T&E Grey/White

[AndyPRK]

Could someone tell me what the differences are between white and grey please. (apart from colour)

Am I correct in thinking

White produces less smoke ?

Grey is a higher temperature rating ?


Would generally like to know, but also thinking in the context of cooker cable.

Thanks

 

[ericmark]

It could be just colour but often white is rated 90 degs C and grey at 70 degs C so white can carry more current.

But don't rely on colour you need to find marking on cable.

 

[RF Lighting]

It depends.

If it is cable from before the core colours were harmonised, then there is no difference at all apart from colour. White tended to be sold in the DIY sheds, and grey at trade outlets, but it was not forced to be.

Now, grey sheathed is standard 70°C PVC/PVC insulated cable, as used in most general installation work.

White sheathed is LSF (low smoke and fume) cable. It operates at a max of 90°C providing the accessory is also rated for this temperature. If there is a fire in the building, and the cable gets burned, it does not produce noxious fumes like standard PVC does.

It is generally only used in public buildings where there is likely to be many people gathered such as schools and theatres etc.

 

[GaryMo]

It could be just colour but often white is rated 90 degs C and grey at 70 degs C so white can carry more current.

That's a little misleading as using conductors rated to 90 deg C at their limit would require the use of accessories also rated to 90 deg C.

I'm sure you know that Eric but I'm just pointing it out to others that may not.

 

[ericmark]

For grey see here

For white see here

So for reference method "A" one is 20A the other is 25A

However be aware not all white twin and earth is:-

Twin & Earth cable, 6242B LSZH cable for domestic wiring

Conductors: Plain annealed copper

Insulation: XLPE (Cross linked polyethylene)

Core identification: Single core (blue or brown), 2 core (blue & brown), 3 core (black, brown & grey)

Sheath/Jacket: LSZH (Low smoke zero halogen)

Colour: White

Voltage: 300/500v

Operating temperature: Maximum 90°C, minimum bending -15°C


Standard: BS7211 Electric cables. Thermosetting insulated, unarmoured cables for voltages up to & including 450/750V, for electric power, lighting & internal wiring, and having low emission of smoke and corrosive gases when affected by fire

BSEN50267-1Common test methods for cables under fire conditions. Tests on gases evolved during combustion of materials from cables. Apparatus
BSEN50267-2-1:Common test methods for cables under fire conditions. Tests on gases evolved during combustion of materials from cables. Procedures. Determination of the amount of halogen acid gas
BSEN50266-1Common test methods for cables under fire conditions. Test for vertical flame spread of vertically-mounted bunched wires or cables

Applications: domestic wiring and lighting systems

 

[GaryMo]

So for reference method "A" one is 20A the other is 25A

So for the 25A one, is it easy to come by accessories with terminals rated to 90 degrees C to use with it (assuming you require 25A from it)?

 

[ericmark]

So for reference method "A" one is 20A the other is 25A

So for the 25A one, is it easy to come by accessories with terminals rated to 90 degrees C to use with it (assuming you require 25A from it)?

Agreed and the use of Ali-tube (also rated 90 degs C) has raised some queries as to how what is around the cable will react with that temperature.

However I have also seen where people have accused the electrician of dangerous practices where they have used 90 degs cable and protected accordingly. I am wary of condemning 6mm cable with 45A MCB when I know it may be only 1A out with method "B" rated at 44A. Also same in reverse I would not rate a white cable at 44A unless I could see markings on the cable.

Years ago the colour was only so it looked better and had nothing to do with materials used. Even today one finds red 13A sockets for sale and one knows they are not 400v it's just because they look good.

It does surprise me with Ali-tube being put forward as the cable for stud walls that the 17th does not include it with method 100 to 103. Maybe it is how it affects other items that has resulted in figures not being released for its use?

 

[ebee]

Grey for the trade and white for DIY

 

[ban-all-sheds]

A ROT which doesn't work well south of Birmingham.

 

[ban-all-sheds]

So for the 25A one, is it easy to come by accessories with terminals rated to 90 degrees C to use with it

No.

 

[ban-all-sheds]

Even today one finds red 13A sockets for sale and one knows they are not 400v it's just because they look good.

You used to be able to get all sorts of primary colours.

In the '80s we had a flat, and we had pale grey walls in the living room (Dulux Dove Grey), with black ash and natural calico furniture, CH rads painted matt black, and red sockets and switches. I remember also getting red plugs, and curly red flex for the TV etc.

Well, even I was young in the 80s...

Dining room had very pale blue walls, and royal blue sockets & light switch. I have a feeling I may still have the blue dimmer switch in a box in the loft.

You can still get colours, but they're all variations on black nickel/gunmetal/satin black/charcoal etc.

 

[ban-all-sheds]

Also same in reverse I would not rate a white cable at 44A unless I could see markings on the cable.

Eric is right, AFAIK - I don't think there's any official standard which says that LSF T/E has to be white, or that white has to be LSF.

Nor that LSF has to be 90° cable, but maybe a consequence of the type of plastics needed for LSF is that it can go to 90°?