Moulded Case Circuit Breaker – MCCB

March 15, 2023by Binghalib Trading

Who we are

Established in year 1994 in UAE, provides Complete Solution for LV Switchgear Components

From panel builders, local independent contractors to major contracting companies, our sales network is well adapted to serve our markets, supported by the regional strength of one of the largest switchgear companies in the Middle East with over 40 years of proven track record,

We are one of the leading authorized distributors of industry leaders like ABB, LS Industrial System, Rockwell Automation, Clipsal with substantial stock to cater our customers. Our logistic and distribution team supports necessary material handling to ensure possible quickest deliveries on time. We are one of the leading LV switchgear components distributors in UAE.

Binghalib Trading, MCCB


What is MCCB

MCCB stands for Moulded Case Circuit Breaker. It’s another type of electrical protection device which is used when cargo current exceeds the limit of a atomic circuit swell. The MCCB provides protection against load, short circuit faults and is also used for switching the circuits. It can be used for advanced current standing and fault position indeed in domestic operations. The wide current conditions and high breaking capacity in MCCB find their use in artificial operations. MCCB can be used for protection of capacitor bank, creator protection and main electric confluent distribution. It offers acceptable protection whenever an operation requires demarcation, malleable load setting or earth fault protection.

Moulded Case Circuit Breaker – MCCB

Function of MCCB

MCCB as it’s an electrical protection device has the following functions

Protection against Overloading

Overloading is the condition when the current exceeds a destined limit for a specific duration of time. The overfilling current can damage the outfit, wirings and can produce fire hazards. MCCB offers protection against overfilling using a bimetallic strip.

 Protection against Short Circuit

A short circuit is a condition when the live line comes into contact with each other or with a neutral line. It can do due to downed lines or broken or exposed cables or deteriorated sequestration of cables. The current inflow due to the short circuit is veritably large and veritably destructive.

Short circuit current must be intruded in the shortest period of time. MCCB can trip short circuit current up 200k amps in the duration of0.04 seconds.

 Manual Switching

The MCCB can also perform homemade switching to switch ON/ OFF the power force to the circuit connected. It cande-energize the circuit in case of conservation.

Working Principle of MCCB

An MCCB protects a circuit from fault current. It uses thermal and glamorous mechanisms to break those fault currents. The thermal medium is used for load protection while the glamorous medium is used for short circuit protection

Load Protection

Load occurs when the current exceeds a limit for a prolonged duration. MCCB has a thermal medium that contains a bimetallic contact to cover from load. A bimetallic strip is made from two different types of essence having different rates of thermal expansion. Upon temperature change, the strip bends or contracts.

The main current passes through the bimetallicstrip.However, the connections toast up and expand, If the current exceeds a certain limit. Due to different expansion rates, the strip bends and passages the circuit.

In electrical bias, the current can load for short durations of time, it’s normal and shouldn’t be considered as fault current. thus, MCCB has a time detention that allows the load current for a short duration of time before tripping the circuit.

Short Circuit Protection

MCCB protects against a short circuits using a solenoid that produces electromagnetic force. The main current overflows through the solenoid that attracts and repels a plunger responsible for tripping the swell.

still, the solenoid produces a weak glamorous force that can not attract the plunger, If the current remains below the threshold. In short circuit conditions, a veritably high current overflows through the solenoid that generates a veritably strong glamorous force. It attracts the plunger that trips the circuit.

 Maintenance of MCCB

The MCCB is a dependable electrical protection device that requires veritably little conservation as it’s enclosed in a moldered covering and can not be opened. still, periodic conservation is needed to insure dependable protection by performing the tests mentioned above as well as visual examination and cleaning,etc.

 Advantages and Disadvantages of MCCB

  • MCCB has an malleable trip setting that allows it to be used for low as well as large currents
  • It can handle a veritably large current.
  • It can incontinently intrude veritably large currents.
  • It has a portable trip unit.
  • It has a veritably small tripping time therefore presto switching during fault current.
  • It also offers a remote ON/ OFF point.
  • It has a compact design and takes lower space.


  • MCCB isn’t suitable for high voltage operations.

• They aren’t suitable for domestic operations.

 Applications of MCCBs

Since MCCB can handle veritably high currents, they’re used for heavy- duty operations similar as in diligence.

  • malleable Trip Settings MCCB is superior to MCB and has further operation due to its advanced current running and malleable trip setting capabilities. It makes it protean to be used for high as well as low current settings.
  • Motor Protection MCCB is used in diligence to cover large electrical motors from overfilling. It offers malleable trip settings to tolerate the high flux current with necessary detention.
  • Welding Machine Protection Welding machines draw a veritably large quantum of current that an MCB can not handle. thus, MCCB is used for welding machines.
  • Electric Feeders Protection Due to its malleable setting and high current running, it’s used in electric affluent to distribute Power because it carries hundreds of amps that a normal MCB can not handle.
  • Generator Protection They’re also used for the protection of large creator that generates hundreds of amps.
  • Capacitor Bank Protection Capacitor bank is used for power factor correction. MCCB is also used for its protection against high currents.

Difference between MCB and MCCB

1 It stands for Miniature Circuit Breaker. It stands for Molded Case Circuit Breaker.
2 Rated current not more than 125 Ampere. Rated Current up to 1600A
3 Its interrupting current rating is under 10KA Their interrupting current ranges from around 10KA -85KA
4 Judging from their power capacities, MCB is mainly used for low Breaking capacity requirement mainly domestic. MCCB is mainly used for both low and high Breaking capacity requirements mainly industrial.
5 Its trip characteristics are normally not adjustable since they basically cater to low circuits. Its trip current may be fixed as well as adjustable for overload and magnetic setting.