Hi All Hope I'm not the only one whose mind goes blank looking at wiring diagrams. Took the old plastic bathroom ceiling light down but, on yanking the wiring through the lath and plaster, ended up with this little lot (plus a 6" length of black cable attached to nothing). Don't know where the spare black cable in the pic came from, or the loose one.
[IMG]
formatting link
As is, we have power if I wire a lamp up to the terminal blocks but the pull switch doesn't turn it off. Very difficult to trace wiring any further without serious disruption, so a degree of trial and error would be ok. The earth will be sorted out of course because the new fitting has a metal base, but any other thoughts appreciated.
Wire the bulb between the spare black wire and terminal 'D'
The spare black wire is likely to be the live return from the switch and ideally should have had a red sleeve over it to show it has been reused as a switched live connector.
The whole lot wants to go into an enclosure too - chock blocks are not permitted to be used like that and you have only single insulation on the wires.
However that is all easily sorted with one of these:
formatting link
which will give you neat maintenance free terminations and cable clamps. It does not need to be fixed down (but you can screw it to a joist of you want). It is designed to be shoved through a hole in the ceiling...
Now, back you your main question.
Looks like:
C is the incoming supply neutral and 2 other supply cables leading off to other lights.
D would be the lamp neutral.
A contains the incoming supply live and 2 lead offs to other circuits. Also contains the live to switch for this lamp (the cable with the dangling black marked ??).
B is not used.
The dangling black marked ?? is the switched live and goes into this lamp. It should be sleeved red (well, brown now, but it hardly matters - red for consistency, brown if that's all you have. A couple of turns of red or brown insulation tape is sufficient too.
The earths need sleeving with green/yellow sleeve - tape is not sufficient.
You should be able to verify all the above with a multimeter and someone else poking the switch - but do stick a terminal on that floating black for the moment to give it some protection - it's live.
Wiring looks OK superficially - it's just a crap half arsed termination that's the problem...
Thanks guys. Just relieved it was that simple. And yes, Tim, I will do the whole thing properly. Now I've cut the floorboard and have direct access, there can be no excuse
This is the main reason why, when laying out lighting circuits, I use junction boxes so that each outlet/switch/etc has a single unambiguous cable coming to it. Two-way switches have a single which is always the common and a twin, /for each switch/, or I use some of my drum of triple+E cable.
Normally the lighting feed from the CU 6A fuse bridge is daisychained from ceiling rose to ceiling rose with a switch drop from each ceiling rose.
See here for a clear wiring diagram of this arrangement:
However, what you have here is a third B (assuming that the mains feed goes from left to right), which is a spur off the daisychain to provide another ceiling rose with a permanent LN&E feed.
The only silly thing (I've only just spotted) is the improbable use of a specially colour coded T&E switch drop cable. This is more likely to be just another length of FT&E (in old money Red, Black and bare copper protective earth) with the black used as the switched live return with a red sleeve to warn that this is the case (incidently, also acting as a switch drop label if all three (or, in this case, four) cables are disconnected from the ceiling rose terminal block).
In this case, the chocolate blocks are standing in for those connections normally found in a ceiling rose which has obviously been displaced by the ceiling mounted luminaire (which, incidently, should also have an earth connection if it has any metal parts deemed to be a shock hazard, indicated by there being an earth terminal in the luminaire itself).
Curiously, I notice the mix 'n' match between the old and the current colour coding of the cabling and the pendant lamp holder flex. The absence of an earth wire is entirely normal for such pendant lamp sockets. However, if you choose to hang a metal chandelier off the ceiling rose, it should be wired with a 3 wire cord with a green/yellow earth wire which should be connected to the earth terminal in the ceiling rose (marked '9' in the diagram) but in this case, joined to the bunched earths, preferably using another chocolate block if you're rewiring this on the cheap.
One other thing, the diagram implies that the wire entries into the screw terminal strips can go in either way. Normally they can only go in from the same side, including the blue and brown wires of the pendant cord which is usually routed around strain relief posts to go into the connector blocks on the same side as the cabling conductors.
One hopes that the loose black if that is really what is meant, did not pull out of the switch end or some interesting rewiring will be required. Brian
I guess the ease with which the guys on here diagnosed the problem suggests it's a relatively normal setup. Thanks for the diagram which I shall file for information. Whenever I've fitted luminaires and various gin palace light fittings I've always tried to keep the ceiling rose, if only because they're so fiddly to work on.
I am the same I have to re draw them with the items in the correct position on paper then draw the cable and at the end of each cable the colored wire going in to each item. I just cant follow it easily from a proper wiring diagram.
You should see my wiring diagram for 2 PIRs and 2 lights being fed from the mains!
Then I have to try and re draw it so it makes more sense to others to put on here to confirm I wont blow myself up.
I would say a big thank you to guys on here for time and patience given for my various `projects`
Ha ha. Bit rich coming from a man replying to a two year old thread. Who doesn't know that sentences begin with a capital letter. Who doesn't know that "ive" has a capital I and an apostrophe. Who doesn't know that the contracted form of "you are" is "you're".
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.