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#161203 - 03/31/07 09:17 AM Whatever happened to LIGHT blue?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
O.K., it's no secret that I'm not a fan of the harmonized European color code, but as we're stuck with it now, I have to ask this question.

When flexible cords adopted brown/blue in the early 1970s all the specifications stated that the neutral conductor should be light blue. Look at those earlier flexes and the blue conductor was indeed -- to a greater or lesser degree -- a fairly light shade of blue.

Over the years though, we seem to have slipped into using much darker shades of blue. I've noted this before, but what really prompted me this time was seeing the newly installed tails on a recent project now that the new colors are being applied to fixed wiring as well.

The Siemens guy marked up the meter tails with tape to the new colors, and at first glance I actually thought he'd used brown and black.

It wasn't until I got up close that I realized the neutral was actually a very dark shade of blue (and the tapes he used did have L and N stamped all along them too). Now that black has become a phase color, about the last thing we need is blue identification tape or insulation which is so dark a shade of blue that it appears to be almost black in poor light.

So I have to ask: Whatever has happened to the requirement that neutral should be identified by light blue?

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#161236 - 03/31/07 04:39 PM Re: Whatever happened to LIGHT blue? [Re: pauluk]
RODALCO Offline
Member

Registered: 12/08/05
Posts: 863
Loc: Titirangi, Akld, New Zealand
Good point you raised there Pauluk.

It used to be light blue for Neutral, now most flexible cords have gone to dark blue which is not correct.

Dark blue is a phase colour here in NZ.

Red, Yellow, Blue for 3Ø supply.
_________________________
The product of rotation, excitation and flux produces electricty.

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#161247 - 03/31/07 06:45 PM Re: Whatever happened to LIGHT blue? [Re: RODALCO]
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Good point indeed Paul,
IMO it is up to the cable manufacturers to ensure that the colouring of the insulation meets the specification given to them for making these cables.
I've noticed a lot of the White Phase colouring on middle conductors, is often tinged with other colours.
But, right, Light Blue is Light Blue, not dark blue.
I haven't used a lot of flex cable recently so I can't really comment on the colouring of the Neutrals in them.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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#161268 - 04/01/07 02:31 AM Re: Whatever happened to LIGHT blue? [Re: Trumpy]
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
 Quote:
it is up to the cable manufacturers to ensure that the colouring of the insulation meets the specification


Yep. Same as we've mentioned before about green/yellow earth conductors. The specification says that one color must be at least 30% of the surface area, yet I keep finding cables which are mostly yellow with just a small (much less than 30%) green stripe. \:\(

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#161450 - 04/03/07 04:59 AM Re: Whatever happened to LIGHT blue? [Re: pauluk]
djk Offline
Member

Registered: 12/26/02
Posts: 1269
Loc: Ireland
It comes down to enforcement of standards by the national bodies. It really should be done. Getting plastic colours correct isn't that difficult in this day and age.

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#161454 - 04/03/07 05:30 AM Re: Whatever happened to LIGHT blue? [Re: djk]
Wolfgang Offline
Member

Registered: 09/25/05
Posts: 154
Loc: the very West of Germany
Sorry to say, but the word light has definitely been removed from the standards at the time when solid (conductor) cables were harmonized. So any blue is neutral now.
This causes problems here in Germany where dark blue means usually = 24VDC.

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#161543 - 04/04/07 03:16 AM Re: Whatever happened to LIGHT blue? [Re: Wolfgang]
kiwi Offline
Member

Registered: 12/04/04
Posts: 347
Loc: christchurch new zealand
When we build a control panel for the european market, the consulting engineer requires us to use light blue cable for neutral. Light blue cable is hard to find and if the phases are black then why does it have to be "light blue". Is the consulting engineer just being overly fussy ?

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#161544 - 04/04/07 03:19 AM Re: Whatever happened to LIGHT blue? [Re: Wolfgang]
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Ah.... Danke Wolfgang. So the standard no longer specifies light blue?

Bad enough that we're stuck with such a mish-mash of colors that blue could be phase or neutral, but now we can have blue that's so dark it's almost black. And black is neutral of course..... Or is it a phase?

What a mess!

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#161602 - 04/05/07 02:26 AM Re: Whatever happened to LIGHT blue? [Re: kiwi]
RODALCO Offline
Member

Registered: 12/08/05
Posts: 863
Loc: Titirangi, Akld, New Zealand
Just had a look at the AS/NZS 3000:2000, page 87.
Table 3.5
Colours of cable cores.
Function__Recommended__Alternative
Earth/____Green/yellow__Green

Neutral____Black________Light Blue

Active______Red________Any colour except green/yellow, green, yellow, black, light blue.

And i'm sure there was an other amendmend that yellow was also re allowed as a phase colour because of complaints from electricians in the trade, and manufacturers who had stacks of yellow cable in stores which was supposed to become the white colour for the L2 Phase.
_________________________
The product of rotation, excitation and flux produces electricty.

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#161603 - 04/05/07 02:44 AM Re: Whatever happened to LIGHT blue? [Re: RODALCO]
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Ray,
I'm in the same boat as you as far as these colours go.
Look, we survived quite nicely with Red, Yellow and Blue as our 3 Phase colours.
Also 1 Phase colours were Red, Black, Green, no matter wether they were in a flex or in a fixed cable.
OK, where we screwed up was changing our colours over to the EU colours of Brown, Light Blue and Green/Yellow.
I've never liked that combination, because older folks here don't know what colours mean what, add to that failing eyesight.
But apparently some person thinks that Brown and Light Blue are most easily distinguished by colour blind people.
Tell me this guys, what is a colour blind person doing mucking around with coloured wires for?.
Same side of the coin, it's made things harder for us Electricians where some clown has used a striped wire as a Phase(switch wire) and you cut it in the middle of a run, watch out!!.
I sat a colour-blindness test before I started my apprenticeship, who tests home-owners?.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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