In India, for home use, MCBs are made as per Indian Standard IS/IEC-60898 Part-1. If we go to market for purchasing then we usually come across two main types of MCBs, B-Type & C-Type. Let's see the key differences between them according to uses in our day to day life.
1. B-Type MCB-
Popularly known as light load MCB. Mainly used for non-inductive loads such as LED TV, Light, Fan, Exhaust fan, etc. B-Type MCB takes 5 times current to the normal rating of MCB for tripping in less than 0.1 Second. Example, B-Type MCB of 6 Amp MCB will take 30 Amps to trip instantly.
B-Type MCBs shall be used on the circuits of non-inductive loads only. Non-inductive loads require less starting torque and hence less current is required during starting of such equipments.
2. C-Type MCB-
Popularly known as Power MCB as they are used for power loads such as Air Conditioner, Refrigerator, Geyser, Mixer, Microwave Oven, etc
Inductive load requires huge starting torque and hence they take starting current of 4-7 times than the rated current of equipment. Hence, MCB installed on such circuits shall allow huge current to start the machine. Hence, "C-Type" MCB is used on power load circuit.
|Particulars||B-Type MCB||C-Type MCB|
|Popular Name||Light MCB||Power MCB|
|Useful for||Non-Inductive or Light inductive Load||Inductive Load|
|Tripping Current||5 times to the rated current||10 times the rated current|
|Equipment||Light, Fan, TV, 5 Amp Socket, etc||Air Conditioner, Geyser, Refrigerator, Washing Machine, Computer,|
Tripping current required:-
As per the information provided in IS/IEC-60898 Part-1 we can easily conclude that to trip the MCB in less than 0.1 second, the current required will be as per follow.
|Particulars||B-Type MCB (Amps)||C-Type MCB (Amps)|
|6 Amps||30 Amps||60 Amps|
|10 Amps||50 Amps||100 Amps|
|16 Amps||80 Amps||160 Amps|
|32 Amps||160 Amps||320 Amps|