Simple question.
If the neutral conductor MUST be black, why is cabtyre flex manufactured with a blue neutral conductor ?
Simple question.
If the neutral conductor MUST be black, why is cabtyre flex manufactured with a blue neutral conductor ?
Safety and Color Blindness: The change to blue for neutral was partly motivated by the difficulty some individuals with color blindness have in distinguishing between black and red.
SABS/SANS become less relevant as we move towards IEC and European standards, there could be a lot of changes happening.
Circuit breakers fed from the bottom or the centre, instead of top to bottom.
Last edited by Tradie; 05-Apr-25 at 04:33 PM.
The European and UK regs(IEC 60204-1 & BS7671) harmonised the phase and neutral colours about 20 years ago which is why you see cables with the blue designated as neutral. The Americans under NEC regs still use white as neutral as far as I know and the Aussies use the original colour scheme with black as N and red, white, blue as phases. Cabtyre and most other trailing cables will be manufactured to the specifications of the bigger markets so they usually come as the harmonised EU colours.
To play it safe, regardless which colour codes the cables are we usually label all the wires at the terminations with N and L1, L2, L3 to avoid any confusion or incorrect connections on site. Likewise when working on something we didn't install I'd never assume which colour is neutral (even if it's labeled) I'd always test to prove it, I regularly come across cables with harmonised EU colours connected with neutral as black and blue as L2.
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We still use the same colours
L1 - red
L2 - white or yellow depending on the cable supplied.
L3 - Blue
Neutral - black
yellow/green - earth.
We also use white or yellow or blue as a return colour for light circuits, which in the past has created some confusion where a customers has used a handyman to replace a light fitting, then I return to the site at some stage to find blue of the light cable is connected to the blue return from the switch, which creates an extremely dangerous situation, especially if it is ES type lamp holder.
One of the reasons it is so import to stick to a colour or number system, phase rotation. We make sure the incoming phase rotation is correct and stick to the colours.
If a machine requires a phase swop, we do it on the machine side of the wiring, not the machine supply cable. Some of the machine cannot run anti clockwise without damaging components.
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