Sub main cable type

[NDG Elecs]

Hello Good Folks!
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I am a humble domestic spark that is not the most experienced (although not a Electrical Trainee!). I tend to do board changes and smaller stuff. An existing customer has asked me to rewire a couple of flats, one of the flats already has a new sub main ran in by the builder. The cable looks to be YY type, NOT armoured, is defo 16mm 3 core, but looks to have no mechanical protection and is prob <50mm from wall surface. The runs are around 8m for each flat.

YY cable is listed as a control cable rather than a power cable, so if this cable is indeed YY then is it suited as a sub main cable?* There is writing on the cable but I could not get through to investigate due to room full of carp. I will do so in due course.
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16mm YY cable is good for a max of 82A (these are one bed flats with kitchen/lounge as one room (so demand won’t be heavy)). DNO should be happy with 16mm I would assume if 60A supply requested. There is a separate 16mm earth also ran in.

So my question is *would a 100mA RCD up front provide sufficient protection or should the YY be replaced with SWA. No intake is present as of yet as being installed soonish I believe.

For the other flat I was going to run in 16mm 3 core SWA with a KMF up front. I am going to ring NAPIT technical on Monday but I know for sure they will probably say don’t put a 100mA up front despite the fact that there will be two 30mA at board.
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Thoughts welcome please (even OJL!!)

Thanking You!

 

[Silly Sausage]

Thats sy not yy. Yy is bassically flex

Balls! Damn this cider!

 

[Dcf]

The last 2 big shop fits I've noticed have been all yy.
as above I thought wtf is that .
seems to be the cable of choice on commercial for some reason that escapes my humble opinion.
i agree it's an control cable.

 

[NDG Elecs]

The last 2 big shop fits I've noticed have been all yy.
as above I thought wtf is that .
seems to be the cable of choice on commercial for some reason that escapes my humble opinion.
i agree it's an control cable.

I suppose if it's suitably contained it is no different to T&E being used. It will obviously be easier to dress than SWA. When I googled YY it does seem to be getting used a bit in risers.

I should have took a piccy of the cross section of the cable, it is insulated and then has the fattest sheath I have seen on a cable.

 

[Engineer54]

You sure it was control wiring YY cable?? generally the cores would be black with printed core numbers in white. Probably just standard flexible harmonised colour cable!!

One things for sure, if i ever saw a Subby wiring one of our concessionary area shops in any form of flexible extention type cord cabling, he'd be thrown off the project head first, followed swiftly by his crap cable!!

 

[NDG Elecs]

You sure it was control wiring YY cable?? generally the cores would be black with printed core numbers in white. Probably just standard flexible harmonised colour cable!!

No not 100%. It had harmonised insulation. From what I gathered YY cable has numbered cores or harmonised colours instead. The sheath must have been 6mm thick at it's thinnest part. Sheath was light grey and spending an hour googling earlier led me to the YY. Strands on the conductors were very fine which made the csa look tiny.

I am gonna go back and have another butchers.....bet it is just flex afterall!

 

[Des 56]

So my question is *would a 100mA RCD up front provide sufficient protection

If the cable is not mechanically protected or deeper than the magic 50mm then it would have to be 30m/amp for the buried cable
That would be a possible rip it back out value unless the cable is suitable for burial (mmm that last word of mine sounds a little morbid

)

 

[Engineer54]

No not 100%. It had harmonised insulation. From what I gathered YY cable has numbered cores or harmonised colours instead. The sheath must have been 6mm thick at it's thinnest part. Sheath was light grey and spending an hour googling earlier led me to the YY. Strands on the conductors were very fine which made the csa look tiny.

I am gonna go back and have another butchers.....bet it is just flex afterall!

I wouldn't mind betting that at all either!! I also bet that on those shop installs, not a single crimp ferrule was seen either?? lol!!

 

[shanky887614]

No not 100%. It had harmonised insulation. From what I gathered YY cable has numbered cores or harmonised colours instead. The sheath must have been 6mm thick at it's thinnest part. Sheath was light grey and spending an hour googling earlier led me to the YY. Strands on the conductors were very fine which made the csa look tiny.

I am gonna go back and have another butchers.....bet it is just flex afterall!

Sounds like yy were the core colours

Red, white etc

Or black with numbers in white?

 

[guest119]

It sounds like nornal everyday 16mm YY, harmonised.
You can order it coloured cores or numbered.
16mm can be found in many supermarket bakeries feeding the ovens from bus bar it the ceiling or feeding lighting bus bars in the main sales areas etc etc.

Boydy

 

[Engineer54]

It sounds like nornal everyday 16mm YY, harmonised.
You can order it coloured cores or numbered.
16mm can be found in many supermarket bakeries feeding the ovens from bus bar in the ceiling or feeding lighting bus bars in the main sales areas etc etc.

Boydy

No different from a cooker being fed from a 45A cooker control switch!!

Feeding a general area lighting busbar system is another kettle of fish, in my book. ...As i said, it wouldn't happen on any of my projects, not in any way, shape, or form!! lol!!

 

[NDG Elecs]

Just a quick update for anyone interested.

Managed to inspect the cable properly today. Cable has no extra protection and snakes all over the place. Certainly wouldn't wanna be putting any shelves up! Defo YY 16mm harmonised. Told client the bad news and he seemed ok with my proposal to replace it. So happy days!

Thank you all for ya help

 

[Knobhead]

Good outcome for you.

And a bit of scrap for the drinks fund.