Can ac mcb used as dc mcb?

Answer 1

you seem to have the answer to the question just make sure you use the right type as there are a couple of types such as a, b, c and d. C and D have much larger start up currents availble. Why not look at the back of the iee wiring regulations for more information. Eectricity entering a house is all ac and the dc comes into play through your appliance through the use of bridge rectifyers. An mcb operates through a coil being energised when there is no equilbrium between the incoming live and outgoing neutral detecting a fault within the circuit. So yes you can use any mcb never heard of a dc or ac mcb before.

Answer 2

Dc Mcb

Answer 3

You can use an AC MCB on DC.

The MCB contains two distinct types of circuit to monitor the current - Magentic, which responds to instantaneous overloads, and Thermal, which detects overload over a period of time depending on which curve the breaker is designed to.

Both these circuits will work on DC.

However - and this is where the major difference lies between AC and DC breakers - DC breakers have an extinguishing magnet (permanent) to pull the arc away from the contacts as they open, AC breakers rely more on the fact that the current will fall to zero as the voltage crosses from positive to negative so extinguishing the arc.

For this reason if you use an AC breaker on DC you will find that manufacturers de-rate the voltage that they can be used at, for example a breaker rated for 240VAC may only be suitable for use at 24VDC.

Answer 4

Yes, no problem at all.
The trip rating is reduced though, i.e. the MCB will trip at a lower current when operated at DC. This is because the trip current is based on the RMS current at AC, but with DC the RMS and peak current should be the same (barring any transients). So the DC tripping current will be 0.707 * the AC rating.

Cheers.

Answer 5

Yes you can use. But:
Normally DC voltage is 1/5 of the AC rated voltage of the Breaker. So it means if you have 220 volts rated breaker then 44 volts (round up 48) of DC. Because in AC will go every 10 mS (milli Seconds) to Zero in 50 Hz but in DC no break, so in DC the arc on contacts will go to a long distance as compared to DC which may melt more quickly the contacts than AC. At the same time, better, that the breaker specifications mention DC too.
https://www.electrikals.com/products/r/lv-switch-gear?cid=689&page=1&pagesize=15

Answer 6

The 415V MCB might work like a switch only and won't trip on its specified rating,