Hanging lights

[Albert]

Went to see a customer. They have the kind of lights that supplied by transformer. The live and neutral wires are pulled across the room and the light fittings connected with screws to the wires (the screws make the contact with the wires going through the insulation).

this system has a repeated problem that is a spark between the connections of the light fitting and the wires as well as between the connections of the wires coming from the transformer and the wires that the lights hanging from. This is an existing installation, as the wires are damaged (burnt) in several places I decided to change the wires (the customer does not wish to install a different type of lighting).

I assume that the spark caused by a gap created between the connection screw and the wires.

As I would not like to change the wires and have the same problem, does some one have ideas how to eliminate or at least minimize this problem?

 

[Steve]

Replace the wires and tell Ikea to stop selling such tat while you're there?

I take it the screws pierce the insulation? In which case I cant think why they'd be arcing.

 

[hairyben]

In short, make sure all the connections are tight.

That said wire track is a pretty half a5sed setup at the best of times. An office I frequent has about 70 or so lights on a dozen or so tracks. I've replaced every lamp fitting and replaced half the cabling. And this is the "commercial" version.

 

[Albert]

I take it the screws pierce the insulation? In which case I cant think why they'd be arcing.

I Think that in time a gap is created between the edge of the screw and the wire (under the insulation) in the connection point. I think that it is the same as with other electrical connection made with screws, I found many times that light switch connections or sockets are almost free, I am sure that they were done properly when the work was carried out.

 

[333rocky333]

some of these work like the old festoon lampholders with a pointed bit going into a stranded cable,and as you say the connection breaks down.
You sometimes find the screw is a steel grub screw which don't help.

sometimes removing the screw and cleaning the end up helps

 

[Albert]

A single round cable with transparent insulation, external diameter between 4.5mm and 4.9mm (need to be fitted in a 5mm diameter hole as in the attached photos.

It seems that the cable is reinforced (internally) to carry its weight plus the light fittings.

Tried several wholesalers and the internet no luck. Any one with a supplier? Otherwise it means the change all the system.

Untitled

• Albert
• 26 Feb 2009
• 1

Untitled

• Albert
• 26 Feb 2009
• 1

 

[electronicsuk]

How much do you need? I have some left over from a job, although I haven't measured it.

 

[Albert]

How much do you need? I have some left over from a job, although I haven't measured it.

I need 2 setts of lengths, one is 2x 6m (6m for L and 6m for N). than there is a very long one in the bathroom, a connection that goes in diagonal and hooked in 4 sides (diamond shape) I think that for this one I will need about 2x 13m.

In total for a perfect solution I will need 38m, but as I detailed, any part that is not shorter than 6m or 13m will be good.

Obviously you know that the cable must be the correct type and size.

If you have any! of this please let me know, if yes we can communicate via e-mail or by phone.

 

[electronicsuk]

I'll measure up tomorrow for you, but I know for sure that I don't have anywhere near 36 metres of the stuff!

 

[Albert]

I'll measure up tomorrow for you, but I know for sure that I don't have anywhere near 36 metres of the stuff!

Don't worry, if this the right stuff (the internal reinforcing wire is important) I need 2 bits of 6m or 2 bits of 13m or 19m or 25m in one piece etc. If you have any of these combination send it and I'll cut it as necessary. Or just tell me what you have and I will decide how it will work out for me.

If you know where I can get this cable It would be helpful if you pass me the details, as I said I will take from you what you have (assuming this is the right cable), and if I need more or for the future I will use the supplier.

 

[electronicsuk]

OK, so measured up (ooh er) and I have 8 metres, external diameter is in the area of 4.5mm. It came as part of a kit, so I don't have a supplier for just the cable alone.

Also, there is no internal 'reinforcing' wire as you describe - it looks extremely similar to what you have, but it's simply translucent plastic coated stranded steel wire. All the conductor material is exactly the same throughout, but from your description I get the impression that your cable has a steel reinforcing core surrounded by stranded conductors.

Here's a picture, if it helps: View media item 8997

EDIT: Wasting my time. Just come across a supplier for you: http://www.lightingstyles.co.uk/Low_voltage_wire_systems.htm

Nontheless, if you do still want the cable then you're welcome to it for the cost of postage.

 

[Albert]

electronicsuk Many thanks for spending the time and effort to help out. Just one remark, I looked again and it seems that the reinforcement is not a steel wire, what you can see is 2 different stranded wires, a small one that is surrounded by a larger stranded wire.

For what is worth, yes if you do not mind send it to me and tell me how much I need to pay, e-mail me to [email protected] with the detail (how much and where to send the cheque), I will reply with my details so you can send it to me.

Again many thanks
Albert

 

[Albert]

electronicsuk Many many thanks, I received the cable and it is too small, I measured it and it is about 3.7mm. it was a good try and much appreciated.

If you need the cable please let me know, if so send me your address and i'll send it back to you.

Posing charges on me...

 

[electronicsuk]

Worth a try eh? Keep the cable, I have no use for it so not a lot of sense in posting it back.

 

[Albert]

Worth a try eh? Keep the cable, I have no use for it so not a lot of sense in posting it back.

Thanks