Electrical wire for electric shower

[MalcolmS]

Hi All,
I hope you are doing well.
I am asking about the electrical wire. I am in the process of working on the floor across the 1st floor and while the decking is exposed I want to run a wire for future power shower. What wire should I use?
Thanks
Best regards

 

[newfutile]

Probably 6 or 10 mm however it’s not as simple as that, you need at least:
the power rating of intended shower, length of run for cabling, method of installation, thermal insulation affecting the cable , type and rating of the protective device.

 

[MalcolmS]

Cable would be about 8m in total
The power shower - standard 240V
The cable would run in the void under the floor
I have no idea about other things you mentioned

 

[brianmoooore]

Power shower or electric (heating) shower. Two completely different animals, and complete opposites.

 

[MalcolmS]

I think you nailed it, yes I made a mistake it's electric shower.

 

[brianmoooore]

Then exactly as newfutile's answer above, although it's fairly unlikely to be 6mm2 with the latest showers.

 

[pc1966]

For all the cost difference now versus having to replace later, put in 10mm cable and have a decent amount of slack at each end.

Somewhere along its route you will need an isolation switch so the shower can be switched off for any maintenance or if faulty, etc. Traditionally that was an adequately rated roof-mounted pull switch (e.g. Crabtree 50A type) but you can have a more conventional switch elsewhere so long as it is suitable for the environment as well as adequately rated.

For now just get the cable in and let any future spark worry about that aspect, but if you are planning building/decorating work then sorting out an expected switch position, etc, early on can save a bit of hassle.

 

[MJPD29]

Cable would be about 8m in total
The power shower - standard 240V
The cable would run in the void under the floor
I have no idea about other things you mentioned

Standard 240v is irrelevant. Power not voltage required

 

[MalcolmS]

For all the cost difference now versus having to replace later, put in 10mm cable and have a decent amount of slack at each end.

Somewhere along its route you will need an isolation switch so the shower can be switched off for any maintenance or if faulty, etc. Traditionally that was an adequately rated roof-mounted pull switch (e.g. Crabtree 50A type) but you can have a more conventional switch elsewhere so long as it is suitable for the environment as well as adequately rated.

For now just get the cable in and let any future spark worry about that aspect, but if you are planning building/decorating work then sorting out an expected switch position, etc, early on can save a bit of hassle.

Awesome. Thank you. I get the wire sorted in advance.

 

[Intoelectrics]

Just be careful how you run the cable, make sure its routed sensibly with no strain and if run with other cables make sure there is plenty of room and no damaged is caused when pulling in. Avoiding routes where it could be damaged by nails/screws and is not draped over or too close to metal pipe work. It may also require additional support depending on the intended though in most underfloor circumstances there is usually little if any required. Also beware of guidelines regarding drilling through floor joists.

There is guidance available on installation methods and cable routes. My advice would be to look this up before you plan your route.

 

[DPG]

Post #10 is great advice. You don't want to end up getting an electrician in to fit the shower in the future and him refusing to install it/sign it off because the cable routing doesn't meet regs.

 

[nicebutdim]

Post #10 is great advice. You don't want to end up getting an electrician in to fit the shower in the future and him refusing to install it/sign it off because the cable routing doesn't meet regs.

Or find that the particulars of this installation mean a relatively expensive length of cable is undersized.