2.5mm² for a lighting circuit? (And why not in a ring??)

Hello again Holmslaw...
...and thank you for your constructive response.

Bed 1, you do not need fused spurs for your wall light, suggest you loop in at switch.
The wife likes these plug-in LED box-lamp things that we got [I think] from Ikea. They have a 12V power supply plug, and the jack plug conveniently fits down the 20mm oval conduit and into a pattress box which is covered by the lamp. It's a means to hiding the wire in the wall and making it look tidy in the bedroom.

Lounge, suggest you loop in at switch...
...Any where you have TBD you should loop into switch.
Aww, do I have to??!! :cry:
Some of these are 3-gang switches, and one of the hall lights shares the same conduit drop for the lounge switch.

You should add the switch positions.
Gimme a few more hours!

Kitchen, you might find it easier to wire the plinth and under cupboard lights from the kitchen power via fused switched spurs.
Hmm, I can see that working for the plinth lights. I'll get back to you on the under cupboard ones.

Bath, whats the spur for?
They might be downlighters, they might be two fluorescent luminaires, or it could be one single light in the middle.
The fan might be one of those with a light in the middle, so again we don't know exactly where it's going yet.
Ask my wife once we've fitted the porcelain!

Bath, do you need a shaver socket? If so take it off the lighting circuit.
Yes, and if nothing else for future-proofing the bathroom when we sell-up in a few years!
By "take it off" the lighting circuit, you mean take it OUT and run a fused spur off the mains? Can you loop-in/out of a shaver socket instead of using a JB?

I take the light positions as being indicative ie not the actual position.
They're reasonably indicative, certainly more-so than the first diagram I did.
The wife and I spent a good part of the weekend deciding where the fittings should go, at least for the lights we're reasonably sure about.

The JBs for the unknown lights are all in a line because that was part of my original plan to locate them along a common "busbar", so to speak. Looking at the final positions for the light fittings I suppose they're not too far adrift from these common lines, so the loop-in loop-out isn't as onerous as I thought it was going to be.

I am not going to ask what size of cable. :)
I can guarantee it is the same thickness throughout! ;)
 
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holmslaw said:
I take the light positions as being indicative ie not the actual position....
...Your lighting layout should be uniform, if there's one light on the ceiling it should be in the centre - otherwise it can look cak.
Ah, I see where you're coming from. In that case, no, the diagram is still suffering from a case of Tubemapitis. There's an update below.

holmslaw said:
[Bedroom wall lights,] how you going to switch them?
I think my original diagram with the JBs was closer to the mark, but on reflection I can see how a loop-in at the switch might be beneficial here, especially as the switches are singles. When these LED light boxes break down, or fall out of favour with the wife, a more conventional uplighter can be fitted and the FCUs and sockets can be removed from the circuit - no-one need ever know they were there!

You'll also note on the new diagram the 3A socket for the CCTV has been deleted - I'll spur this off the mains instead.


holmslaw said:
You obviously intend fitting a "fancy" luminaire, I've never seen one designed to take loop in cables, so its easier to loop at the switch. You can get double boxes that are 50mm deep - plenty of room.
I really don't want to do that! :cry:
As you can see the kitchen switches are already quite busy, and I daren't go any deeper with the boxes and chasing. I'll look at the box near the hall door again, but I don't like my chances.

holmslaw said:
[Shaver socket] ...you need the isolating transformer type that fits in a 50mm deep box mounted vertically.
Yep, got all that and everything in place, just need to loop in at the socket now, as per the new diagram below.

holmslaw said:
Do you want two way switching in the hallway?
Yes, I have that planned, and I'm happy to loop-in at the roses with the "cable saving method" (I bet that's going to go down well!)


On a final note, you can see I've taken your advice about the LED plinth lights coming off the mains, as there's an old pattress and chase near to the floor that I can re-use. My only concern is that the transformer is going to be constantly energised, still adding it's little contribution to the climate change even when the lights are off. Am I missing a trick here?

Thanks again

(BTW, the thin lines on the diagram don't mean I'm using thinner cable. It's just to distinguish the loops from the spurs!)
eblight-20080529.PNG
 
To OP.
You need to buy the IEE OnSiteGuide AND a good Electricians Guide.
- Problem is not what you know, but that you do NOT know what you NEED to know.
- You must ensure all work complies with BS7671 IEE Wiring Regulations, including best practice, right materials etc.


Domestic lighting...
1. Lighting should be wired via a LOOP-IN method.

2. Regulations require screw-terminal junctions remain ACCESSIBLE.
- Ceiling-Rose provides 1) junction box 2) accessibility
- Cheap, simple, very rapid i&t (inspection and testing)

3. Labelling is REQUIRED re Supply-In, Sw, Supply-Out.


Rarely the ceiling rose method is inappropriate.
- Access difficult - "arty house", 30ft ceiling, scaffolding access
- Listed house - period chandeliers without ceiling rose alongside
- Continual alteration - offices with rapid-change stud walling

Hence Jn-Boxes are permitted IF they remain accessible.
- Only place in domestic is all under a hatch on landing floorboards
- Impossible to place furniture over that area
- Possible to fit laminated floor, MUST have access panel in laminate

Jn-Boxes are reserved for huge houses, offices, or complex automation systems.
In such instances the jn-box is actually replaced by large box & commoned DIN rail terminals. Very fast i&t compared to chasing 100+ ceiling roses, easy X10 additions, easy extensions or changes, easy to dymo label & provide a schematic in the lid.

Hope that explains why standard is loop-in via ceiling roses. Keep things simple.


Avoid 1960s faux pas.
- No junction boxes in the middle of a floor above chandelier
- This is not accessible re under 1/2-ton bed, fitted wardrobe, laminate floor

Do consider basic upgrades.
- Interlinked smoke alarms, preferably mains with battery backup
- Heat alarm in kitchen, smoke alarms elsewhere
- Read where & where NOT to install them re dead spaces

AICO are a good make, reasonable wiring space, well regarded.
 
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I notice from your diagram you show central ceiling roses in bedrooms.

Generally one tries to fit ceiling roses by the window, that is to replicate external lighting and to avoid undesireable shadows. If you put a light in the centre and someone walks naked across the window, their naked body outline is silhouetted. If the light is by the window they are not backlit.

Similarly beware spotlights over beds, fine until you lay back in bed and are promptly dazzled by the lights.

Some brilliantly bad new houses out there :)
 
Generally one tries to fit ceiling roses by the window, that is to replicate external lighting and to avoid undesireable shadows. If you put a light in the centre and someone walks naked across the window, their naked body outline is silhouetted. If the light is by the window they are not backlit.

Thats a very old fashioned way of doing things these days...
 
"2 way cable saving method"... WTF? :) :)

ARGH.

OP...
1. BUY 6243Y 3Core+Earth from www.tlc-direct.co.uk BY THE METRE.
2. Sleeve lighting tails correctly.
3. BUY a proper book - Whitfields Guide For Electricians & Executioners still around?

If you are still unsure, draw out what you want, get a spark to check it & specify cable/roses/whatever, you do the donkey work feeding cables around, they come along to connect, R1+R2, IR, EFLI, check your MEB, check RCD provision since a rewire. Test gear to BS7671 is £550 with calibration certs and even a serious DIYer should own one. Car tinkerers likewise have to buy OBDII/III scanners/adapters, laptops, toolsets, quite specialised expensive tools (BFH) so it goes with the turf.

BS7671 17th places a new requirement "A person who possesses sufficient technical knowledge and experience for the nature of the electrical work undertaken and is able at all times to prevent danger,
and where appropriate, injury to themselves and others."

Plenty of DIYers have this, C.Eng. with C&G 2391 (2392 in Aug), whereas a great many do not. OP needs to understand his limits, that is not patronising, but correctable a) by assistance b) by reading a good book. You actually need to know why you are doing certain things, and not just how - it helps with the overall quality of the installation and seemingly minor safety points which are expensive to fix later on.


Golden rule - leave it better than you found it.
Now why is it plumbers, kitchen fitters, developers and government never do that... .... what's that sound... sounds just like a tomah... OFFLINE.
 
jason1958 said:
I notice from your diagram you show central ceiling roses in bedrooms.

Generally one tries to fit ceiling roses by the window, that is to replicate external lighting and to avoid undesireable shadows. If you put a light in the centre and someone walks naked across the window, their naked body outline is silhouetted.

I've got to deter the burglars somehow!

Actually Bed 1, Bed 3 and the Lounge will have a central ceiling fan. These rooms are at the back, and we have no houses behind us until the farmer sells his field to developers! Bed 2 has no fan, and we may still move the light slightly closer to the window.

holmslaw said:
... your latest post raises more concerns. 2 way cable saving method...is absolutely totally unsuitable for what you are trying to achieve.

Please do not attempt to do this wiring you will end up in a complete mess.
I wondered if that 'saving' technique would find favour or not!

Holmslaw,
as perhaps my most ardent critic, your comments are the most appreciated. Your concerns on my competence are noted, and aside from the two-way switching technique, and my intention [you could call it insistence!] to use JBs, what else concerns you about the layout? I thought by now the layout was pretty much a standard loop-in at the rose affair?

jason1958 said:
...Jn-Boxes are permitted IF they remain accessible.

Jason1958,
I can assure you that any junction boxes I fit will be quite accessible, which prompted a large part of the criticism I've (perhaps rightly) received.
Thanks for the rest of your advice and comments - some points have hit the nail on exactly what I'm trying to acheive, especially with regards to the scope of my limitations - I'll elaborate on that later on.

In the meantime I need to get back to work at what I do best... how else do you expect me to pay for an electrician!

Catch you all later, and thanks again.
 
holmslaw said:
What happened to the spur for the cctv camera?
On 29 May 5:44pm edenbridge said:
You'll also note on the new diagram the 3A socket for the CCTV has been deleted - I'll spur this off the mains instead.

holmslaw said:
Why is the cctv camera controlled from the 4g switch in the hall, surely you want the camera on continuously.
The fourth switch is an override for the PIR light in the driveway.

holmslaw said:
The wc does not need a pull cord.
Ah, you see, this is where I've been told different!
There's going to be a basin on the wall opposite the door, and legend has it that if can you put one hand in a basin and touch a light switch with the other, it's a shock hazard.

Besides which, I forgot to chase that one out!

But my wife reminded me a pull cord is prefereable anyway for when my disabled father-in-law comes to visit, as he'll use the WC instead of the pan in bathroom.
 
Legend is wrong.

Switches are only not allowed in rooms containing a bath or shower. A WC has neither of these.

You are free to fit a pull switch if you like though.
 
> Switches are only not allowed in rooms containing a bath or shower

Switches are.

The wiring accessory must be suitable for the Zone requirements defined in BS7671.
- In Zone 2 - needs IPx4 (masterseal, clipsal weatherproof)
- In Zone 3 / Outside Zone 2 - conventional switch ok

The designer may decide that the likely usage requires stricter interpretation (I think NICEIC also use a 60cm semi-circle above wash basins, probably to stop hair dryer outlets which are common in Germany & France).
 
suggestions..

1. 2 way switching of the master light in the bedrooms..
2. are the hallway lights to be switched independent of each other? if not then you don't need to loop the mains into both..
3. wire the bathroom off either a fused spur from the ring main (if it's RCD protected ) , or a seperate breaker on the RCD side of the board / RCBO..
4. extra hall light switch by the master bedroom, it's a long way to the nearest other switch in the night. ( or possibly a 360 PIR sensor / timer so that it will pick up anyone entering the hall.. )
 
Hello again everybody!

Sorry to disappoint, but my absence from the forum WASN'T the result of a dodgy lighting circuit - I've had a few other issues to deal with instead.

Since buying this new property we've learned that it was originally built by a well-known local businessman with a bit of a 'reputation'. He obviously hired the cast of Rawhide to build the house, and this is part of the reason why I'm reluctant to do any more chasing to facilitate the "loop-in at the switch" technique.

This will probably be my last post on this thread, so in response to some of your comments and suggestions:

holmslaw said:
I suggest you draw out exactly what you want and contact a local spark ...
jason1958 said:
...draw out what you want, get a spark to check it... you do the donkey work feeding cables around, they come along to connect...
At the risk of angering many of you, but hopefully to your relief, this is exactly what I've been doing all along.

As a designer/engineer, I'm afraid it's in my nature to play devil's advocate and get a second opinion. I respect my electrician's advice, but he'll tend to go along with whatever I have in mind, so long as it doesn't contravene any regulations.
I was mainly using this forum as a design review, or even a brainstorming session to see if I've considered everything. Please don't feel I've wasted your time, I just like to bottom things out.

With all your useful advice and suggestions, I've gone back to my electrician and made a few changes to the design, and he'll be happy to sign it off when it's done. There may still be a few more junction boxes than most of you would like, but one thing is for certain:
jason1958 said:
Golden rule - leave it better than you found it.
It appears that the local businessman sold his house to Ben Cartwright and his family, so making a better job of the electrics isn't difficult!

jason1958 said:
the OP needs to understand his limits
I do, and that's why I won't be making any of the connections!

As I always tell my colleagues: "A good draughtsman knows where to draw the line." 8)

Thanks again, and goodnight.
 

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