MCB

MCB (MINIATURE CIRCUIT BREAKER)

Miniature circuit breakers have precision formed moulded case and cover of flame retardant high strength thermo plastic material having high melting point, low water absorption, high dielectric strength and temperature withstand.

The switching mechanism is independent, manual, and is trip free, i.e. breaker trips internally even if the operating knob is held on position.

The Arc-Extinguishing device comprises of 15 plates arc chutes\. The arc under the influence of the magnetic field and arc guide is moved into the arc chute where it is rapidly split and quenched.

The tripping mechanism is Thermal Magnetic type.

Thermal operation provides protection from moderate overloads. Under over load condition a thermo metal element (bimetallic strip) deflects until it operates a latching mechanism allowing the main contacts to open.

Magnetic operation

Magnetic operation, large overloads or short circuit current actuates a solenoid causing a plunger to strike the latching mechanism rapidly opening the main contacts.

The Fault current breaking capacity -9KA. They may be used instead of fuses on individual circuits and are usually backed-up by fuses in the main feed to the distribution board.

                                   

Colour identification-

Knob colour	Series name	Application
GREEN	L	Lighting
BLUE	G	Motors
BLACK	DC	DC circuit
RED	Isolator	Isolation

Selection chart for house hold appliances-

Application	Watt, 230V,AC	MCB rating	Series
Air conditioner	1.0 tonnes 1.5 tonnes 2.0 tonnes	10A 16A 20A	G’Series
Refrigerator	165 litre 350 litre	3A 4A	G’Series
Oven cum griller	1750W 4500W	10A 32A	L’Series
Hot plate/room heater	750W 1000W 2000W	6A 6A 10A	L’Series
Washing m/c	300W 1300W	2A 8A	G’Series
Water heater	1000W 2000W 3000W 6000W	6A 10A 16A 32A	L’Series
Electric iron	750W 1250W	6A 8A	L’Series
Toaster /kettle	1200W 1500W	8A 10A	L’Series