POINTS TO REMEMBER
No. of circuits should be selected in such a way that the load variations on each circuit during the day are not significant. For heavy load equipment/ appliances, individual MCB should also be provided.
Current carrying capacity of all the elements of the circuit should be matching. For example, if the total installed load in a circuit is 16 Amp, then rating of MCB should be 16 Amp and wire size (2.5sq mm) should also be selected accordingly. Otherwise MCB will not serve the required purpose. If higher rating MCB is installed in this circuit, it will not provide overload protection.
Quality of the material used in the circuit is equally important. If the quality of even one material, say wire, is sub-standard, it will reflect on the performance of other parts of the circuit like MCB which may otherwise be of very good quality. For example, in case of short circuiting, poor quality wire will burst/burn out first before the MCB trips.
Function of RCCB is to give protection against any leakage of current, which may result in electric shock. Whereas MCB is safety switchgear for protection against short circuit and overload. Therefore both the safety devices should be installed for fool proof safety
If MCB frequently trips, it is an indication of fault in the circuit. In such a situation, you should immediately call an expert electrician to rectify the fault.
Loose connections result in sparking which may damage the switchgear / prove hazardous. Therefore the wire connections should be tight (no loose strands) and preferably be made by using lugs/thimbles
‘B’ category MCB is used for heating load (geysers, heaters) in the circuit whereas ‘C’ category MCB is used for inductive load (motor, air conditioners). Selection of wrong category MCB will adversely affect its performance
The electric installations should be protected from rain water/dust to avoid damage and to ensure safety
All Electrical equipments should be properly earthed
MCB SELECTION CRITERIA
|APPLIANCES||CAPACITY/ WATT ( LOAD) AT 240~ SINGLE PHASE||MCB RATING|
|Air Conditioner||1.0 Ton||10A|
|Cooking Range||With oven cum griller 4500 Watts||25A|
|With oven cum griller 1750 Watts||10A|
|Oven only 750 Watts||6A|
|Hot Plate only 2000 Watts||10A|
|Room Heater||1000 Watts||6A|
|Geyser (Storage instantenous)||1000 Watts||10A|
|Washing Machine(Automatic)||1300 Watts||6A|
|LCD & LED TV||750 Watts||6A|
|Photo Copier||1500 Watts||6A|
|Electric Kettle||1500 Watts||10A|
|Mixer Grinder||1000 Watts||6A|
|Electric Iron||1250 Watts||6A|