short circuit or overload, the shutdown process results in an electric arc between the contacts of the MCB. The additional quick release for opening the contacts in the event of a short-circuit helps to keep the energy of the short-circuit to a minimum, which in turn keeps the ‘stress’ the wires are subjected to, as low as possible. In the event of a short-circuit, the current rises very sharply and the coil creates a magnetic field that both trips the switching mechanism and opens the contacts via a quick release mechanism. Short-circuit protection is located in the electromagnetic coil (green area). If the nominal current-the current the circuit breaker is designed for-rises slightly, the bimetal heats up to a greater extent and, after a certain period of time, this causes the switching mechanism to trip. Longitudinal section of a miniature circuit breaker (MCB) © ABBįor overload protection the temperature of a bimetal, through which the current passes (yellow area), is decisive. When we look on the inside of an MCB we can see how that actually works. The short answer: it protects wires from overloads and short-circuits. Even if your finger keeps the switch in the on position, the internal mechanism will trip and ensure safe disconnection of the overloaded circuit. Our ABB miniature circuit breaker will, thankfully, protect your wires from both overload and short-circuits even if the switch has been forced into the ON position, due to what we call a ‘trip-free’ MCB. In a pinch, you might even get the bright idea that you might be able to jam the switch in the ON position so that you can just finish vacuuming your apartment.Īnnoyingly, doing that won’t let you effectively clean your apartment nowadays. Moments later, the circuit breaker once again clicks to cut off the overload. So, you switch it back on, and off you go. Usually, ‘the cause’ can be located quite quickly: that ‘thing’ in the box on the wall is off. You’re annoyed, and you try to figure out what’s going on. The lights are out, the music is only playing in a couple of rooms or not at all, the washing machine and the dishwasher are off and the vacuum cleaner has fallen silent. Not long after, you hear a quiet ‘CLICK’ from the corner (or, in the case of older apartments, from out in the hallway).
![mccb circuit breaker mccb circuit breaker](http://www.nonarc.com/wp-content/uploads/2014/04/111.jpg)
#Mccb circuit breaker full
You’ve filled the dishwasher and turned it on, the washing machine is full of clothes and you’ve flicked the switch, you’ve pulled the vacuum cleaner out of its corner and plugged it in.
#Mccb circuit breaker Pc
In preparation, you’ve compiled your favorite MP3 playlist on your PC and it’s being streamed in all rooms. You’ve just decided to get your annual spring clean over and done within record time tonight. Just imagine you live in an apartment built maybe sometime in the 60s. However, if someone then asks what miniature circuit breakers, or MCBs, actually do, my answer might go a little something like this: When people ask me “What do you actually do?” I say “I work for ABB and am responsible for miniature circuit-breakers within product marketing.” Then, I either get perplexed expressions or a friendly “oh, right…” as an answer. Everyone knows what it is-but not everyone knows what it does.