Fitting cable for an illuminated mirror

[AndersonC]

As I sort out the bathroom walls prior to tiling I need to install a cable to supply an illuminated mirror.

In order to allow me to position the cable correctly (I am not going to be connecting it up just positioning it behind plasterboards), where will it need to take it's supply from? The lighting circuit, possibly wired into the ceiling rose, or another circuit with greater current carrying capacity?

The kind of mirror I am considering will have a couple of low wattage lights fitted in it, for example:-

which has 2 18 watt lights in it.

Any guidance appreciated, thanks

 

[plugwash]

Most likely the lighting circuit but it would be good to know what lighting is on that circuit already so we can tell if there is enough spare capacity.

Also to comply with the 17th edition it will need to be RCD protected somehow (most likely with a RCD FCU)

 

[AndersonC]

Hello

All the electrics in the house are protected by RCDs as the house was fully rewired in Nov 05.

As regards the upstairs lighting circuit, the total load on this at the moment comprises 5 light fittings which consist of:-

1 100W low enegery bulb
1 100 standard bulb
1 ceiling fan/light with 3 60W bulbs in it
1 spotlight assembly with 4 50W bulbs in it
1 bathroom light with a "fluorescent ring" bulb in it about 10" diameter

The existing plan is also to replace this pretty useless bathroom light with IP44/IP65 downlighters, with 4 lights of 35W bulbs.

Hope this information is helpful

Anderson

 

[ban-all-sheds]

All the electrics in the house are protected by RCDs as the house was fully rewired in Nov 05.

It would be very surprising if they are all on a 32mA RCD. Do you have a TT supply with a 100mA RCD as the main switch?

The existing plan is also to replace this pretty useless bathroom light with even more useless IP44/IP65 downlighters, with 4 lights of 35W bulbs, costing more to run and providing less light.

 

[Chri5]

Most likely the lighting circuit but it would be good to know what lighting is on that circuit already so we can tell if there is enough spare capacity.

Also to comply with the 17th edition it will need to be RCD protected somehow (most likely with a RCD FCU)

Come on, there's very little chance that the average dwelling will ever over load a light circuit.

Circuit 6A is nearly 2000w thats 40 x GU10's, 33 x 60w bulbs or 95 x 21w LE lamps before diversity is considered.

It's always good to play safe, and some checking is always prudent- but is it really necessary to audit light circuits for use each time a light circuit has a 36w device added.

 

[plugwash]

Circuit 6A is nearly 2000w

1380 actually, hardly "nearly 2000"

and don't forget people sometimes put halogen security lights on lighting circuits, one of those and nearly half your capacity is gone, combine that with a heavy downlight install and you could easilly be overloading the lighting circuit.

As for applying diversity to lighting circuits I think it is a terrible idea, when the property is fully occupied there is a very high chance of every light being on at once.

 

[AndersonC]

All the electrics in the house are protected by RCDs as the house was fully rewired in Nov 05.

It would be very surprising if they are all on a 32mA RCD. Do you have a TT supply with a 100mA RCD as the main switch?

The existing plan is also to replace this pretty useless bathroom light with even more useless IP44/IP65 downlighters, with 4 lights of 35W bulbs, costing more to run and providing less light.

All this winking is confusing!! I don't give a flying toss about the cost to run the lights either, what's that got to do with anything? The previous light was fairly dull so it's going.

Anyway, being positive, I will check the RCD's in the CU and find out what they are spec'd at.

 

[AndersonC]

Circuit 6A is nearly 2000w

1380 actually, hardly "nearly 2000"

and don't forget people sometimes put halogen security lights on lighting circuits, one of those and nearly half your capacity is gone, combine that with a heavy downlight install and you could easilly be overloading the lighting circuit.

As for applying diversity to lighting circuits I think it is a terrible idea, when the property is fully occupied there is a very high chance of every light being on at once.

There will be no security light added to this circuit, it is the upstairs lights. The only room upstairs which will have downlights is the bathroom.

The only people occupying the house are me full time and the missus part time.

Based on the above and the previous comments, it seems I don't have a problem. If there is what difference would low voltage lighting with a transformer make? (to the circuitry not the running cost )

 

[ban-all-sheds]

I don't give a flying toss about the cost to run the lights either, what's that got to do with anything?

It just seems to be verging on madness to replace a lighting solution that doesn't work very well with one that will be even worse and will cost more to run both in terms of electricity consumption and lamp replacements.

If there is what difference would low voltage lighting with a transformer make? (to the circuitry not the running cost )

None whatsoever - 140W is 140W.

 

[AndersonC]

Yes I see your point but the downlighters I have seen look bright, modern and stylish. I haven't seen any other style of light which would suit the style I have in mind.

Thanks for the clarification over the low voltage lights, I guess these must run at a higher current then to deliver the same power from a lower voltage, withthe transformer performing the task of reducing voltage and upping current.

 

[ban-all-sheds]

http://www.exclusivelighting.co.uk/acatalog/Ceiling_Lights.html

http://www.lightingstyles.co.uk/Ceiling.htm

http://www.ascolights.co.uk/ceiling_lights.html

http://www.scossa.co.uk/acatalog/Wall.html

http://www.scossa.co.uk/acatalog/Ceiling_Fittings.html

http://www.directlight.co.uk/modern_flush_ceiling_lights

http://www.directlight.co.uk/contemporary_semi_flush_ceiling_lights


http://www.lightingdirectory.com/


http://www.lightingdirectory.com/sub-cats/id/1/architectural-lighting

http://www.lightingdirectory.com/sub-cats/id/71/distributors-and-wholesalers

http://www.lightingdirectory.com/sub-cats/id/82/energy-saving-lighting

http://www.lightingdirectory.com/sub-cats/id/65/fluorescent-lighting

http://www.lightingdirectory.com/sub-cats/id/8/home-lighting

http://www.lightingdirectory.com/sub-cats/id/11/hotels-and-leisure-lighting

http://www.lightingdirectory.com/sub-cats/id/69/lighting-retailers

 

[skenk]

If there is what difference would low voltage lighting with a transformer make? (to the circuitry not the running cost )

None whatsoever - 140W is 140W.

Does it not take more than 140w of energy to light 140w worth of ELV halogens? . . . what about the heat lost through the transformer?

 

[AndersonC]

BAS - thanks for the links, I will have a look but hope the missus doesn't 'spot' them, else I'll be here all night!!!