In an mcb, it will be marked as, say C16,What does C stands for?? 1). Insulation level 2). Voltage class 3). Tripping curve 4). Heating curve

3 tripping curve there is b,C,d curves for tripping,B is most sensitive, C is normal range and D withstands the highest surges. 

3. FOR SELECTION OF TRIPPING CURVE WITHSTAND CAPACITY