# Does voltage drop on power cable depend on the type of MCB used

I am trying to figure out if there is a relation between the type (A,B,C..) of the MCB used and the total power cable length that can be used with it.

Resistance will increase with the increase in cable length which will increase the voltage drop on cable but will the voltage drop be the same if I am using two different MCB's, lets say one is 10A type C and another is 10A type B.

• Voltage drop across a length of cable depends on the characteristics of the cable which determine its resistance, and the amount of current flowing through it, not the circuit breaker protecting it. Apr 6 '17 at 13:47

(note: this answer is based on UK knowlage, I expect things will be similar across Europe, the USA has it's own standards which are very different from the European ones)

Volt drop in the cable depends only on the cable, there may be some volt drop in the MCB itself but I would expect it to be negligible. I've certainly never heard of anyone using it in design calculations.

However volt drop is not the only factor (or even the most important factor) in choosing a cable. There are three factors that need to be considered.