Answer / raghavendran

MCB's have tripping curves like B,Cand D.

Curve B type of MCB's are used where maximum sensitivity is
needed and the initial starting current is 3 to 5 times the
rated current.

curve c MCB's are used where close protection is not
required and the starting current is 5 to 10 times the rated
current.these may be used while tripping the circuit due to
high starting inrush current.

curve D MCB's are used where the starting current is very
high 10 to 20 times the rated current, like high capacity
motor installation where initial starting voltage dip may be
very high.

Answer / anil tandon

The MCBs are classified as per the Holding Currents and thus their usage are define accordingly,

B-Curve MCB:- They have a Holding current of 2 times of rated current and are used for Lighting Loads

C-Curve MCB:- They have a Holding current of 5 times of rated current and are used for motoring Loads.

The MCBs are classified as per the Holding Currents and thus their usage are define accordingly,

B-Curve MCB:- They have a Holding current of 2 times of rated current and are used for Lighting Loads

D-Curve MCB:- They have a Holding current of 10 times of rated current and are used for High Inrush currents E.g -Control Transformer etc

Answer / arshath

B curve using for domestic
C curve using for industrial

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