Using 2x2.5mm cables to make a 5mm cable?

[Multiplex]

Hi,

I´m in Germany doing some renovating and we´re installing an instant hot water heater that is using 4.6kw of electricity.

When we went to the local shed they didn´t seem to sell any cables bigger than 2.5mm. My German friend said "no problem" let´s use two 2.5mm cables and then we have a 5mm cable.

Is this a stupid idea, are there any potential problems when doing this?

Thanks,

Simon.

 

[andypee]

It would work but does leave you open to possible future problems and you certainly would not get away with it if an english electrical inspector found it so I doubt a German one will be much more forgiving. I doubt very much you can only get 2.5mm sounds like a shabby wholesalers.
What do they do when they need a bit of 16mm t+e? Run seven 2.5mm's?

 

[Pensdown]

It would work but does leave you open to possible future problems and you certainly would not get away with it if an english electrical inspector found it so I doubt a German one will be much more forgiving. I doubt very much you can only get 2.5mm sounds like a shabby wholesalers.
What do they do when they need a bit of 16mm t+e? Run seven 2.5mm's?

Whats wrong with cables in parallel?

 

[ban-all-sheds]

you certainly would not get away with it if an english electrical inspector found it

Errr....

473-01-06, 07, 08
473-02-05
523-02-01

 

[crystal ball]

I've installed parallel cables plenty of times, mainly to make installation easier, 2x 240mm is easier than 1x400mm when terminating into a shoebox sized cubicle

 

[Softus]

you certainly would not get away with it if an english electrical inspector found it

Pardon my potential ignorance (no pun intended), but isn't this just a very sparsely populated ring final circuit?

 

[Spark123]

Sounds like a similar idea as the ring main with all loading at mid point, it is two cables in parallel. As long as the cable length and csa are the same (so resistances of the cables are equal), both cables will share equal current. Afaik it is acceptable to the iee regs, I don't have a clue wether or not the German wiring regs allow this.

 

[Adam_151]

I don't have a clue wether or not the German wiring regs allow this.

Anyone seen mapj1 around this forum lately? He still posts over at IEE but haven't noticed him around these parts lately

 

[PompeySparks]

It is common practice for large submains to be wired in parallel as smaller cables are easier to install than one huge one!. For final circuits in a domestic setting this method should not be used. BAS has highlighted some relevant regs - as well as those it just makes the wiring more messy and fault finding a far more drawn out process!

 

[Multiplex]

Thanks for all the replies. In this case i think I´ll just let him get on with it if it isn´t dangerous.

This is a German flat built in 1959 and I´m really surprised with the electrics. All the sockets are connected with two wire 1.5mm cable which is fixed to the wall with a nail in the middle of the cable! The earth and the neutral unfortunately are shared and connected by a small piece of wire in each socket and light switch.

I think the reason why the sheds don´t stock anything more than 2.5mm is because when the Germans wire up their water heaters/showers/ovens they use 400v three phase for these appliances. Hence no need for big cables.

Thanks,
Simon.

 

[plugwash]

indeed have you checked your incomer arrangements? small 3 phase supplies are far more common in continental europe than they are here!