Which wire and connectors ?

[JohnW2]

Here is the transformer and distributer

Ah, I see! The 'transformer' is, indeed, rated at 10-20W at 12V (as has been said, not enough for you). the 30V and 10A are merely the maximum ratings of the 'distributor' (basically just a junction box).

Kind Regards, John

 

[FerritVIP]

Yes only for 12v not the mains that's already sorted would this be the kind of transformer I need ?

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• FerritVIP
• 24 Aug 2014
• 1

With his wire ?

Untitled

• FerritVIP
• 24 Aug 2014
• 1

 

[Belboz]

Here is the transformer and distributer

Ah, I see! The 'transformer' is, indeed, rated at 10-20W at 12V (as has been said, not enough for you). the 30V and 10A are merely the maximum ratings of the 'distributor' (basically just a junction box).

Kind Regards, John

A picture paints a thousand words John.................

 

[JohnW2]

A picture paints a thousand words John.................

Quite so. We didn't even know that there was a 'distributor' (with voltage and current ratings) until a picture of it popped up - I don't think I can blame myself for having been confused

Kind Regards, John

 

[Belboz]

Yep - I was confused too. Hence asking for a pic.

Easy once the dog had seen the rabbit...........

 

[FerritVIP]

Are the pics of the wire and transform what I need ?

 

[Spark123]

The 60w transformer looks to be one that needs to be in an enclosure of some nature. You can get them which don't need an external enclosure such as here: http://www.tlc-direct.co.uk/Products/TLET60.html
As for the cable, mains two core cable (min 0.75mm) will do. I wouldn't bother with car wire.
As another option, you may use the transformer you have to run two lights and buy another one to run the other two.

 

[flameport]

Transformer: http://www.screwfix.com/p/robus-electronic-transformer-20-70va/97554
Cable: http://www.screwfix.com/p/flat-flexible-cable-2192y-2-core-0-75mm-x-5m-black/78613
Connectors: http://www.screwfix.com/p/5a-terminal-strips-pack-of-10/60804
Box: http://www.screwfix.com/p/chocbox/54936

Don't buy transformers or other electrical items from ebay.

 

[ban-all-sheds]

For a couple of metres of 5 amp cable the voltage drop can be ignored.

Only if you want to ignore the 3% voltage drop "limit", or if he's star-wiring them.

Automotive cable sold as "5A" will be 0.65mm², which drops about 71mV/A/m.

If the OP is star-wiring his 10W lights, then 6m will be OK for a 360mV drop.

But if he's daisy-chaining 4 of them, then "a couple of m" gets him to the first lamp, and no further.

 

[JohnW2]

Only if you want to ignore the 3% voltage drop "limit" ....

Methinks therein lies a can of worms The 'voltage drop 'limit " to which you refer (per 6.4 of 'informative' Appendix 4 of the regs) is to be measured from 'the origin of the installation' and is expressed as a percentage of 'the nominal voltage of the installation' (aka 230V)

Kind Regards, John

 

[ban-all-sheds]

It's a percent.

You can apply a % to anything. It may or not make sense to use 3% as the limit for an ELV lighting circuit - I don't know, which is why I put the word in quotes. (That's the problem with persistently misusing quotes - you forget what they actually signify.)

But if you don't ignore that 3% it can get eaten up quite quickly with incandescent ELV lighting.

 

[JohnW2]

It's a percent. You can apply a % to anything.

As a generalisation, indeed one can. However, I thought you were referring to Appendix 4 of the regs, and 6.4 thereof indicates that the 3% figure referred to in Table 4Ab means "3% of the nominal voltage of the installation" (i.e. 3% of 230V, aka 6.9V)!

It may or not make sense to use 3% as the limit for an ELV lighting circuit - I don't know, which is why I put the word in quotes. (That's the problem with persistently misusing quotes - you forget what they actually signify.)

I'm probably the world's greatest culprit as regards use of quotes! On this occasion, I thought you put 'limit' in quotes because it is essentially a recommendation in an 'informative' Appendix, rather than the 'regulation' which so many think it is!

As for what 'makes sense' or is appropriate for ELV lighting, it's fairly complicated. If we wish to remain consistent with the usual practice with LV lighting, I suppose that we should think in terms of the 'equivalent LV voltage drop' (** see below) expressed as a percentage of the nominal LV supply voltage - and, if we did that, I imagine that it would probably still be appropriate to apply the 3% 'limit'.
** I suppose the 'equivalent LV voltage drop' would be calculated as the actual VD in the LV wiring PLUS (the VD in the ELV wiring multiplied by the LV/ELV ratio of the transformer or PSU)

Kind Regards, John

 

[333rocky333]

most of them transformers limit the output length to the lamp at less than two metres,for EMC reasons, hence I assume one reason why the wickes fittings are prewired with plugs to allow the distribution box to star wire them