Mains or lighting ring?? ?

[Stevie_nw]

Hello,

May sound like a really stupid question, but is it better to install an external halogen security light (built in PIR) though the lighting ring or the mains ring??

The light is the usual kind you buy from most DIY superstores(no I\\\'m not going to plug them, they get enough trade)

I\\\'m comfortable patching into either of these rings. Hope someone is good enough to reply(after they have finished laughing)

Cheers

Steve
_______________________

Moderator

moved as posted wrong forum (general diy)

[basic]

what size is the light fitting
i.e. 20watts, etc

then total the number of lights on yopur lighting circuit for the area you wish to install.
i.e if outside kitchen wall, whats the number of lights/ downlights on that room and is it on its own circuit?

Post back the info
________________
moderator

basic. please note 10 a

[Stevie_nw]

I will be running it from the downstairs ring, there are a total of 6 lights all interior on the downstairs ring. The light I'm fitting is 150W tungsten halogen, and it will only be a single external light that I will be fitting onto which ring(light or mains)

Lamp Type
Linear Tungsten Halogen
Cap: R7S
Lamp Wattage: MAX 150w

Hope this is some help, it means less than nothing to me.

Thank you again for all your help.

Steve

[DyslexicGrimsbySparkie]

The lighting circuit is not usually a ring. it usually terminates at the last ceiling rose or junction box.

Usually the lighting circuit is protected by a 6A MCB so that equates to about 1380W (although you should take some off that for losses)

Provided you do not exceed the rated output for the circuit you would be okay wiring the outside light on the lighting circut. By the sounds of it unless you have multiple lights on each fitting you are only consuming around 600w (assuming you've got 6x 100W bulbs)

I would personally install all exterior lighting on a seperate circuit from the CU but that is sometimes easier said than done.

----------------------
edited typo fo 6A

[Qedelec]

5Amp MCB never seen one of those.
Personally I would run the outside light off a Switched Fused Connection Unit to comply with regs. Any item of current using equipment must be able to be isolated locally for maintenance, the MCB is not adequate for that purpose.

As an aside, Has anyone seen a 10amp 1362, found one fitted to a fridge 1363 plug.

[Stevie_nw]

Cheers for the reply, will get my rubber boots on, and have it done this morning.

Buzzin'

[ban-all-sheds]

Qedelec wrote:

As an aside, Has anyone seen a 10amp 1362, found one fitted to a fridge 1363 plug.

From BS 1362:1973 Incorporating Amendment Nos. 1 and 2
Specification for General purpose fuse links for domestic and similar purposes (primarily for use in plugs):

5.3.2 Rated current of the fuse link. The rated
current may be any value not exceeding 13 A. For
use in plugs, the preferred rated currents are 3 A
and 13 A.

OOI, the standard only specifies requirements for time/current curves for 3A and 13A.

[plugwash]

you can get plug fuses in 1A 2A 3A 5A 7A 10A and 13A from the likes of RS and FARNELL

i have personally seen 2A 3A 5A 10A and 13A

[Adam_151]

Qedelec wrote:

5Amp MCB never seen one of those.

I have, actually got a plug in one in the garage wylex cu, i've seen din ones as well, the cu in my late grandmother's house was a 'modern' din rail style unit, yet still quite a few years old and that had a 5A type 1 MCB, as well as some 30A ones (as opposed to 32A)[/quote]

Quote:

As an aside, Has anyone seen a 10amp 1362, found one fitted to a fridge 1363 plug.

Yup, seen them in suppliers catalogues, as well as fitted to the secondary circuits on a rather large SELV lighting transformer thats hanging around in the garage somewhere, shouldn't IEC320 power cords be fused with these?

[thatstarinthesky1]

i know this is an old thread but its relevant for my question.

I am having my house re-wired and just wanted to check what the pros and cons of having a seprate circuit for extrenal lighting were?

I am planning to install two external floodlights (potentially with motion sensors).

My second question is what are the pros and cons (if its even possible) of using low energy external lighting?

I want to keep the cost down and dont expect the lighting to be used too often, but would like it to have good brightness when it is used.

[PrenticeBoyofDerry]

There are a number of pros concerning having a separate circuit for outside lights. Mainly to do with nuisance trips of RCDs, ease of isolation and faulty finding.
Cons: Extra way in consumer unit, possibly more routing of cables and extra material and labour cost.,
Low energy lamps can be used, they sometimes take a little time to get to full brightness but no real major issues.

[thatstarinthesky1]

PrenticeBoyofDerry wrote:

There are a number of pros concerning having a separate circuit for outside lights. Mainly to do with nuisance trips of RCDs, ease of isolation and faulty finding. Cons: Extra way in consumer unit, possibly more routing of cables and extra material and labour cost., Low energy lamps can be used, they sometimes take a little time to get to full brightness but no real major issues.

Thanks.

1) I had heard it was "bad wiring" (and were not allowed) to link to internal lights, but sounds like its more convenience related.

Sounds like its better to have it separate in any case.

2) Is the delay the same as with with the internal CFL lights?

Whilst slightly annoying it hasnt been enought to put me off CFLs though.

Also what wattage CFL bulb would be equivalent to say a 300W Halogen?

[PrenticeBoyofDerry]

I assume we are talking of the same lamp low energy/CFL so same delay.
Watt valuves for CLF to conventional incandescent lighting would be about 55W to equal 300W, halogens produce about 50% more light per watt than incandescent lamps.

thatstarinthesky1 wrote:

1) I had heard it was "bad wiring" (and were not allowed) to link to internal lights, but sounds like its more convenience related.

I don't think there are any requirement stating this can not be done.
But issues regarding environment nuisance trips would be a concern.

[davelx]

PrenticeBoyofDerry wrote:

I assume we are talking of the same lamp low energy/CFL so same delay.

Except that in winter they will get much colder being outdoors and therefore take rather longer to reach full output.

[riveralt]

thatstarinthesky1 wrote:

I am having my house re-wired and just wanted to check what the pros and cons of having a seprate circuit for extrenal lighting were? I am planning to install two external floodlights (potentially with motion sensors).

You will have to be guided by the manufacturers instructions but most seem to want some means of isolation built into the circuit anyway usually via a switched 3Amp Dual Pole Fused Connection Unit. An additional benefit of this is the ability to 'double click' the switch to keep the light on permanently.
IMO you do not need to go to the additional expense of fitting them to a separate lighting circuit - Unless the quantity and therefore the power of the said lights exceeds the capacity of the circuit. Properly fitted IP rated kit should not cause the RCD to trip anyway and if it does cause problems you have a ready means of isolating the lamp from the rest of circuit.