Old colours to new with different cores

[bobpants75]

Hi,

I had some nice shiny new re-inforced electric mains cables put into my shed...

which are BROWN, BLACK & GREY with outer re-inforcing metal strands around the cable.

All good, but I just bought an old water pump that has wire RED, BLACK & YELLOW / GREEN.

So I guess I have an old 2 core to attach to a new 3 core. How do the colours connect in this kind of setup please?

I have checked some other posts but they don;t seemt o entirely mirror my scenario.

Thanks in advance

Thanks
Bob

 

[holmslaw]

..

 

[stargazer]

I had some nice shiny new re-inforced electric mains cables put into my shed...

That's nice. Who did that?

which are BROWN, BLACK & GREY with outer re-inforcing metal strands around the cable.

Sounds like 3 core SWA.

All good, but I just bought an old water pump that has wire RED, BLACK & YELLOW / GREEN.
So I guess I have an old 2 core to attach to a new 3 core. How do the colours connect in this kind of setup please?

The convention is, with single phase SWA, to sleeve black cable with green and yellow and use it as the protective conductor. The grey is sleeved blue and used as the neutral conductor. The brown is the phase (live) conductor.

So ASSUMING this is what you’ve got, you wiring will be

Red from pump > Brown of SWA
Black from pump > Grey of SWA
Yellow / green from pump > Black of SWA

There is much more to consider than that, including

How are you going to make the connections?
What overcurrent and other protective devices will be incorporated into this new circuit?
Have you considered Part P?
Have you considered getting an electrician in?

 

[Chri5]

The cable with black, brown and grey is 3 core- normally used for 3 phase work.

However even though the SWA steel must be earthed (and is a earth conductor) sone run in 3 core and use one of the cores for earth.

You need to look at the point in the house where the wires terminate to 100% know what's happening re: colour V use.

Red, yellow and Blue phases correspond to Brown, Black and Grey.

That's of no interest if you are running simple domestic 1 phase.

On the pump, red = live, Black+ Neutral and G/Y = earth.

Pictures of the glanding of the SWA will establish the SWA as earth. And a picture of the termination position and colours used at the house end will establish the colours use and the LNE positions.

 

[ban-all-sheds]

Hi,

I had some nice shiny new re-inforced electric mains cables put into my shed...

Who did that, and where/how did they terminate it? Why did they not mark the cores? Or is it actually a 3-phase supply? From where and how is it supplied? Pictures would be very useful. Of both ends.

What was the intended use of this cable once it got to the shed?

which are BROWN, BLACK & GREY with outer re-inforcing metal strands around the cable.

All good, but I just bought an old water pump that has wire RED, BLACK & YELLOW / GREEN.

1) Why have you got a water pump in the shed? (This is actually very important, depending on why/how used, what type of supply you have and whether you told the electrician who installed the cable what you'd be doing).

2) How would you have connected up the water pump if you'd found the old colours in the cable, i.e. red, yellow & blue?

So I guess I have an old 2 core to attach to a new 3 core. How do the colours connect in this kind of setup please?

Ditto Q 2.

Basically you do need to have some sort of knowledge to be able to do wiring safely.

We can all make a reasonable guess about which core is which, but I'm not going to post my guess here, because if I guess wrong you might die.

If you can't look at the other end of the cable and see which core is which then I suggest you get an electrician in to sort it out for you.

 

[bobpants75]

Wow! Thanks everyone - this gives me some ideas - I will delve a bit deeper into the other end of the wire to be sure (with it switched off ) and then go from there.

 

[ban-all-sheds]

You have left a number of important (possibly as in life & death, and that is not an exaggeration) questions unanswered....

 

[mikhailfaradayski]

Hi Bob,

It seems that there a few people interested in how the cable got there.

Would you mind giving us some information regarding this, it may help/influence the advice you receive.

This will help you

 

[mikeyd]

Hi,

I had some nice shiny new re-inforced electric mains cables put into my shed...

...


So I guess I have an old 2 core to attach to a new 3 core. How do the colours connect in this kind of setup please?

Bob

You have 3 core (+ outer armour) to connect to 3 core.
In the olden days, red was live, black was neutral and green/yellow was earth. If you have no way of checking/testing which of the white/grey/black in your new cable is which conductor then you are maybe out of your depth.

Ask the person who installed the cable back to connect it up for you.

Sorry if this seems blunt but there is no way to tell you how it was wired,

 

[ban-all-sheds]

In the olden days, red was live, black was neutral and green/yellow was earth.

I don't think 3-core SWA ever came in those colours, did it?

 

[RF Lighting]

I think you could get it made to order, but certainly not a standard cable, and something I've never seen in my life....

 

[ericmark]

The convention is, with single phase SWA, to sleeve black cable with green and yellow and use it as the protective conductor. The grey is sleeved blue and used as the neutral conductor. The brown is the phase (live) conductor.

Because the neutral was always Black many still use this as neutral and so I would say it would be dangerous to assume what the grey and black are used for with a single phase supply.

In theory all unused cores should be earthed but in practice this is often not followed so to assume any of the cores are earth would also be dangerous.

There is only one way and that is to inspect and test and fit the correct colour sleeves. Very likely the Brown will be "Line" (We do not use word "Live" to refer to a phase conductor as the neutral is also classed as "Live".

With Earth and Neutral crossed many items could still work and until a second fault occurs no one may realise. Then when second fault does happen some one is electrocuted.

As ban-all-sheds has already stated

We can all make a reasonable guess about which core is which, but I'm not going to post my guess here, because if I guess wrong you might die.

I have seen some really odd wiring in the past enough to know you don't guess.

 

[ban-all-sheds]

Hi,

I had some nice shiny new re-inforced electric mains cables put into my shed...

When you had that done, what did you ask the guy who did it to provide?

Sockets? Lights? A CU in the shed?

I'm struggling to understand how an electrician would just leave the cable dangling there.

What did he gland it to when it got inside the shed?

 

[mattylad]

Yes - need more information & pics from the original poster.


BAS - Is a cable with those colour cores contrary to what the law says can be used?