Difference between NYY-J and NYM-J

[spacey3]

I was trying to find out what is the difference between the two types of cable standards, but either I'm looking in the wrong place but not much seems to come up to explain the difference between them.

Can anyone explain?

 

[Risteard]

NYY-J is commonly referred to as Hi-Tuff. NYM-J is a white cable which is not designed for external use.

 

[Nozzle]

Farnell says NYY Is fire retardant PVC 1000V, NYM ordinary PVC 500V

Nozzle

 

[spacey3]

https://lapplimited.lappgroup.com/products/european-power-cable.html

Doesn't give much information away about either of them, other than one is buried in the wall under plaster and concrete and the other states similar.

 

[Risteard]

NYM-J is very widely used on the side of the border one-and-a-half miles from here. On this side, Hi-Tuff is used quite a bit for some applications. As I said, NYM-J is not UV tolerant and should not be used externally (although unfortunately sometimes is).

 

[spacey3]

Curious then, NYY is preferable to use as it only costs €5 per 50m more.

I had one other question, using either of these cables, in a new kitchen installation with sockets and all appliances, dishwasher, washing machine, fridge freezer. I note that most Radial circuits are run at 4mm cable rather then the 2.5mm. Is it better to run the 4mm on a 32amp fuse or two circuits of 2.5mm on two 20amp fuses? separating out the appliances from the sockets.

 

[EFLImpudence]

I had one other question, using either of these cables,

Why not use T&E?

in a new kitchen installation with sockets and all appliances, dishwasher, washing machine, fridge freezer.

A normal kitchen.

I note that most Radial circuits are run at 4mm cable rather then the 2.5mm.

If 32A then it would have to be 4mm² (method C).

Is it better to run the 4mm on a 32amp fuse or two circuits of 2.5mm on two 20amp fuses? separating out the appliances from the sockets.

Depends what you mean by better - and how your appliances are arranged.
Two 4mm² radials would obviously be 'better' than two 20A. One 4mm² radial would likely suffice.

It is up to you to design to supply what you need.

 

[spacey3]

Pretty much a standard kitchen, can't think of anything special that will end up in it, maybe a coffee machine plumbed in if I get my way but that's all I can think of.

The NYY cable is actually cheaper for me to get than T&E anyway, plus it allows me to get it buried under

https://www.ecoglas.de/shop/schaumglasprodukte/ecoglas-schaumglasschotter-10-60-mm.html

which is what will end up in the bed of the floor once the joists are removed and a Lime Screed floor is in place (albeit will conduit).

I think I agree the 4MM cable with a 32amp seems to be sufficient from what I have seen and read.

I will supply the materials and will probably tack and lay it to the floor before they come and finalise everything. I made sure when the consumer unit was changed it was changed to one with excess capacity, so have a bank of RCBO's for one side and MCBs on the other. I believe there are three spare on each to use. Will place it on the RBCO side just incase anything trips it doesn't take out the fridge etc all at the same time, unless the lot goes.

https://www.elektrotresen.de/Kabel-...-3x-4-RE-S-Starkstromkabel-NYY-J-3x-4-RE.html

 

[EFLImpudence]

The NYY cable is actually cheaper for me to get than T&E anyway.
https://www.elektrotresen.de/Kabel-...-3x-4-RE-S-Starkstromkabel-NYY-J-3x-4-RE.html

If you are only buying an odd small amount it may cost less than a reel, but it's not cheaper.

 

[spacey3]

Why not use T&E?


A normal kitchen.


If 32A then it would have to be 4mm² (method C).


Depends what you mean by better - and how your appliances are arranged.
Two 4mm² radials would obviously be 'better' than two 20A. One 4mm² radial would likely suffice.

It is up to you to design to supply what you need.

It all arrived yesterday, I ended up with the 50 meters of 3x4,0 NYM-J, which as you state I have the capacity so will go with the twin separate utilities to the plugs etc on the 4mm cable and have the two circuits. The 1.5mm was fine but the 3x2,5 as it was labeled ended up being 5x2,5 - such a waste I don't need all that.

 

[securespark]

You probably don't need 1,5 either.

 

[spacey3]

You probably don't need 1,5 either.

Thats for lighting

 

[securespark]

So are you using 4 or 2.5 for sockets?

 

[spacey3]

So are you using 4 or 2.5 for sockets?

4mm for the sockets and items in the kitchen only, running 2 circuits one for the appliances and one for the remaining sockets.

The 2,5 is for the sockets in the remaining part of the house that we are moving and rewiring since the ceiling is down.

 

[securespark]

Thats for lighting

Oh, I see. They don't make 1 milli in that cable type.