A question for Elko about circuit boards

matula


Joined: 07/07/2008
Posts: 647

Message Posted:
14/07/2010 10:58

Elko, It is an internationally recognised standard that connections to a circuit breaker,contactor etc. have the line (supply) on the top connection and the load on the bottom connection. Why therefore are the connections on any distribution board that I have seen here (apart from my own which I have connected correctly) transposed so the load comes off the top of the breaker. Are the sparks here too dumb or lazy to take a piece of wire from the RCD/main breaker to the top of the CB row and then fit the bus link across the top?

Changing a breaker on a board here involves removing the bus link to get out the faulty breaker instead of undoing one connection and popping out the breaker.

While we are on the subject any 3 phase RCD I have seen here have the supply on the load side which renders the test/trip button useless.

I am speaking as a retired electrician of 40+ years experience.

Tenakoutou



Joined: 27/07/2009
Posts: 4110

Message Posted:
14/07/2010 11:06

I hope Elko will answer this question - excellent question, 'matula'!

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
14/07/2010 12:49

Matula,

I do not do any wiring but as far as I know all the contactors have a simple wiring diagram on the side which shows the line in at top and the line out at the bottom. It would not matter so much which way you connect a contactor as long as you do not take anything for granted and check if its live before you touch anything.



The matter is far more serious with the RCD. If wrongly connected as you say it will not trip when you press the test button but it will carry on giving protection against earth faults i.e. whicever way you connect it, there will be an inbalance in the coils if there is an earth fault and hence the breaker will trip. so not too fatal after all except that you cannot test it properly. Unfortunately most people never test it anyway

ismet

matula


Joined: 07/07/2008
Posts: 647

Message Posted:
14/07/2010 13:08

Thanks Elko, As you say not many people bother testing their RCDs. You are correct that it is not too serious about the contactor connections but the circuit breaker connections really annoy me when I see them!