Wiring new ceiling light LED

binft

Hi,

Sorry for all the new posts but i'm a new homeowner and this is a good place to come for potentially simple questions 

Anyway, I've bought a new LED flush mount ceiling light (the old one wasn't LED) and i'm looking at the wiring. I assumed it would be a normal 12v live and Negative connection but after taking the old ceiling light off i've got these cables.



My first thought is ofc to test the two black cables to see which is the live and negative but just my luck that the batteries are dead for my multimeter and I don't currently have any. Anyway it seems like only the two black wires were connected to the old light and i've found two more red ones tucked up out the way, which should I be using? Shall I just test the black cables and use those for the new light connection?

DB1904

Looks like someone's used a choc block and masking tape. Do you have a EICR?

I would be concerned about what else is bodged on the electrics. 

adonis

The old light would most likely be 240v mains, I would suggest getting an electrician in to do it if you are not sure.

Cornucopia

Those cables are ancient - the color scheme before the last one.   Google says pre-1977.  You might want to get a professional opinion on whether re-wiring would be recommended.

As always, mains voltages are dangerous, and it's bad idea to work with wiring unless you know what you are doing.

It will (probably) be the two black wires you need, unless your new fitting has metal parts and requires an Earth connection (that will be the green).

I assume where you say "normal 12v" that's a typo.   This is of course 240v mains wiring.   If your LED unit needs 12v, then you need a transformer, too.

binft

Cornucopia said:

Those cables are ancient - the color scheme before the last one.   Google says pre-1977.  You might want to get a professional opinion on whether re-wiring would be recommended.

As always, mains voltages are dangerous, and it's bad idea to work with wiring unless you know what you are doing.

It will (probably) be the two black wires you need, unless your new fitting has metal parts and requires an Earth connection (that will be the green).

I assume where you say "normal 12v" that's a typo.   This is of course 240v mains wiring.   If your LED unit needs 12v, then you need a transformer, too.

Pre 1977 would make sense as my flat is a 1970s build. Yeah I mean 240v or whatever it is I always say 12v cause I normally fiddle about with the car electrics. New led lamp is straight positive/negative connection no other cables so that's why I thought it would be a straight swap as they are indicated to be this kind of swap when you read the description on them.

grumbler

binft said:

Cornucopia said:

Those cables are ancient - the color scheme before the last one.   Google says pre-1977.  You might want to get a professional opinion on whether re-wiring would be recommended.

As always, mains voltages are dangerous, and it's bad idea to work with wiring unless you know what you are doing.

It will (probably) be the two black wires you need, unless your new fitting has metal parts and requires an Earth connection (that will be the green).

I assume where you say "normal 12v" that's a typo.   This is of course 240v mains wiring.   If your LED unit needs 12v, then you need a transformer, too.

  New led lamp is straight positive/negative connection no other cables so that's why I thought it would be a straight swap as they are indicated to be this kind of swap when you read the description on them.

Positive/negative indicates 12V - if this really is the case. Hard to believe. Can you post a photo or a link?

binft

grumbler said:

binft said:

Cornucopia said:

Those cables are ancient - the color scheme before the last one.   Google says pre-1977.  You might want to get a professional opinion on whether re-wiring would be recommended.

As always, mains voltages are dangerous, and it's bad idea to work with wiring unless you know what you are doing.

It will (probably) be the two black wires you need, unless your new fitting has metal parts and requires an Earth connection (that will be the green).

I assume where you say "normal 12v" that's a typo.   This is of course 240v mains wiring.   If your LED unit needs 12v, then you need a transformer, too.

  New led lamp is straight positive/negative connection no other cables so that's why I thought it would be a straight swap as they are indicated to be this kind of swap when you read the description on them.

Positive/negative indicates 12V - if this really is the case. Hard to believe. Can you post a photo or a link?

see below





and this is the old light connection that had the two black cables in it 

EssexExile

The two wires that went to the old light go to the new light. It's 240 volts so be careful.

binft

EssexExile said:

The two wires that went to the old light go to the new light. It's 240 volts so be careful.

Yeah my plan was to check which is pos and neg with the multimeter, then turn off electrics, wire up and turn back on to see, just never seen them as double black before usually red/black but that's probably not the norm for house wiring.

Section62

binft said:

Pre 1977 would make sense as my flat is a 1970s build.

It looks like the wires are coming out of a metal conduit box, so you might have a metal conduit system. (Is the ceiling concrete?)

So I would be a +1 for getting a professional to check the system over if it hasn't been done for a while.

Meanwhile, when you are putting everything back together, make extra sure none of the wires get chaffed, nicked or trapped on the metal parts of the box.

FaceHead

You really need to get some batteries for your multimeter, so that you can test what's going on and get it right. Otherwise you may end up toasting your new lights, or yourself. 

Getting a shock of 230V is a different kettle of fish to 12V