Common light fitting problems

funkydung · Posted: Mon Jan 26, 2004 10:16 am Post Subject: Common light fitting problems

Hello there. The light no longer works in my bathroom. I though the bulb had gone but it hasn't - no bulb works in the fitting. Looking at the fitting itself - all the wires are connected tightly: 2 red (wond together and attached to on screw) and two black (each attached to their own screw). The springs in the fitting seems to be fine to - the connection is good. However, when i had a look at the fitting it seemed quite old, dusty and loose. I vaccumed it to get rid of the dust.

Does anybody know if light fittings tend to die after a number of years? I've yet to buy a new fitting but wonder if I can fix the existing one? If its not the fitting that is at fault, where else should I look? All other lights in the house are working fine. I've also opened up the switch and all the wires are correct and firm.

Does anybody have any suggestions as to where my problem might lie?

Thanks in advance.

breezer · Posted: Mon Jan 26, 2004 6:35 pm Post Subject:

its a new one on me, but if you do get a new light fitting, make sure its suitable for a bathroom, and note my signaure

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il78 · Posted: Mon Jan 26, 2004 7:08 pm Post Subject:

If its not the light in the bathroom it could be the light fitting before (ie, lights wired in a loop in method) check the connections in the hallway landing or the bedrooms etc.....

Have you got a voltage tester?

yankey-sparky · Posted: Mon Jan 26, 2004 7:09 pm Post Subject:

Do you have a voltage or continuity tester? Does anything else fed on the same circuit work?

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funkydung · Posted: Tue Jan 27, 2004 9:01 am Post Subject:

Thanks for the advice. Yes i do have a voltage tester. I haven't tested anything yet but i will. My new fitting seems to be a replica of the old one though it doesn't proclaim to be specifically for a bathroom.

The weird thing is that the wires that come through the ceiling are TWO red and TWO black (as well as an earth)! This is as opposed to the one red, one black and and earth. The previous owner of the house has wound two reds together and attached them to one terminal and then put the other two blacks in seperately. The earth is attached to the shell of the fitting. Seems strange and contrary to any diagrams ive ever seen. Anybody seen this set up before and if so, why is it done like this?

With regarding to testing with my continuity tester... Is it better to turn the electrics off completely at the mains or is it ok just to turn off the lighting ring? Most advice i have says turn off at the mains which i take to maean the whole electricity for the house. My consumer unit has flip switches. The reason i ask is that when i leave for work it's pitch black and when i come home it's pitch black! So some other light source would help (a plugged in lamp for example) Otherwise i'll have to resort to using a torch!

securespark · Posted: Tue Jan 27, 2004 11:06 am Post Subject:

Funkydung

(where the heck did you get that name??)

Are the two reds connected to the light fitting terminals are are they just connected to each other and not to anything else?

If they are on their own, then I suspect that this is the live feed in connected to the live feed to the switch.

The other black ones will be: one neutral from live feed cable and one switch wire (live when light on) from the switch cable which has not been marked with red to show it is a live conductor, not a neutral.

Please don't take my word that this is correct - make some careful tests with a meter or tester to see what's what.

Try putting the meter across the two blacks and see if you get 240V with the bathroom light switch in the on position.

funkydung · Posted: Tue Jan 27, 2004 12:03 pm Post Subject:

Securespark. Funkydung is the name of part of the atom heart mother suit by pink floyd. I just thought it was kinda cool and used it as my username.

The two reds are attached top each other and to one of the terminals. The two blacks are seperate and attached to seperate terminals - one each. The bayonet fitting has three terminals. If i were to wire the replacement baynet fitting in the same way the two reds would be in the EARTH terminal and one black each in the other two terminals. Now that just can't be right can it?

I guess i could try to copy the existing setup with the new fitting - what harm could that do?

IanDB · Posted: Tue Jan 27, 2004 1:50 pm Post Subject:

I reckon securespark is right. Draw this out on a piece of paper and you will see the logic. One red is live coming in, the other red will go to your switch. One black (switched live) will come from the switch to one side of the bulb, the other side of the bulb is neutral and is paired with the first red. It sounds as though this is either the last light in your circuit or it has been wired in a radial manner. I'm not going to comment on your wiring but it may be worth getting it checked if you don't know what you're looking at.

That's the easy bit. What worries me are the connections on the actual light fitting. YOU DO NOT PUT RED WIRES INTO THE EARTH TERMINAL!! If the worst comes to the worst use a terminal block to connect the two reds together leaving the two blacks to go the correct terminals on the light fitting.

Sorry, but it sounds a bit iffy to me. I await other comments with interest.

funkydung · Posted: Tue Jan 27, 2004 2:04 pm Post Subject:

Quote:

YOU DO NOT PUT RED WIRES INTO THE EARTH TERMINAL!!

Yep - that's what I thought. Sounds a bit daft to me too. Seems like the previous owner just put them there out of the way!

I'm guessing that there isn't a junction box where perhaps there should be! There isn't a rose either! So, in order to make do, the two reds were wound together and just dumped in the earth terminal. Lots of bodging makes it difficult for me to work with. Cheers for that.

Maybe i should get a sparky in after all.

breezer · Posted: Tue Jan 27, 2004 6:38 pm Post Subject:

if the lamp holder is a "batten holder" it doesnt have an earth terminal, it DOES have a loop in terminal (bigger than the others) which is used for looping in and out the live, which is what it sounds like is the case here

edited to add picture

this is an earth connection plate for a batten holder

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Millennium_Boy · Posted: Tue Jan 27, 2004 8:35 pm Post Subject: Bathroom Light

Why not take the opportunity to fit an Enclosed Splashproof Light fitting (CE Marked) in the bathroom for maximum safety?

funkydung · Posted: Wed Jan 28, 2004 9:24 am Post Subject:

Breezer, i think you are right. I think i do have an earth connection plate up there. This is what the current earth wire is attached to.

And below that is the rest of the fitting: 2 black wires and two red wires. I imagine you are correct. This is very useful stuff and I shall investigate further...

By the way, this is pretty much what i have purchased:

There is a plate left from the old fitting that i can attach it to. However, should i have bought this

breezer · Posted: Wed Jan 28, 2004 9:47 pm Post Subject:

if it aint broke dont fix it, use the earth connection plate that is still there

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funkydung · Posted: Thu Jan 29, 2004 11:30 am Post Subject:

Cool, i'll do that. Now, what about those two red wires? Any idea what to do with them?

For handy analysis, I've created a little image. Note that the original fitting does not have the earth marking on the third terminal. The new one does.

here's my diagram:
Many thanks for your help. Due to being snowed in yesterday I couldn't actually get home to sort the problem out anyway!

breezer · Posted: Thu Jan 29, 2004 6:50 pm Post Subject:

from your drawing i would say that yes it is a batten holder with a loop in terminal. you should put the two reds into a connector block

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