Electric wiring colour coding rainbow

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Electric wiring colour coding rainbow

Postby ratsima » Fri Jun 12, 2015 11:17 am

Our new build house in Bangkok is getting close to the finish. The electrician had already been before the floors and tiles had been laid to put the main infrastructure in, then later he did a few outlets and switches in the top floor (which had been finished first). He has about 6-8 guys in his team. we have used this guy and hos team for various remodelling projects over the past 6 years.

As he was coming this morning to discuss the final work, I decided to have a look round at the spaghetti still hanging from the socket and switch outlets. I took a couple of front plates off to check what had been done on the top floor. I was gobsmacked at the number of colours in use and the apparent lack of a pattern. However, today I learned the pattern and I'm still a bit gobsmacked!

The electrician insists that the colour coding rules are green for earth and white for neutral. However, he says the live cable colour can be selected from among a wide range of colours - red, blue, yellow, grey. No special colour for switched live. So, his team uses a different colour for live depending on which floor/zone, so they can pull it all together correctly at the distribution box. It sound slike a neat idea but can this be right? I had expected four colours for the electrcial circuits- live, neutral, earth, switched live. As it happens the colours are "all over the place" (literally) with a large preponderance of yellow cables.

I'm a bit worried /wary. Otherwise, we have fair confideence in this guy who does regular installations at new bank branches, so he's not a dummy. And there's so much work going on he doesn't really need our business.....

Any comments please to allay or increase my concerns! Many thanks...
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Re: Electric wiring colour coding rainbow

Postby schuimpge » Fri Jun 12, 2015 12:18 pm

Never looked at it that way for normal AC-wiring, but on your questions:

Green or Green/Yellow is the all common ground indeed. No problem there.
White for Neutral? Nope.. Blue is neutral in most of the standards (some give black or blue as option) except USA / Canada where they use silver.
Old School used black for neutral in many countries.

For Live-wires, there are many different colours used, but the problem is, that it's mostly different COUNTRIES that use different colours.
So for 1 country, typically there's only 3 sometimes 4 different colours available for live-wires.
If he'd really follow code, then he'd use 1 colour only and a simple tester with a label to each wire.

His approach is nice, but the problem is, a new electrician (for example a year from now to connect a new Air-Con), would have major issues connecting something safely if he's following standards only versus your Sparky doing his own little inventive ideas.
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Re: Electric wiring colour coding rainbow

Postby thailazer » Fri Jun 12, 2015 7:31 pm

ratsima.... Sounds like your guy is on a good plan. Keeping track of the loads going to a given breaker are tough, so numerous color choices is smart and will help you in the future if the need arises. We used white for all of our neutrals which is a standard here in Thailand. If you are using RCD breakers, make sure that each circuit has a dedicated neutral. You can not share neutrals if using RCD (RCBO) breakers.
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Re: Electric wiring colour coding rainbow

Postby schuimpge » Fri Jun 12, 2015 8:01 pm

Both my houses where done by the same people. Their method was very straight forward, GC would place and pull all the wires from outlets to the mains. Then put a bit of tape with a marking on both sides..Sparky comes in at the end of the project and start checking and connecting. Not sure? Connect two wires at the outlet and use a volt-meter at the mains box to double-check with the standard "beep" function you find on every meter.
All wiring in the houses is done with green, white and black. Never had a single problem
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Re: Electric wiring colour coding rainbow

Postby schuimpge » Fri Jun 12, 2015 9:52 pm

Give you a nice example..

Say, normally they use blue PVC for water and the yellow PVC for electricity.

So relating that back to your inventive sparky..
He changes that (maybe because of a special deal on the blue PVC being much cheaper) and next time someone comes to install a new tap...
Worker one: did you shut down the pump?
Worker two, yes I did, go ahead and cut that pipe!

Worker 1 starts hacking about in the (blue) water pipe..
You'll imagine what happens next...

Color coding standards are there for a reason.
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Re: Electric wiring colour coding rainbow

Postby thailazer » Sat Jun 13, 2015 7:07 am

schuimpge wrote:Give you a nice example..

Say, normally they use blue PVC for water and the yellow PVC for electricity.

So relating that back to your inventive sparky..
He changes that (maybe because of a special deal on the blue PVC being much cheaper) and next time someone comes to install a new tap...
Worker one: did you shut down the pump?
Worker two, yes I did, go ahead and cut that pipe!

Worker 1 starts hacking about in the (blue) water pipe..
You'll imagine what happens next...

Color coding standards are there for a reason.

I think you may be confused about the original post. He is referring to the insulation color on the wires, not the conduit. There is not mention of conduit color there in the OP, but yellow is the color to use for conduit.
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Re: Electric wiring colour coding rainbow

Postby schuimpge » Sat Jun 13, 2015 8:46 am

Hello Thailazer.. I only gave that as an example to get my point across.. I know he's talking about colour of the wires, not the conduit.
It's just not good practice for wiring. You can't start making up your own coding if you expect someone else in the future to work on it.
Asking for accidents in the future.
Personally, I really like that idea, but you shouldn't do that unless you are sure you're the only one ever working on it with future extensions.

Cheers,
Luc
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Re: Electric wiring colour coding rainbow

Postby canopy » Sat Jun 13, 2015 9:58 am

Ignoring the fact it goes against conventions (of which there are very good reasons to comply), it sounds pretty dangerous. A problem with this coloring system is it only keeps track of the hot wires. So the ground and neutrals can be mixed and matched as there are no such identifiers. This can lend itself to dangerous thai practices such as a shared neutral. So when you turn off a breaker the neutral wires on that circuit can be hot! Or when you disconnect a ground, you may end up ungrounding half the outlets in the house. Why not use 2+1 romex cables and tape the circuit color on the outside of the cable. Inside the cable, the colors of each wire all remain consistent and standard.
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Re: Electric wiring colour coding rainbow

Postby Sometimewoodworker » Sun Jun 14, 2015 10:07 am

canopy wrote: Why not use 2+1 romex cables and tape the circuit color on the outside of the cable. Inside the cable, the colors of each wire all remain consistent and standard.

there is a really good reason why that is not a good idea.

Try pulling 2+1 romex cable through 10metres of conduit with bends. Then do the same with 3 single cables :roll: :roll:

Not all Thai ways are bad. :D
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Re: Electric wiring colour coding rainbow

Postby canopy » Mon Jun 15, 2015 8:38 am

One thing they may do in that case in other countries is simply up-size the conduit and of course always use the long bends, not the short ones. Makes a huge difference. Another thing they may do is use a different cable type certified for use without conduit in the given application.

Can't help but smile when I read about this Thai color coding approach. It would make so much sense to them because when finished, the electrical will work, at least to a point and that's all they are there to do. Down the line problems lurking in the crossed up neutrals and grounds could show one by one at any time and you deal with them and always the danger of electrocution.
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