HRC fuse V/S MCB

It really rather depends - an MCB can be reset by an ordinary person, while to change a fuse requires tools and some knowledge, though nothing that could not be taught in an afternoon, Of course usually it only operates if there is a fault, so some knowledge is needed to fix that before resetting anyway...

MCBs have small mechanical parts that my corrode, freeze or greases that can stiffen in cold weather. A fuse will always operate, and may last for many decades without becoming unreliable !

Round here a special key is needed to open the box at the bottom of the lamp, and inside they are fuses. But boxes that supply things like advertising panels, that are more complex than a lamp, ballast  and holder and may split the supplies into more than one load, often do have MCBs...

Mike.

Many thanks for you reply Mike, for discrimination does the fuse option sounds better than using MCB ?

It rather depends what it has to discriminate with -  cascaded breakers like MCBs that are more or less instant above a certain current level  tend to all trip together if the fault current is enough to operate the largest one, then all the other will go as well.

However larger programmable breakers like you find protecting industrial settings can be tweaked so that there is a definite firing order for faults of different magnitudes.

Fuses are easier as they tend to have an almost constant let-through energy over a wide range of  fault currents, and if you have I²t data available then you can be quite confident what will happen in any given case.

As a rule of thumb with a few exceptions you can be pretty safe assuming that two fuses of a given design will discriminate nicely if the bigger one is more than 3 times the current rating of the small one.

In the UK this thinking lead to the 100 A company fuse feeding 30A BS3036 30 amps in the consumer unit feeding sockets and spurs fused at 13A or less. The rise of the 32A MCB now means that often for a dead short fault the 32A  trip will fire and the 13A fuse remains intact. That is progress for you.

Mike.