mccb and elcb

What is MCCB?

MCCB is an electrical safety device used to safeguard circuits from excessive overload or short circuits by switching circuits. These devices are used when the current load exceeds the limit of MCBs (Minature Circuit Breaker)

Functions of MCCBs

•           Overload Protection,

•           Electrical Fault Protection against short circuit currents, and

•           Electrical Switch for disconnection.

We supply 1Pole, 2Pole, 3Pole and 4Pole MCCBs at the best prices and discounts online. Shop for good quality MCCBs from ABB at

Ranges of MCCB 

T8                    Up to 3000A, 600V AC -up to 125ka at 480 V-3, 4 pole

T7                    Up to 1200A, 600V AC-up to 100ka at  480 V-3, 4 pole

T6                    Up to 800A, 600 VAC /DC-up to 100ka at 480 V- 3,4 pole

T5                    Up to 600A, 600V AC/DC-up to 150ka at 480 V -3,4 pole

XT4                 Up to 250 A, 600 VAC/DC -up to 200ka at 480 V -3,4 pole

XT3                 Up to 225 A, 480 V AC/500V DC- up to 65ka at 480V-3,4 pole

XT2                 Up to 160 A, 600 V AC/500V DC-up to 200ka at 480V-3,4 pole

XT1                 Up to 160A, 480V AC/500V DC -up to 100ka at 480V-3,4 pole

A2                    Up to 250A, 240v AC/250V DC-up to 25ka at 240V -2,3 pole

A1                    Up to 100A, 240 V AC/250 V DC -up to 25ka at 240V-1,2,3 pole

P1                    Up to 160A ,36KA 415V 3 pole and 4 Pole (Formula DSP MCCB)

P2                    Up to 250A ,36KA 415V 3 pole and 4 Pole (Formula DSP MCCB)

Standard MCCB Accessories

Extended spreaded terminals

Separator – PB and Low insulating terminal covers – LTC

Extended Rotary handle operating mechanism

Spring charging motor- M, Stored Energy Motor Operator – MOE and Motor operator with direct action

available in 24, 48.60, 100…130V, 220…250V and 380…415V AC/DC.

Auxiliary contact Electrical signals

Shunt opening and closing release

Under voltage release – UVR

Time delay device for under-voltage release- UVD

Key Lock & Pad Lock– KLC

Key Lock for Rotary Handle – RHL

Key lock for motor-operated- MOL

Mechanical interlock

Plug-in and draw out conversion Kit

Residual current devices

Circuit-breakers for AC and DC power distribution;

Circuit-breakers for zone selectivity;

Circuit-breakers for motor protection;

Circuit-breakers for application up to 1150V AC and 1500V DC;


SACE Tmax T – PV

ABB has bought a newly advanced MCCB (Molded case circuit breaker) for its higher-voltage solar power plants to its Tmax PV range. The breaker is the latest addition to ABB’s complete range of protective solutions for its utility-scale solar plant. It is designed to protect – combiners, switchgear, and inverter up to 1500V DC.

Motor protection

ABB solutions for Starting, switching, and protecting three-phase asynchronous motors are basic operations for their correct use. ABB SACE entails two different type of solutions for this application: –

A traditional system:  which foresees a circuit-breaker for protection against short-circuit, a thermal relay for protection against overload and missing or unbalanced phase and a contractor for motor switching; 

A system of integrated protection: thanks to the Ekip M-LRIU trip unit, which ensures both protection against short-circuit, and against overload, as well as that against Motor Circuit-breaker with magnetic

A system of integrated protection enables both protection against short-circuit, against overload, and motor circuit-breaker with magnetic only release Thermal relay Contactor PTC PR212/CI Motor Circuit-breaker with electronic release Ekip M-LRIU Contactor Protection against short-circuit Integrated protection missing or unbalanced phase and that against the rotor block.

While selecting these devices, one must take different factors into consideration:

  • Motor power
  • The diagram and type of starting
  • Type of Motor – Cage Rotor / Wound Rotor
  • The fault current at the point of the network where the motor is placed.

Specifications of MCCBs:

•           Ue – Rated Operational Voltage.

•           Ui – Rated Insulation Voltage.

•           Uimp – Impulse withstand voltage.

•           In – Nominal Rated Current.

•           Ics – Service Short Circuit Breaking Capacity.

•           Icu – Ultimate Short Circuit Breaking Capacity.

MCCBs are now available with 2 kinds of release – Thermal magnetic and Microprocessor release.

The principle used for Thermal-magnetic is of the bimetal and electromagnetic coil. MCCB tripping can be caused in transient peak as electromagnet is a peak sensing device thus thermal protection is required for O/L and electromagnetic or solenoid for S/C. Thus CB gives the following protection –

  • Thermal / Overload protection – Through Bimetal
  • Electromagnetic / short circuit protection – Through Electromagnet
  • Under Voltage protection by U/V release

The microprocessor is capable of simulating and calculating peak values of the true RMS value of current through the microprocessor. Below protections are offered by microprocessor-based release

•           Earth Fault

•           Neutral protection

•           Instantaneous Over-ride

•           Earth Leakage

•           Current Unbalance

•           Overvoltage

MCCB Maintenance

To ensure efficiency in its operation, regular maintenance procedures are to be followed which include visual inspection, lubrication, cleaning, and testing.