Radial Wiring

[pb1936]

Crossy or any informed member.............

.I am sorry that this is off topic but please can i ask you or someone what is meant by radial wiring. Basically I am trying to understand how the wiring is run from the consumer unit to individual lights and power points. Are the various elements connected in parallel and, if so, how many lights and/or power points can connected to one circuit ? I understand, of course, that there need to be different circuits for lighting and power.

I would much appreciate any comments.

[Forkinhades]

@ pb please start a new thread, and we will all be very glad to help

[Crossy]

I've split it out Forky

[Forkinhades]

^ ah thats a good cut and paste

[Crossy]

For outlets you run each in parallel, breaker to L to L to L etc, neutral bar to N to N to N, earth bar to E to E to E.

No theoretical limit to the number of outlets per circuit as the cable is protected by the breaker. Conventional wisdom is once circuit for the lounge, one to serve all the bedrooms and two for the kitchen where the watty devices live.

Many ways to wire lights, try a Google. I like to run a live and neutral to each switch box (means you can put a fan controller or similar device that needs a neutral) then daisy chain the neutral to each fitting to limit the number of wires in the dropper conduit. Obviously a switched live for each fitting from the switch box.

[Forkinhades]

@ pb

take a look at the pinned subjects

In answer to your questions. In Thailand the circuitry is mostly radials, but a good thai sparky will know how to do a 'ring' circuit, which would be a circuit that starts and finishes at the DB, and the cables connected to the same MCB, and corresponding neutral/earth terminals in the DB.

In Thailand mostly they (thai sparks) just take a cable into a room, and connect everything to that, lights and sockets. AC's and Heaters should have separate supplies.

Tell us what you are trying to do, and I am sure someone will design it for you

Note DB = Distribution Board

[citizen33]

@ pb

a good thai sparky will know how to do a 'ring' circuit, which would be a circuit that starts and finishes at the DB, and the cables connected to the same MCB, and corresponding neutral/earth terminals in the DB.

Note DB = Distribution Board

In a thread from long ago we had a discussion about radials vs rings. Crossy was of the opinion that rings might confuse a Thai repairman and were less suited to Thai conditions. I liked the redundancy built into the ground connection in a ring and also the fact that a ring might be better able to handle a higher current for a given gauge of cable. Crossy rightly pointed out that in Thailand, where plugs are not fused, you would need to use a lower amp MCB than would be the case in say the UK. I have never liked the idea of very long daisy-chained radials, with long multi outlet spurs, but this is permitted by the regulations.

I have had my sockets on two rings (upstairs and downstairs) for 10 years now with no problems. All my other circuits (water heaters, aircon, outside) are radials. The lighting is a kind of radial in tree configuration (again separate circuits for upstairs and downstairs). So I guess you can choose, though most opt for radials.

Edited May 2, 2013 by citizen33

[bankruatsteve]

Aagh - please do not promote your whacky ring circuits. There is absolutely no reason these days to use them.

[Forkinhades]

^ I have ring circuits installed here in LOS, and the 'thai' sparky knew what I wanted. I also have 'clipsal' sockets installed which can take any plug, mostly I use UK which are fused to MY liking.

I certainly would not call it whacky, and in certain circumtances they will work very well, especially if you are limited to the number of circuits you can install, without upgrading.

[Forkinhades]

Aagh - please do not promote your whacky ring circuits. There is absolutely no reason these days to use them.

Actually you was trying to something whacky with lighting circuits?

http://www.thaivisa.com/forum/topic/632858-join-two-separate-lighting-circuits-hmm/

EDIT : changed similar to whacky

Edited May 2, 2013 by Forkinhades

[citizen33]

I also have 'clipsal' sockets installed which can take any plug, mostly I use UK which are fused to MY liking.

Crossy will ask in a minute whether you have wired these so that the live is going to the fuse (the normal Thai socket has L and N the wrong way around for the UK plug).

I know I am in a minority with rings but when I built my Thai house I thought it was just as easy to design things so that the sockets fell in a big circle. Radials may be the sensible way but they look pretty ropey if a Thai electrician adds on lots of spurs to cover bits that were originally forgotten. Of course in my other home in the UK - and most other houses in my street - the ring rules.

Edited May 2, 2013 by citizen33

[Forkinhades]

I also have 'clipsal' sockets installed which can take any plug, mostly I use UK which are fused to MY liking.

Crossy will ask in a minute whether you have wired these so that the live is going to the fuse (the normal Thai socket has L and N the wrong way around for the UK plug).

I know I am in a minority with rings but when I built my Thai house I thought it was just as easy to design things so that the sockets fell in a big circle. Radials may be the sensible way but they look pretty ropey if a Thai electrician adds on lots of spurs to cover bits that were originally forgotten. Of course in my other home in the UK - and all the other houses in my street - the ring rules.

Fully tested by moi

[bankruatsteve]

Aagh - please do not promote your whacky ring circuits. There is absolutely no reason these days to use them.

Actually you was trying to something whacky with lighting circuits?

http://www.thaivisa.com/forum/topic/632858-join-two-separate-lighting-circuits-hmm/

EDIT : changed similar to whacky

OK - it was and if you go through the thread you will see I decided that myself.

Regarding ring circuits: you know (as I do after wondering what the hell they were some years ago) that they were "invented" to save copper during WW2. The concept needs diligent balancing and can have issues (as with spurs). Again, there is NO reason to use them these days and if you choose to - whatever - but please don't suggest that is a good way to do it just because it's done in Briton.

[Forkinhades]

(the normal Thai socket has L and N the wrong way around for the UK plug)

I dont have 'normal' Thai socket, I use clipsal (now schneider), which are clearly marked for the terminals for even the most laymen of people.

[Forkinhades]

Regarding ring circuits: you know (as I do after wondering what the
hell they were some years ago) that they were "invented" to save copper
during WW2. The concept needs diligent balancing and can have issues
(as with spurs). Again, there is NO reason to use them these days and
if you choose to - whatever - but please don't suggest that is a good
way to do it just because it's done in Briton.

when desiging a circuit would you take into consideration Volt Drop?

[bankruatsteve]

Regarding ring circuits: you know (as I do after wondering what the

hell they were some years ago) that they were "invented" to save copper

during WW2. The concept needs diligent balancing and can have issues

(as with spurs). Again, there is NO reason to use them these days and

if you choose to - whatever - but please don't suggest that is a good

way to do it just because it's done in Briton.

when desiging a circuit would you take into consideration Volt Drop?

For most domestic installations: NO.

[Forkinhades]

^ haha

no comment

[Crossy]

I would not recommend using rings in a normal Thai home (Forky's does not count, he's not a normal Thai). I do have some UK outlets, but they're on normal Thai radials and are purely for the convenience of guests.

I'm not going to get in to the rings-vs-radials discussion (visit the IET forums for that one), suffice it to say:-

• There's nothing whacky about a ring, they were conceived with a definite purpose in mind. However, that purpose is no longer really valid.
• Other countries that use the BS1363 (UK) plug (Malaysia, Singapore, Hongkong) use them on 4mm² (or 2.5mm² with a 20A breaker) radials or trees, rings are not permitted.
• There is discussion in the IET (IEE) that rings be removed/outlawed in the next version of BS7671 (some years off mind).
• The main argument against rings is that in the even of an open L or N the other leg is subject to potential serious overload as it places a 20A 2.5mm² cable on a 30A breaker and said fault does not manifest itself until the fire starts

Of course we're not in the UK anyway, the Thai regs make no mention of rings except for HV distribution where it's common practice.

If you put a Thai 16A unfused outlet on a ring with a 30A breaker you are potentially able to pull 40A plus from that outlet before the breaker thinks of opening, welcome conflagration, and if you fuse the circuit down to 20A to protect the outlets you negate the reason for having the ring.

Those 'universal' outlets are great for guests, but even ignoring the 'reversed' polarity I wouldn't trust one at 13A for any period due to the limited contact area allowed by the interestingly shaped contacts.

[Forkinhades]

Horses for courses.

Firstly I was only pointing the difference between the said 2 circuits, in a direct reply to the OP

At design stage for me 'rings' worked very well. I do not have any polarity issues, and mostly my portable equipment is fused at 3 amps. My media centre, kitchen appiances, Utlility appliances are controlled by Fused Connection Units @13 amps. Nothing portable can be plugged in to that part of the circuit.

The UK plugs are good for me, as I have a young child running about, who likes to put his little fingers in everything, the UK plug is designed in such a way where the terminals are insulated, and impossible for the child to touch. Can you say the same about some of the Thai plugs here. Some xmas tree lights come to mind.

Crossy is well travelled, and worked in a lot of countries, and of course has his opinion, and I will not be drawn into an argument as to what is better. You guys can do what suits you, I hope you indeed design your circuits accordingly, and realise how far you can go with a cable, and indeed take in the additional factor of ambient temperature.

[Crossy]

No argument Forky just noting some of the potential hazards of mixing and matching standards.

If you intend remaining in your home forever there is no issue whatever using UK standards and kit, they are indeed better in many ways than the local stuff although the new TIS166-2549 (2006) plug does address many of the safety issues with those horrible US style things.

http://www.crossy.co.uk/wiring/TIS166-2549.jpg

With no portable heating devices needed in Thailand (unlike the UK) the actual loading on any one circuit (apart from the kitchen) is rarely over 1kW if that.

If we are going to recommend a Western style set of wiring regulations I (even as a Brit) would suggest AS3000 as a good starting point, similar weather, similar layouts and similarly rated unfused plugtops.

[pb1936]

Many thanks to all........... brilliant !

So do I take it that the term " radial " refers to cables simply radiating from the CU to supply the fittings, rather than using a ring which returns to the CU ?

[Crossy]

Many thanks to all........... brilliant !

So do I take it that the term " radial " refers to cables simply radiating from the CU to supply the fittings, rather than using a ring which returns to the CU ?

Yup

Size the breaker to the smallest cable in your tree (should all be the same anyway) and you're good to go.

Outlet radials here conventionally use 2.5mm² twin with a 1.5mm² earth conductor on a 20A breaker (run two circuits to your kitchen) http://www.bangkokcable.com/catalog/BCC_CATALOG/VAFG2EN.HTML if you're running unprotected, or use similarly sized singles in conduit http://www.bangkokcable.com/catalog/BCC_CATALOG/THWEN.HTML.. Interestingly the Aussie regs require the earth to be the same size as the main conductors when you run singles, but reduced is OK if they're in a cable, no idea why.

For lighting run 1.5mm² (you could use 1mm² but I find it too small and fragile mechanically), whether you earth is up to you, use Class-2 fittings and you don't need it, protect with a 10A breaker.

Also note that the colour code used here is nominally the NEC (US) code, Black-live, White/Grey-neutral, Green-earth, although for some reason the outdoor flex http://www.bangkokcable.com/catalog/BCC_CATALOG/NYY3EN.HTML carried by Homepro is Black, White, Red.

[Forkinhades]

No argument Forky just noting some of the potential hazards of mixing and matching standards.

If you intend remaining in your home forever there is no issue whatever using UK standards and kit, they are indeed better in many ways than the local stuff although the new TIS166-2549 (2006) plug does address many of the safety issues with those horrible US style things.

http://www.crossy.co.uk/wiring/TIS166-2549.jpg

With no portable heating devices needed in Thailand (unlike the UK) the actual loading on any one circuit (apart from the kitchen) is rarely over 1kW if that.

If we are going to recommend a Western style set of wiring regulations I (even as a Brit) would suggest AS3000 as a good starting point, similar weather, similar layouts and similarly rated unfused plugtops.

Intend staying for a long time. Having said that, can easily change back accessories if needed.

Good plug, which of course my accessories can accomodate.

Pleased to help pb

My calcs were done with ambient temperature @ 32 C, and I only use type 'B' MCBs. Mostly here in LOS they are 'C'

[bankruatsteve]

Regarding my reference to ring circuits as "whacky"...

According to Merriam-Webster online dictionary (I find the spelling should be) wacky is defined as: different from the ordinary in a way that causes curiosity or suspicion.

And, from an American perspective, I still find it wacky that ring circuits would be the favored method in a contemporary installation. No offence was intended and I hope none was taken.

[pb1936]

Crossy........many thanks for your further thoughts which are v. useful.

Cheers, PB

[Crossy]

bankruatsteve, on 03 May 2013 - 11:26, said:

According to Merriam-Webster online dictionary (I find the spelling should be) wacky is defined as: different from the ordinary in a way that causes curiosity or suspicion.

And, from an American perspective, I still find it wacky that ring circuits would be the favored method in a contemporary installation. No offence was intended and I hope none was taken.

No offense (sic) taken, we in the UK wonder why the US has 110V power (safety?) but then has to double it up for big appliances

UK spelling would have the 'h' I think we can agree to disagree on this point

Have a look here for some ring main history http://en.wikipedia.org/wiki/Ring_circuit as to why we have the dreaded beasts.

[citizen33]

(the normal Thai socket has L and N the wrong way around for the UK plug)

I dont have 'normal' Thai socket, I use clipsal (now schneider), which are clearly marked for the terminals for even the most laymen of people.

Yes, I understood that. I just meant that an average person (lacking your knowledge) might just replace an old style Thai socket with a 'clipsal' without realising that the UK fused plug needs the L and N reversed from where the wires were positioned before. Having done that, if you then plug in a 3-pin Thai appliance the 'polarity' is reversed from that intended. As you hint this generally won't matter with modern appliances, although it might possibly cause issues with some audio amps or some specialist test equipment or control circuits.

[bankruatsteve]

bankruatsteve, on 03 May 2013 - 11:26, said:

According to Merriam-Webster online dictionary (I find the spelling should be) wacky is defined as: different from the ordinary in a way that causes curiosity or suspicion.

And, from an American perspective, I still find it wacky that ring circuits would be the favored method in a contemporary installation. No offence was intended and I hope none was taken.

No offense (sic) taken, we in the UK wonder why the US has 110V power (safety?) but then has to double it up for big appliances

UK spelling would have the 'h' I think we can agree to disagree on this point

Have a look here for some ring main history http://en.wikipedia.org/wiki/Ring_circuit as to why we have the dreaded beasts.

Ah yes, we Americans would spell with an 's'. I must have been thinking of English football: no offence. (Well, I thought that was funny.)

As for 110v, I have no idea but it is pretty versatile And, just to say we can save on copper too in that kitchen circuits are recommended (or perhaps required?) by NEC to have one circuit from each side sharing the neutral. ie: 3 wire + ground

[bankruatsteve]

Since this thread appears to have ended, I'll also add that I find it a bit whacky that my British mates (which are the majority these days) can come away absolutely thrilled with a 0-0 tie.

[Crossy]

Since this thread appears to have ended, I'll also add that I find it a bit whacky that my British mates (which are the majority these days) can come away absolutely thrilled with a 0-0 tie.

It really isn't cricket is it?