Originally Posted by Artikbot
I don't know what on Earth you guys have as electrical installations, but in every net I've installed together with my father the RCD will trip even if you're on a subsection governed by a separate MCB. It has a much slower arming time than the MCB, but if you don't reach the MCB SC rating, the RCD will trip. And it should, for your safety!
Still 30mA (ones over here are rated at 30-35mA too) hurts like all freaking hell if it crosses a large body section.
Well I lost track of the conversation , simply a RCD will only activate when there is a current flow to earth from someplace it shouldn't as this causes a imbalance on the L/N wires tripping the RDC , a MCB will operate on a earth fault if the current is high enough to trip it , but when it involves people it usually is not - hence the reason we use a RCD instead , The other fault a MCB will operate on and a RCD will not operate on is a Line fault between any line conductors , L - N only as the RDC wont see any fault as all current is still flowing though the L/N conductors
The RDC or multiple RCDs for different circuits monitors all current going in and out of the circuit/circuits , if what's combing back on the Neutral isn't the same as what's going out on the live it will trip
someone said " what if the house didn't have a RCD " well then if it didn't and there was a short to earth though a human and the current wasn't enough to trip the MCB , which in the case would have been a 32 A for the ring final sockets , and a human in most cases wouldn't generate that much of a fault current ( even on a 6A MCB ) would continue to be electrocuted till the supply was turned off , once again reason RCD are always placed in homes .Edited by TwirlyWhirly555 - 8/30/13 at 5:03am