Kitchen lighting conundrum

[theChardmoneypit]

Hello, I'm a newbie to this forum (my first DIY forum) but I've used other subject forums before so hopefully I won't annoy anyone with my first post...

I've had a good look through the Wiki and at other posts and can see lots of similar questions but I'm not able to apply the discussion to my problem so here goes.

We moved into a dilapidated 1930's semi 4 months ago and "everything" needs doing.

I gutted the kitchen and now have just a few bits of cosmetic work to do after a full refit.

Lighting; there is one double switch in the kitchen and two independently controlled ceiling lights.

Both kitchen lights were simple pendent lights. I am replacing them with IKEA three-bulb units (for information only of course as they simply have a live and neutral choc-block connection in them).

I have replace one as it had a "new" ceiling rose and I simply remove the short two-core cable that formed the pendant "drop" and replaced it with a longer piece that allowed me to fit the new light unit.

Then I moved to the other light and here I made my mistake. I removed the pendent cable without fully paying attention to where the red and black cables were connected.

Now I can set it up so that:
- The second light is on all the time but I can turn the first light on and off.
- The second light is off all the time but I can turn the first light on and off.
- My third attempt blew the fuse! So I took the pendant cable away!

I have looked at a number of written and pictorial guides.

But I can't make them "look" like my setup.

I have put three photographs into my album named Kitchen lighting. The first two pictures show the inside of the very old ceiling rose. The third picture shows the inside of the light switch.

So, starting with the switch it is very simple with two red/live cables and two black/neutral cables.

The ceiling rose has two pieces of twin & earth coming to it. It has three pairs of connections.

The two red live cables are twisted together and in side of one pair of connections.

The earth cables are connected to the earth.

I believe that the two neutral/black cables were not twisted together.

I have now confused myself about where they were but I believe they were in different pairs of connections to each other.

So the question is, where do I put each of the two neutral/black cables (I realise it will be guess work as to whether we should label either black cable as 1 or 2) and then where to I put the new blue and brown cables for the new light?

Please bear in mind that this setup worked fine (i.e. each switch turned on one of the ceiling lights) before I took out the pendant and forget how it was connected.

I have not changed anything in the switch nor in the other (first) light.

Any help would be so gratefully appreciated.

Thanks

Chris

 

[chivers67]

Have you got a multi meter of any description?

 

[theChardmoneypit]

Sadly not, other than my finger...

 

[PrenticeBoyofDerry]

Sadly not, other than my finger...

Not a clever idea.
Looking at you photos, you have a
*live loop reds
*neutral black
*switched live black (this should be sleeved).
Does the old fitting indicate what the the cables terminated at this ceiling rose are? as this could be helpful.
I would suggest that the reds stay as they are with nothing else connected as this is loop between permanent live and switch.
Then one black(should be sleeved to indicate it is live) when the switch is closed, will become live this is your switch live and should be connected to the live of the new fitting and the black that does not become live is the neutral and should be connected to the neutral terminal of the light fitting.
Ideally you should have some approved test equipment to follow the correct testing procedure prior to energising circuit.
The earth go to earth terminals and should be sleeved green and yellow.
Your first light that you have connected is this a metallic fitting and does it require an earth connection, as you will not get this from a two core flex.

 

[theChardmoneypit]

Sorry for the silly comment, I certainly won't be using my finger!

Thank you for your time considering this for me.

I have looked very carefully at the fitting but there is no indication as to which is the switched live. Unfortunately it is simply two peices of twin and earth, so neither black has any mark, sleeve or indication on it (nor dies either red for completeness).

I can head to B&Q (only store near us likely to have a multimeter) tomorrow, if I did, how would I test to find the switched live (as in, step by step, where would I place the two diodes?).

Your description is really very clear thank you. I guess I could simply try the new brown with one black and the new blue with the other black and either:
- I will pop my fuse wire again if incorrect.
- I will discover that all works as it should.

Or am I being foolhardy here?

Both new lights have metal cases. Should I take a length of suitable copper wire from the current earth screw in each of the roses to a section of the inside of each of the metal cases?

I feel that I'm nearly there! Thank you again.

 

[theChardmoneypit]

Hi again PrenticeBoyofDerry,

I had a think about what I had asked and took the plunge.

Whether I put brown to one black and blue to the other, or switch to brown with the other black, etc. the 2nd light does not come on.

The first light (already up) works either way.

I ahve checked that I haven't blown all the bulbs by switching a couple and that is fine.

Does this help or hinder your thoughts?

 

[PrenticeBoyofDerry]

Hi theChardmoneypit,

The light would normally function as you have explained in your second post, regardless of which way you connect the Black conductor(switch live) Black (neutral) to the blue/brown conductors of the fitting. ,
as the lamps/bulbs are functional under reverse polarity.
But depending on your lamp holder type, this would be considered dangerous if the live terminal can be easily touched when the lamp(bulb) is withdrawn. So finding the correct the switch live is important.

But as this is not working anyway we need to do some further investigation, are you sure there was only one set of cables at the light that is working? You have not by accident loosened, disconnected something that maybe within the ceiling void?
Also a test for voltage at the faulty light could help us.
You can do this by the means of a multi-meter using the AC voltage setting, testing between the reds and earth, and each black and earth.
As you have stated that your fittings are metallic, so I assume they require an earth connection (if they not double insulated, class II equipment)
So either an earth connection must be made to the fitting via the hardwiring of your installation.
For safety concerns I would suggest that a continuity test is made to confirm that your earth (CPC/circuit protective conductor) is continuous between the earth terminal of the new light fittings and the consumer units main earth terminal, otherwise the connection will offer no protection.

 

[theChardmoneypit]

Right then, I've got a few jobs to do then I'll be off to B&Q for a multimeter. I suppose cheapest is fine for me, I can't see that I'll need to be checking current levels of AC supply which seems to be the added function by spending a little more...?

I am quite sure I haven't missed/dislodged any cables, however, I'll take a really good look and come back to you once I've got the meter and had a check as you have suggested.

Thanks again.