4 Core Flat Grey Cable

[maverickone]

Found a short length of this in the back of the old shed yesterday whilst having a clear out and haven't a clue where it's come from or what it would have been used for.

It as the normal red,blue and bare earth wire plus a yellow wire and at first when I picked it up I thought it was 2.5mm twin & earth.

Can anyone educate me as to what it is and what it is used for please?

 

[Mottie]

3 core and earth used for two way lighting.

 

[SUNRAY]

3 core and earth used for two way lighting.

or 3 phase
or...
or...

 

[Mottie]

Or what? Does 3 Phase have a bare earth? Does it come in a flat sheathed covering? I thought 3 Phase was three cables and a neutral. Add an earth and that's 5 wires. I honestly don't know as I'm not an electrician but I have seen that wire in my own house when changing two-way light switches. Perhaps an electrician can shed some light on this?

 

[SUNRAY]

Or what? Does 3 Phase have a bare earth? Does it come in a flat sheathed covering? I thought 3 Phase was three cables and a neutral. Add an earth and that's 5 wires. I honestly don't know as I'm not an electrician but I have seen that wire in my own house when changing two-way light switches. Perhaps an electrician can shed some light on this?

3C&E is used in many situations where 3 wires and earth is required such as but certainly not limited to:
2 way switching,
PIR wiring,
3 phase, (when neutral is not required which is fairly frequent), this is probably why the cables do not include a neutral colour?
Heating systems (thermostats, motorised valves, boiler),
2 1gang switches,
Bathroom extractor fan,
Smoke detectors,

The list is endless, especially outside of the domestic scene.

 

[sparkwright]

or 3 phase
or...
or...

I have to say I've never had the nerve to use it to supply 3 phase equipment.

 

[fluorescence]

...It as the normal red,blue and bare earth wire plus a yellow wire...

Red yellow & blue is the 'old' 3 phase cable colours, the neutral would be black if this cable had one. FYI the new EU compliant colours are brown black & grey with blue as the neutral.

I wonder why many people don't like the new colours!!

 

[ericmark]

Red yellow & blue is the 'old' 3 phase cable colours, the neutral would be black if this cable had one. FYI the new EU compliant colours are brown black & grey with blue as the neutral.

I wonder why many people don't like the new colours!!

Since most common colour blindness is red/green the new colours were to get around that problem, however there are no rules as to what colour is used for what except for earth.

Having a cable with three brown or red cores may fit it's use far better, however be it red, yellow, blue, (British) or Brown, Black, Black, (Europe) or new Brown, Black Grey (Harmonised) having the cores with different colours helps identify the cores, we should sleeve the cores, but that is rare except in ceiling rose.

All our site 110 volt supplies should be brown, black, green/yellow, as there is no neutral, try finding yellow cables with those colours or plugs and sockets marked L1, L2 and E nearly every one is marked L and N.

 

[SUNRAY]

Since most common colour blindness is red/green the new colours were to get around that problem, however there are no rules as to what colour is used for what except for earth.

Our old colours were changed in the 60's to a very sensible set of 3 primary colours and a lack of colour neutral. The funny thing is green was used as a phase colour here and ,until very recently, in at least one other European country, so I think it's a good thing that has changed.

Having a cable with three brown or red cores may fit it's use far better, however be it red, yellow, blue, (British) or Brown, Black, Black, (Europe) or new Brown, Black Grey (Harmonised) having the cores with different colours helps identify the cores, we should sleeve the cores, but that is rare except in ceiling rose..

I sincerely hope it happens everywhere and I'd start questioning inspection procedures if not.

.

All our site 110 volt supplies should be brown, black, green/yellow, as there is no neutral, try finding yellow cables with those colours or plugs and sockets marked L1, L2 and E nearly every one is marked L and N.

Should that not be Brown and Grey for 2 phase work? Which I have been issued with, I have also been able to source Brown, Grey & blue for DC use. The connectors 'should' be labelled L+ & N-. + & - being commonplace markings for 2 phase ac use.

 

[SUNRAY]

I have to say I've never had the nerve to use it to supply 3 phase equipment.

Why not?

 

[333rocky333]

It as the normal red,blue and bare earth wire plus

That was never normal, Red and Black was.

The cable you have was initially intended for 3 phase and E, hence the colours, it would possibly be used for a motor supply. as they dont need a Neutral, 4 pin sockets exist for 3 phase and earth.
As said by others smaller sizes tend to be used more commonly for 2 way than actual 3 phase

 

[sparkwright]

Why not?

Probably because I've never seen it done like that, always seen and done singles in trunking or conduit, or SWA.

Somehow looks too domestic.

 

[AndyPRK]

come on guys.

This obviously sounds like flat grey
three core and earth used for lighting.

Unless its round SWA shielded

 

[securespark]

I have to say I've never had the nerve to use it to supply 3 phase equipment.

Why not?

EDIT: Sorry, asked already......

I have seen 2.5 3C&E supplying a small three phase motor.

 

[JohnW2]

come on guys. ... This obviously sounds like flat grey ... three core and earth used for lighting.

As you say, 'obviously', - but who has suggested otherwise?

The title of this thread is "4 core flat grey cable" and the OP described it as:

It as the normal red,blue [sic] and bare earth wire plus a yellow wire and at first when I picked it up I thought it was 2.5mm twin & earth.

Kind Regards, John