≥6-core flex?

[JohnW2]

Hi folks,
I asked a similar question a few years back, and I suspect that the answer hasn't changed much since then, but ...

...I need a small length of ≥6-core (well, ≥5-core + earth) mains-rated cable, presumably flex (for use in a 6A lighting circuit), but life starts getting more difficult beyond 5-core (or 4C+E). There's plenty of 6- and 8-core (and beyond) out there called alarm/signal cable and, whilst a fair bit of that is only 'rated' for ELV, some claims to be LV-rated (commonly "500V") - but that usually has only 0.2 mm² conductors.

As was the case those years ago, one exception is a 7-core 0.75 mm² flex offered by TLC with 6 black-insulated (numbered) cores and one G/Y one -and seemingly an OD of only 7.7 mm. That would certainly do the job, although I suppose I'd be even happier if the cores were not all black. Is anyone aware of anything else which is currently available (in short lengths) ? The TLC one ...

 

[pete01]

YY or SY?

 

[JohnW2]

YY or SY?

The one from TLC I illutrated (with the 6 back cores) is YY.
I've yet to find an SY with more than 5 cores, but I haven't looked too hard yet!

 

[pete01]

SY7X75 | SUPERLEC | Flexible SY control cable Copper Braid screen, PVC Insulation and PVC Sheath | 7 Core SY Cable .75mm | Flexible Control Cable | SY Control Cable | multicore instrumentation c able -Superlec Direct

www.superlecdirect.com

 

[JohnW2]

SY7X75 | SUPERLEC | Flexible SY control cable Copper Braid screen, PVC Insulation and PVC Sheath | 7 Core SY Cable .75mm | Flexible Control Cable | SY Control Cable | multicore instrumentation c able -Superlec Direct

www.superlecdirect.com

Thanks.

However, I didn't explain, but the reason I want this is because I want to get 5 cores (+ earth) to a (will be 2-gang) light switch which currently is a 1-gang "2-way" one connected with 1mm 3C+E which gets there through some ancient and small buried metal conduit. The current cable seems to be 'mobile' within the conduit, so I have some hope that I will be able to use it to pull a new cable through - but that's most likely to work if the new cable is as small and as flexible as possible.

For that reason I don't think that SY, with its greater size and armour, would be a very clever idea, but the YY could well be the best bet?

 

[plugwash]

I think for "euro spec" mains cables numbered cores are the norm once you go over 5 core.

I suspect the cable TLC are selling is "as good as any" for the task you have in mind.

 

[JohnW2]

I think for "euro spec" mains cables numbered cores are the norm once you go over 5 core.

Fair enough. I suppose one fairly soon runs out of easily-distinguished colours if one gets much beyond 5.

I suspect the cable TLC are selling is "as good as any" for the task you have in mind.

Yep, that's how it also seems to me. Interestingly, I've just looked back and it was 2019 when I previously asked a similar question (for a totally different reason), and the "as good as any" answer was the same back then!

 

[SUNRAY]

Annoyingly I gave away a 15m length of 7C 0.75mm² YY last summer for a rotator using a 6 pin plug, it turned out it only required 4 wires.

FWIW I've used significant quantities 19C & 37C SY and YY cable for 6 and 12 channel lighting. I've used sizes up to 10mm² but no idea what the limit is.

There are 12 common colours, the standard international electrical colour code plus pink and turquoise.

 

[SUNRAY]

Thanks.

However, I didn't explain, but the reason I want this is because I want to get 5 cores (+ earth) to a (will be 2-gang) light switch which currently is a 1-gang "2-way" one connected with 1mm 3C+E which gets there through some ancient and small buried metal conduit. The current cable seems to be 'mobile' within the conduit, so I have some hope that I will be able to use it to pull a new cable through - but that's most likely to work if the new cable is as small and as flexible as possible.

For that reason I don't think that SY, with its greater size and armour, would be a very clever idea, but the YY could well be the best bet?

Is the conduit continuous? Could you use singles?

 

[JohnW2]

Is the conduit continuous?

I would imagine so, but can't be certain. It's only a (straight) run from ceiling level to a light switch and, even those it's a very tall oom, is no more than about 1.5m. However, it's ancient and has been 'plastered in' with something resembling concrete - so if I attempted much excavation, I probably might as well rip it all out and make a chase for a couple of cables (one 3C+E and one T+E)!

Could you use singles?

I very much doubt it. The conduit is tiny - around 16 mm OD, maybe a little less, so probably no more than about 14 mm ID at most. That's OK for the present 3C+E, but I don't think it would be sensible to even think of trying to get a second cable into it, or 6 singles, would you? On the other hand, provided it will pull through OK, the YY cable of alleged 7.7 mm OD ought to be fine?

 

[SUNRAY]

I would imagine so, but can't be certain. It's only a (straight) run from ceiling level to a light switch and, even those it's a very tall oom, is no more than about 1.5m. However, it's ancient and has been 'plastered in' with something resembling concrete - so if I attempted much excavation, I probably might as well rip it all out and make a chase for a couple of cables (one 3C+E and one T+E)!

I very much doubt it. The conduit is tiny - around 16 mm OD, maybe a little less, so probably no more than about 14 mm ID at most. That's OK for the present 3C+E, but I don't think it would be sensible to even think of trying to get a second cable into it, or 6 singles, would you? On the other hand, provided it will pull through OK, the YY cable of alleged 7.7 mm OD ought to be fine?

My experience of 3C&E Vs singles in tube is: 7 singles if drawn in carefully is easy. My first house had lighting circuit in 5/8" split tube which is what I assume you have.
Much had been changed meaning the switch by the front door had 2 1/0.044" T&E in the drop which was quite difficult to pull out. Other than knowing the outside light SL was definitely at the switch I can't recall exactly how it was wired... I put a 3gang switch there,all used as 2 way and 2 of those included intermediate switches but that was at least 8 wires and installed single handed.

From my elderly OSG 16mm tube has a factor of 290 so cable factor of 48 or less for 6 wires or anything up to 2.5mm² stranded.
1mm² solid is a factor of 22 or 13 wires

 

[AndyPRK]

The main one is for heating control. 5 core.
or look at the voltage spec of towbar / traffic light cables. 7 Core These should be available in short lengths

 

[oceansoul]

Instrument or controls cable is probably the best your are going to find.
RS Stock No.: 276-0949 says 6 cores although the picture shows brown black grey blue and earth. Perhaps you could find someone selling an off cut of this or similar.