Three core - Grey is generally neutral

[Daniel Oake]

(Just a quick basic question I could google, but I prefer the forum discussion if anyone's wondering)

When installing a feed to something that requires 3 core and earth, why is it we use the grey (as a general rule of thumb) as the neutral (and sleeve blue) instead of the black, I figured black would be more memorable as the old colours, the black is neutral.

Maybe someone has a better insight into it, it's just the videos I watch online and when i'm being taught on site nobody mentions or knows why, when asked.

 

[Michael Sands]

It stems from l1 red now brown
L2 yellow now black
L3 blue now grey
When the colours changed I thought the same as you at first

 

[Pete999]

It stems from l1 red now brown
L2 yellow now black
L3 blue now grey
When the colours changed I thought the same as you at first

Blue is N Grey is a phase colour

 

[Michael Sands]

Not 3 phase
Red yellow and blue are all phase
Now brown black grey
Blue was only neutral in flexes
Red and black wher phase and neutral now brown and blue where is the confusion

 

[Ian1981]

(Just a quick basic question I could google, but I prefer the forum discussion if anyone's wondering)

When installing a feed to something that requires 3 core and earth, why is it we use the grey (as a general rule of thumb) as the neutral (and sleeve blue) instead of the black, I figured black would be more memorable as the old colours, the black is neutral.

Maybe someone has a better insight into it, it's just the videos I watch online and when i'm being taught on site nobody mentions or knows why, when asked.

Regarding 3 core bs6004 cables,There’s nothing stopping you using the black rather than the grey as the neutral as long as it’s identified by the colour blue as required

 

[davesparks]

When installing a feed to something that requires 3 core and earth, why is it we use the grey (as a general rule of thumb) as the neutral (and sleeve blue) instead of the black, I figured black would be more memorable as the old colours, the black is neutral.

There a few different reasons/schools of thought on this.
Firstly it doesn’t technically matter as long as cores are correctly identified at each termination, though in my opinion it’s better to stick to the accepted practice.

Before the change of colours it was common to use blue (core 3) as the neutral due to its use as such in flexible cables. So now that core 3 is grey we use that.
This made even more sense with a 3core SWA where the yellow (core 2) was used as earth.

If you are making a joint from an ryb three core to a new colours one the cores can be made to line up properly, this doesn’t matter so much for flat 3c&e but in bigger cables crossing cores over in a joint may be awkward.

Also it makes sense from a numbering point of view, use cores 1 & 2 for L and core 3 for N.

 

[Pete999]

Not 3 phase
Red yellow and blue are all phase
Now brown black grey
Blue was only neutral in flexes
Red and black wher phase and neutral now brown and blue where is the confusion

New Cable Colour Code for Electrical Installations - https://elise.ema.gov.sg/safety/about.html

 

[Pete999]

Not 3 phase
Red yellow and blue are all phase
Now brown black grey
Blue was only neutral in flexes
Red and black wher phase and neutral now brown and blue where is the confusion

In this post Mate

 

[Michael Sands]

Sorry but I still don’t get your point am I missing something

 

[Pete999]

Sorry but I still don’t get your point am I missing something

Where do you get the idea that the new colour codes, (not really that new) only apply in flexible cords? or vice versa

 

[telectrix]

it's general practice to use the grey as N and black as E (sleeved gn/y, of course). this is to dissociate the black from N as was the case when we used sensible colours.

 

[Michael Sands]

Think you misunderstood the post, back in the day it was only red and black you only seen brown and blue in flex and for referring to new colours I was relating to where the colour choice came from for neutral making reference to new and old does that make more sense now

 

[mickfred]

I always use black as neutral and grey as earth . No reason just always do

 

[westward10]

Think you misunderstood the post, back in the day it was only red and black you only seen brown and blue in flex and for referring to new colours I was relating to where the colour choice came from for neutral making reference to new and old does that make more sense now

No but I am out of breath reading it.

 

[Deleted member 26818]

This practice of using the grey for neutral is something the NICEIC are promoting.
The reason is to de-neutralise (their word not mine) the black.
Ask them to explain why we need to de-neutralise the black, and you’ll get a load of waffle.