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Light switch replacement

My light switch on the stairs was warm. I read to check all connections tight. There should be 3 brown wires in the com hole and one grey and one black in the L1 and L2 (I think). One of the brown wires was totally loose but looks like in was in 'com'.
I have replaced the switch and put the wire where they were in the old one. However, does 3 brown in one com switch sound correct?
All three switches on the stairs are now working correctly.

Where there are two switches ie in dining room, there are 2 brown wires in the com in one switch, I assume to link second switch. I therefore assumed the three described link the three switches? Is this not the case? The two switch situation described is like that in every room with two switches.

3 Answers from MyBuilder Electricians

Best Answer

Hey. 3 cables in your com is unusual. The com is your feed, that's where the power is always live. So there seems to be a some cables looping off and supplying other electrical equipment. If lights working then great. But maybe worth getting it looked at to determine what othere electrical points is fed from that switch. Hope this helps.


Answered 26th Oct 2012

if you have wired the switch and everything works then it must be right,some electricians use the switch to wire the loop instead of the ceiling rose and it is quite common to find in excess of 3 reds/brown cables in the common and you only have 1 r+black/brown+blueat the ceiling rose, the neutral wires are terminated in the ceilind/attic, regards Terry.


Answered 28th Oct 2012

Depending on the wiring method, (e.g. if its singles in conduit) could mean that there are more than one line conductor in the common terminal.

Alternatively the common could be on the load side and the three cables run off to separate lights? Without more info and seeing the installation its difficult to say if its correct or not.

Based on your revised question, where there are two gang switches, it is quite normal to have a link at the back of the switch to carry the live over to the next switch.


Answered 27th Oct 2012

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