circuits. They protect the electrical circuits from any fire hazards.

MCCB is widely used in office buildings and residences. They are the most vital component of an electrical system that ensures safety against short-circuits.

Why do we need MCCBs?

Excessive current flow damages any electrical circuit. When an excessive current flows, it may lead to overloading or short-circuiting. Thus, a resistive element must help to control the surplus current flow.

MCCBs are resistive elements that stand for Moulded Case Circuit Breakers. They are electrical switches that operate automatically at the point of overloading. MCCBs break the electrical circuits when excessive current flows through them. Thus, circuits are protected from overloading and short-circuiting.

How do MCCBs work?

MCCBs work like a fuse. They help to stop the excess flow of current through a circuit. MCCBs use a bimetallic strip that is temperature-sensitive. As the current increases, the bimetal starts to heat up. The bimetallic strip responds to an excessive flow which triggers the MCCBs.

As the current exceeds the safety limit, the strip bends. A latch opens up to disconnect the circuit. Thus, MCCBs stop the overcurrent from flowing any further and save the circuit.

Basic components of MCCBs:

 All MCCBs have the following three parts.

1. Frame:

The frame forms an outer case of the circuit breaker. It is rigid and hard to provide shock-proof protection to the MCCBs. It is compact in design.

2. The operating mechanism:

It is a switch with three parts. They are on, off and trip. In case of an overcurrent, switch trips. It goes to the “off” state when the power turns off.

3. Trip Unit:

The trip unit is the principal part of an MCCB. This part has a bimetallic strip and an electromagnet. The trip unit of an MCCB reacts promptly to any overcurrent or short-circuit

Types of MCCBs:

Four distinct types of MCCBs vary based on the tripping current. They are as follows.

1. Type-B MCCBs:

They are highly sensitive circuit breakers. They are useful when the surge current is low. These help to trip off current that exceeds the safety limit by three to five times.

2. Type-C MCCBs:

They help to trip current that is ten times greater than the safety rating. Type-C MCCBs are perfect for a moderate surge in current.

3. Type-D MCCBs:

They come in handy when the current in the circuit exceeds the safety limit by twenty times. Type-D MCCBs are perfect for resisting a high surge in current.

4. Type-K MCCBs:

Type-K MCCBs are helpful when the current exceeds the safety limit by twice. They are sensitive to short-circuits. They provide complete protection against short-circuits and current overloads.

Shop from an extensive collection of different types of MCCB from Legrand.