MCCB in Electrical: Types, Ratings and Working Principle

By September 4, 2019Articles
MCCB - Merlin Gerin - Compact NSX 3 poles 3P3d

MCB basically means miniature circuit breaker as it is used for up to 100amps in the motor feeders. MCCB (full form: moulded case circuit breaker) is used for 250 amps to 800 amps in the motor feeders. This system of circuit breaker basically protects the entire electrical system from overloading and having such conditions of short circuit issues. To simply put it these are the electrical protection gadgets that are used mostly with a wide range of voltages as MCCB which are commonly known have adjustable trip settings and can hold as much as 2500 amps in current ratings. A miniature circuit breaker also known as MCCB is the gadget that automatically switches off electrical circuit during an abnormal condition of the network which can mean in overload conditions, as well as faulty conditions which nowadays it is widely used in low voltage electrical network instead of the usage of a fuse as the handling of an MCB, is electrically safer than the usage of fuses.

MCCB working principles and its applications

The MCCB system uses a temperature-sensitive device also known as the thermal element along with a current sensitive electromagnetic device which is also known as the magnetic element in order to provide the overall trip mechanism which is relied for protection and isolation purposes. The MCCB basically utilizes a temperature-sensitive device which is also known as the thermal element with a current sensitive device are the magnetic elements to provide the protection and isolation which enables the MCCB device to provide overload protection along with electrical fault protection from any type of short circuit situations and also electrical switch for immediate disconnection.

What is a MCCB

What is a MCCB

As per the fact of overload protection is provided by the MCCB system via the temperature-sensitive components that are inside which is essentially a bimetallic contact. A contact of such type which basically consists of two metals that expand at different rates when exposed to higher levels of temperature and during the normal conditions of operation the bimetallic contact will be able to allow the electric current to flow through the MCCB system. When the total value of current exceeds the amount of trip then the bimetallic contact will start to heat up and bend away due to different thermal rate of heat expansion limits towards the chemical construction. Eventually what will happen is that the contact will end up to such a point that it is physically pushing the trip bar and also unlatching the contacts causing the circuit to be interrupted and also provide protection towards the entire electrical system from any type of unwanted situations.

As per the electrical fault protection against short circuit currents the MCCB provides and quick response to a short circuit fault which is based on the principle of electromagnetism. When a short circuit fault has occurred inside the entire electric circuit a large current begins to flow through the solenoid and as a result a strong electromagnetic field is established in there which basically then attracts the trip bar and opens the contacts.

Also in addition to all the tripping mechanisms, MCCB can also be used as a device for manual disconnection switch in such case of emergency or even any type of maintenance operation as an arc can be created within the range when the contact opens from each other.

Different types of MCCB

There are five different types of MCCB:

  • Type b
  • Type c
  • Type d
  • Type k
  • Type z

As the type b MCCB has the range of operating current which trips between three and five times in the overall rated current along with the operating response with 0.04 seconds of minimum and maximum limit of 13 seconds. Which is very much suitable for domestic applications along with the resistive load application with a lower amount of surge current.

MCCB - Merlin Gerin - Compact NSX 3 poles 3P3d

MCCB – Merlin Gerin – Compact NSX 3 poles 3P3d

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 maximum limit of 5 seconds combining the application suitable for commercial or industrial purpose 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 maximum limit of 3 seconds combining the purpose of commercial or industrial applications along with the suitability of inductive capacitive load applications such as forms or 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 to a maximum limit of 5 seconds which is basically highly sensitive to short circuit and are mostly used for production of highly sensitive devices such as semiconductor device is making it suitable for medical instruments along with the surge current level of very low at the subsidiary of distribution board for IT equipment.

MCCB - Merlin Gerin (EasyPact CVS) - CVS100N TMD 16A 3P3d - 3 poles (3P3d)

MCCB – Merlin Gerin (EasyPact CVS) – CVS100N TMD 16A 3P3d – 3 poles (3P3d)


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Differences between MCB, MCCB, ELCB, and RCCB

Where can you buy Schneider MCCB?

There are a lot of electric equipment retailing and wholesaling companies that are going to provide you with just the exact thing that you are going to meet with your purpose. One of the most popular MCCB manufacturer known as Schneider electric, are giving you all of the options that you are going to have for the purposes of you. You can easily check for the right product that is going to be helpful in terms of protecting your electrical equipment. Depending on what type of MCCB that you are buying it can be starting from 6 US dollars from up to more than a hundred. For example the basic type c MCCB that is used in domestic purposes can easily be priced between 5 to 8 dollars as the commercial purposes MCCB can be priced up to a minimum of 80 or 90 dollars.