Good Technique In Wiring

[petercsea]

Installation of a light with a one-way switch:

http://www.diyfixit.co.uk/diy/electrics/on.../one_way_1.html

[petercsea]

Installing a two-way light switch:

http://www.diyfixit.co.uk/diy/electrics/two_way/two_way.html

[petercsea]

Ceiling rose wiring diagrams:

http://www.ultimatehandyman.co.uk/diy/elec...rose_wiring.htm

[petercsea]

Up to speed with Multimeters:

Continuity and short-circuit testing: (Testing with the power off)

http://www.acmehowto.com/howto/homemainten...titesteruse.php

Understanding the multimeter and using it safely:

http://www.allaboutcircuits.com/vol_1/chpt_3/9.html

[david96]

The Electricians Guide to the 16th Edition IEE Regulations http://www.tlc-direct.co.uk/Book/1.1.htm

Interesting figures on min resistance of an earth electrode, tests are not carried out in Australia on this with normal residential and commercial instalations. The supply authorities regard that the fact that there is an electrode at every instalation and across the supply network at regular intervals plus the fact that the MEN system is mandatory is sufficient.

However if the TT or direct system of earthing is used as in many countries a low earth electrode resistance is important,

so in some cases multiple electrodes would be connected together and buried. A lot would depend on soil conditions. RCDs are mandatory when using a TT system. 200 ohms would be an average for normal damp black soil one would imagine.

[Crossy]

Some interesting stuff here http://www.marcspages.co.uk/pq/0000.htm a bit technical for most, but well worth a look

An interesting article showing why the UK was slow to adopt the MEN system (we call it PME) highlighting the hazard posed by an open neutral in such a system http://www.newscientist.com/article/mg1592...live-wires.html

[Artisi]

Great stuff------>>thanks Crossy and petercsea

I am from the USA and just a novice around home wiring practices and your comment Crossy about the US electrical leads me to ask for a further explanation about the US standards versus the remainder of the known world? I am not familiar with other wiring but am willing to learn.

it's just that their electrical system is so alien compared with the civilised world that it's seriously going to cause confusion to the mortals

Hi Longball,

I think the confusion all began with Tessler and Edison. Tessler wanted a 240 V AC system and Edison wanted a 100 V DC system. Edison thought that the AC system was too dangerous and he used to promote this thought by publicly electrocuting stray dogs to illustrate the danger.

Tesslers argument was that to transmit the electricity you needed to do it at his specification. Edison won originally but then agreed that DC wasn't suitable for long distance transmission. The compromise came as 60 Hz 110V AC.

The British elected 240 V 60 Hz, the most efficient supply for transmission over intermediate distances. The Europeans didn't think that 60 Hz was a good frequency as it didn't fit into the decimal definition, so they elected to supply at 50 hz. I think they regret the increase in cost though. I wonder why they didn't go for 250Volts?

So now we have confusion. Yes. 110V is a safer power supply and is recognised as such by the British but the cost of supplying this over the local grid is very expensive because of energy loss, plus the energy requirements today are much higher. In the US there is a lot of multiphase equipment installed in the homes. In the 220-240 V world not very much for domestic use. Increase the phase numbers supplied and the argument is that you increase the risk.

Then it comes down to fitting the systems for 110v and 220-240V. Thats the real differnce as affecting domestic application and the techniques and safety aspects are quite different let alone the evolved cultural differences with the various authorities.

You have a typo in the above - The British elected 240V 60Hz -- should read 50 Hz - just a nit-pick - but you know the internet "I saw it on the internet so it must be correct"

[petercsea]

Great stuff------>>thanks Crossy and petercsea

The British elected 240 V 60 Hz, the most efficient supply for transmission over intermediate distances. The Europeans didn't think that 60 Hz was a good frequency as it didn't fit into the decimal definition, so they elected to supply at 50 hz. I think they regret the increase in cost though. I wonder why they didn't go for 250Volts?

.......................

You have a typo in the above - The British elected 240V 60Hz -- should read 50 Hz - just a nit-pick - but you know the internet "I saw it on the internet so it must be correct"

Apologies. I wasn't clear on that.

Initially the British elected to use a 60Hz system. Subsequently, there was a proliferation of generating companies and the frequencies they generated their power, including a large area of North Eastern England that was generating at 40 Hz. London at one stage had ten different power frequencies. Standardisation at 50 Hz appeared quite late in the reconstruction of the UK post WW2.

[ChampagneSuper]

Hi,

Great thread chaps, really informative.

Hope this isn't too off-topic but does anyone know where to get, if they exist, electrical regulations for domestic installations.

Ie: Do cable have to be installed in conduits ?

Thanks,

CS

[Crossy]

Great thread chaps, really informative.

Hope this isn't too off-topic but does anyone know where to get, if they exist, electrical regulations for domestic installations.

Ie: Do cable have to be installed in conduits ?

I've tried several routes to obtain the Thai wiring regs, they do exist and apparently are based on the same sources as the Australian AS3000 series regs. so if your wiring follows the Aussie regs you can't go too far wrong.

I've spoken to a couple of industrial electricians (not Somchai wiring ), all of whom say there are regs available, but none of whom have a copy I can borrow, typical. Best I could manage was one chaps training notes which really didn't cut it without the actual text

If anyone has a copy of the Thai regulations that we can copy it would be a useful excercise. Thai text is not an issue, I intend translating pertinant sections anyway.

To answer your question. Cables buried in plaster/screed etc. should be in conduit, it seems that surface mounted TPS is OK naked but personally I'd put it in conduit anyway, it's cheap enough

[david96]

The new 2007 edition of the Wiring Rules has also changed the requirements for wiring installed

near building surfaces. Under the revised standard,the "no protection zone" which existed in the 2000 edition in a straight line above and below electrical accessories such as power points in walls no longer applies. This means that with the exception of narrow areas close to the corners of adjoining walls, and

those along the top of walls, wiring that is near a building surface will require suitable protection from mechanical damage.Where the arrangement of wiring within a building exposes it to risk of damage from nails or screws it must be protected by measures such as an earthed covering, enclosure, or through the use of a RCD with an operating maximum of 30mA.

As a result of this change, wiring near building surfaces in the prescribed zone will require suitable protection from mechanical damage. RCD protection may be the most practical way of complying and should be considered for circuits supplying electrical equipment such as stoves and hot water systems.

Refer to figure 3.3 of the new Wiring Rules and clauses 3.9.4.1 and 3.9.4.2 for more detail.

Source. Electrical Safety Office, Qld Govt, Australia. June 2008.

[petercsea]

Great thread chaps, really informative.

Hope this isn't too off-topic but does anyone know where to get, if they exist, electrical regulations for domestic installations.

Ie: Do cable have to be installed in conduits ?

I've tried several routes to obtain the Thai wiring regs, they do exist and apparently are based on the same sources as the Australian AS3000 series regs. so if your wiring follows the Aussie regs you can't go too far wrong.

I've spoken to a couple of industrial electricians (not Somchai wiring ), all of whom say there are regs available, but none of whom have a copy I can borrow, typical. Best I could manage was one chaps training notes which really didn't cut it without the actual text

If anyone has a copy of the Thai regulations that we can copy it would be a useful excercise. Thai text is not an issue, I intend translating pertinant sections anyway.

To answer your question. Cables buried in plaster/screed etc. should be in conduit, it seems that surface mounted TPS is OK naked but personally I'd put it in conduit anyway, it's cheap enough

Does trunking come under the same definition as conduit?

Thanks

[Crossy]

Great thread chaps, really informative.

Hope this isn't too off-topic but does anyone know where to get, if they exist, electrical regulations for domestic installations.

Ie: Do cable have to be installed in conduits ?

I've tried several routes to obtain the Thai wiring regs, they do exist and apparently are based on the same sources as the Australian AS3000 series regs. so if your wiring follows the Aussie regs you can't go too far wrong.

I've spoken to a couple of industrial electricians (not Somchai wiring ), all of whom say there are regs available, but none of whom have a copy I can borrow, typical. Best I could manage was one chaps training notes which really didn't cut it without the actual text

If anyone has a copy of the Thai regulations that we can copy it would be a useful excercise. Thai text is not an issue, I intend translating pertinant sections anyway.

To answer your question. Cables buried in plaster/screed etc. should be in conduit, it seems that surface mounted TPS is OK naked but personally I'd put it in conduit anyway, it's cheap enough

Does trunking come under the same definition as conduit?

Thanks

The regs usually state 'protection from mechanical damage' so trunking would be ok, certainly better than naked TPS and it tends to look nicer than exposed conduit.