Cable size equivalents (novice content)

[daveyclayton]

Hi,
I'm doing some work on my flat (in Germany) and have a novice electrical question. My intention, while I have the ceilings down, is to put in a suitable cable from the CU to a room at the far end of the building, which I may in the future want to make into an ensuite, and put an electric shower in.

The run will be about 20m. Obviously since I don't yet have a spec for a shower, I can't really do an accurate cable calculation, but it was my intention to put 10mm cable in, and if and when we come to have a shower fitted, to use an lower powered shower and appropriate MCB.

However, I'm finding it hard to get hold of 10mm twin and earth cable out here. What I can find, in all the builders merchants, is NYM-J 5x6mm. The question is, can I stick that in instead of 10mm? To my untrained brain it stands to reason that 5x6 will give a cable size of 12mm - is there anything I'm missing?

Cheers,
Davey

 

[MalcofArabia]

Yes nym-J cable is ok to use though it is normally used for commercial or industrial purposes.

I gather your plan is use 2 conductors for the Lives to make 12mm and the single 6mm yellow and green for the earth.

Obviously you will need to make sure by test that the 6mm CPC will be ok regarding disconnection times etc.

It's not unknown in the UK to parallel conductors like this, there is even a section in the regs for it, mainly deals with larger cables. but it's not normally seen as good practice, but not prohibited as such. Not sure about what the germans would think.

Also what colour are the conductors. if they are all black you may be ok. But if they are phase colours ie Brown, Black Grey and Blue in the UK you would need to sleeve them Brown and Blue. Again in Germany that may not be necessary

 

[PrenticeBoyofDerry]

Is this not for the use of industrial installations?
Your post would be more suited to the electrics outside the uk forum.

 

[ban-all-sheds]

Do Germans not have electric showers, or large cookers etc, in their houses?

Find it hard to believe that there's no 10mm² cable made for domestic use.

However, I'm finding it hard to get hold of 10mm twin and earth cable out here.

Can you get any twin & earth cable out there? I thought we were the only country in Europe to allow reduced size cpcs?

What does VDE-100 have to say on the matter?

 

[1john]

I assumed they used conduits and singles for hard wored circuits too. You could take some twin and earth with you although I dunno what the german insurance would say about that if a problem arrived. cant you have a mixer shower instead?

 

[ban-all-sheds]

You could take some twin and earth with you although I dunno what the german insurance would say about that if a problem arrived.

Probably something involving the word "verboten"

But it's really very simple for Davey to resolve. Look and see what VDE-100 says must be used.

If he cannot or will not do that then he has no business doing the work.

 

[daveyclayton]

Thanks for the replies,

Apologies, I meant NYM-J 3x10, not 10mm twin and earth(!). None of the main builders' merchants in Cologne stock it. I'll have a look at the DIN, I know that NYM is OK for my general installation circumstances, the question was really about doubling up on the conductors. I take the point about earth, and appropriate insulation colours in a 5x6mm set-up though.

I can only find one person on ebay selling 3x10, and it's 11.36 a metre (I need 20), which will make it a very expensive job for something which potentially won't ever get used. Whereas 5x6 is about a third of the price.

We currently have an electric water heater which is connected via what looks like a 5x6 (two black, one brown, one blue and an earth) with only three conductors connected. I don't take this to be a good example though, given the overall state of the apartment's electrics.

I would much rather have a mixer shower, yes, but we'll already have one in the main bathroom, and I though the boiler would simply not manage supplying two at the same time. Maybe I'll speak to the people who fit the boiler about it and see if I can accomplish it off the boiler with thermostatic valves instead.

Cheers for your help,
D

 

[OwainDIYer]

Do Germans not have electric showers, or large cookers etc, in their houses?

Many continental countries use 3-phase lower current circuits where we have single-phase higher current circuits. 3-phase is more prevalent in houses than here.