MCCB Full Form

MCCB Full Form is a Moulded Case Circuit Breaker. It is used in various electrical appliances to prevent misuse and short circuits. The usage of MCCB is widely extended and it is safer than fuse.  To regulate the electric flow and maintain the current, MCCB is used. However, it should be installed carefully to avoid any consequence.

What is the Full Form of MCCB?

MCCB full form is Moulded Case Circuit Breaker. In the motor feeders, MCCB is used in the range between 250 amps to 800 amps. This system of circuit breaker basically protects the entire electrical system from various complications such as overloading and overshading and resist the conditions of short circuit issues. Generally, MCCBs are the electrical current flow protection and regulation gadgets that are used mostly with a wide range of voltages (both low and high). MCCBs are commonly known to have adjustable trip settings and can retain as much as 2500 amps in current ratings. A miniature circuit breaker known as MCCB is the gadget that automatically switches off the entire electrical circuit when there is abnormal condition of the electricity flow in the system which can mean in overload conditions as well as faulty conditions.  It is extensively used in low voltage electrical networks instead of the fuse usage as the handling and usage of an MCB is electrically safer than the usage of fuses.

MCCB is popularly in use to prevent and restrict electrical short circuits. Various types of MCCBs can be applied for various fields such as domestic, industrial and commercial purposes. In addition, it also can be used to fulfill other current maintenance requirements by installing new features such as UV trip, remote closing, sensor etc.

Working Principle of MCCB

The MCCB system uses a special device such as a ‘temperature-sensitive device’ which is known as the thermal element as well as the current sensitive electromagnetic device which is also known as the magnetic element in the magnetic field. This special device is used in order to provide and improve the overall trip mechanism which is based on protection and isolation purposes. The MCCB device is used to provide overload protection and also the electrical fault protection from any type of short circuit situations and the device also consists of an electrical switch for immediate disconnection during the voltage fluctuation.

In the MCCB system, the temperature-sensitive components are present inside. These components are essentially a bimetallic contact that helps in the electricity regulation. This bimetallic contact basically consists of two metals that when exposed to the higher levels of temperature expand at different rates. During the normal conditions of its function, the bimetallic contact will allow the electric current to pass through the MCCB system in its undisturbed stage. When the total value of the flowing current exceeds the amount of trip, then the bimetallic contact will start to heat up and bend away due to different limits of thermal rate of heat expansion towards the chemical construction. Eventually, the consequence of heating will be such that the contact will end up to such a point that it is physically pushing the trip bar and will also unlatch the contacts causing the circuit to be interrupted and hindered by providing protection towards the entire electrical system from any type of unwanted situations or shocks.

As per the electrical fault protection system, built against the short circuit currents, it is based on the principle of electromagnetism, the MCCB provides a quick and instant response to any short circuit fault. Thereafter, when a short circuit fault or any damage has occurred inside the entire electric circuit, a large current begins to flow through the solenoid and as a consequence, a strong electromagnetic field is established. The electromagnetic field basically attracts the trip bar and opens the contacts in the process.

Moreover, in addition to all the tripping mechanisms, MCCB can also be used as a device such as a manual disconnection switch. This switch can be used in such a case of emergency or even any type of maintenance operation. The main preventive mechanism is creating an arc within the range when the contact opens from each other to prevent any current flow outside the wire.

Advantages of MCCB 

Apart from the properties and use, there are various advantages of Moulded Case Circuit Breaker known as MCCB. For example, MCCB consists of an ‘adjustable trip’ that can be used for both low and high currents. MCCB can interrupt heavy flow of currents internally and can handle large amounts of current flowing through them. MCCB also consists of a little rip as it switches quickly whenever faulting time or sudden short circuit occurs. And, the movable trip of MCCB can instantly interrupt large power flows through preventing or regulating the current. In addition, MCCB offers provision of remote switches where it has on/off features, which can be used manually. Moreover, the compact and small size of MCCB is much easier and convenient to handle and is much more advanced than MCB. 

Disadvantages of MCCB 

Alongwith the advantages, there are a few disadvantages of Moulded Case Circuit Breaker known as MCCB. With regard to this, MCCB has limited the use and application in domestic, special zone and small-scale industrial purposes. Also, Molded Case Circuit Breakers cannot be used and are prohibited in high voltage industrial areas. 

Applications of MCCB

Different applications of MCCB are mentioned below:

• MCCB has both high current voltage capacity as well as adjustable trip establishing capacity. In this aspect, it can be used for both low current as well as high current settings and adjustability.
• MCCB is also used for a welding machine, as this machine creates a large amount of current that MCB cannot bear the load as a sole fuse.
• MCCB has an adjustable trip which protects large powered motors from entering into the overloading stages. MCCB has high tolerability and tensile strength with high inrush powers that a large electrical motor can create.
• MCCB is also used to protect and run current generators which almost generate 100 amps.
• MCCB can protect the capacitor bank which is generally used for power factor correction in the current flow.

Different types of MCCBs

There are five different types of MCCBs which are mentioned below:

• Type B
• Type C
• Type D
• Type K
• Type Z

The Type B MCCB has the range of operating current which trips between three and five times in the overall rated current which is very much suitable for use in domestic applications along with the resistive load application with a lower amount of high current.

Type C MCCB trips between 5 and 10 times of the rated current input with response time from a minimum limit of 0.04 seconds and is suitable for commercial or industrial purposes with inductive load applications for moderate surge current.

Type D MCCB trips between 10 and 20 times the total rated current input along with a response time of a minimum 0.04 seconds and is suitable for inductive capacitive load applications such as motors or large vending motors.

Type K and Type Z MCCB trains between two and three times of the rated current input along with the response time of a minimum 0.04 seconds and is used for production of highly sensitive semiconductor devices.