MCB/RCB question.

[AL]

I got a dedicated shower consumer unit with 1 MCB and 1 RCD. Now i'm having a problem understanding how it works. The connections are as follows: The earth in is connected to the earth out (straight through), the MCB has Live in and live out (live out is also connected to live out for the RCD) The RCD has Live in and neutral in as well as live out and neutral out. So if the RCD trips, it disconnects the Neutral? but the live remains connected via the MCB? But if the MCB trips and the RCD doesn't the supply is un affected? Is it the case that the RCD will always trip first and the MCB last? Confused?

TIA

AL

 

[breezer]

as you said The RCD has Live in and neutral in as well as live out and neutral out. if the rcd trips it does take the neutral out as well as the live, although the live is still physically connected if the rcd trips the live will be dead as well as the neutral.

an mcb is for overload / short ciruit protection, an rcd is for earth faults.

to find out how an rcd works see this

 

[AL]

sorry i realised i asked a silly question as soon as i'd posted it. (it was late at night to be fair ) Anyway, now my head is clearer i realised, the MCB is actually in series with the RCD not in parallel as i'd wrongly assumed, therefore if either trip the supply is cut.

I really must learn to think before i speak. Thanks anyways though!

AL

 

[ban-all-sheds]

In series will work much better..