Fitting shower?

[MrTrance]

Hi, im fitting a shower for my mum in 10mm twin and earth, I have already got an mcb on the rcd side (40A). I am going ot get a 45a double pole isolator switch.

Is this correct?

CU - [SUPPLY-ISOLATOR] - [FEED-ISOLATOR] - SHOWER

Also will the plumbing work (also DIY), will the pipe from the cold water pipe have to be copper because if its plastic it will need to be bonded won't it?

10mm seems to be a ball ache to cut etc, any tips on terminating etc, looks like its going to be tight getting the cable from the loft to the CU (downstairs)?

Also on the isolator shall I just mount it with a 45mm back box in my bathroom next to the light pull switch? Then put a hole through the backbox and leave the cable dangling vertical so it doesnt bend in the back box when secured?

Hope this makes sense, im only 16, my college tutor is coming out to test it once complete,

 

[Des 56]

For anybody being schooled there is good reason to extend yourself with the subject,however, before you continue you need to be aware of a few things that come to mind

Being a student of electrics you are made aware that incorrect installation can result in injury fire or death,so take the time to be absolutely confident of what you are doing before you attempt this job

A bathroom as you may know is considered a special location and with good reason,coming into contact with electricity whilst possibly being wet or with bare feet makes the location a very potentially dangerous place

If you are doing this as a college task then perhaps the tutor needs to make you aware of other obligations

Working on electrics in a special location is notafiable to building control before you commence the work or a high fine is possinble or jail if someone is injured

As for the actual work The isolator you are intending to fit It implies a pull cord but doesn't actually state that
Be sure that the position of the pull cord is in the correct zone
The wiring is cons unit to isolator supply side and isolator load side to the shower
Be also aware that the earthing and bonding of the installation is adequate If not this has to be installed before the addition can be made for good reason
If you have an rcd then as long as the exposed pipework in the bathroom meets 4 criteria then it can be ommited, otherwise supplementary bonding has to be carried out
You are using 10mm for the shower, was this size plucked out of the air or have the calculations been done for correct sizing

I think with the questions I have raised you need to think carefully about this job and maybe ask individual questions for each querie until you are sure of the installation method and procedures
regards Des

 

[MrTrance]

I am aware of the above lol, I might only be 16 but im not stupid.

Calculations were made and most showers are fitted with 6mm but this is a 9kw shower and 10mm as more current carrying capacity.

My tutor is lending me his tester and all bonding is fine, im T'ing off using metal pipes so no plastic will disrupt the equipotential bonding process, 30mA RCD is in place.

Time to start work.

 

[flukey]

I am aware of the above lol, I might only be 16 but im not stupid.

Calculations were made and most showers are fitted with 6mm but this is a 9kw shower and 10mm as more current carrying capacity.

My tutor is lending me his tester and all bonding is fine, im T'ing off using metal pipes so no plastic will disrupt the equipotential bonding process, 30mA RCD is in place.

Time to start work.

not before notifying your labc
your college tutor should have told you this

 

[MrTrance]

QUESTION 2:

Can I run the 10mm cable down by the chimney brest, there are 3 copper pipes going down this space (about 300x150mm), the pipes look like there lagged all the way up but im not 100% sure.

I am a bit worried about the heat (even though they are touchable), will the cable be ok? I can't follow the lighting cables because they are buried in the wall.

Cheers people.

 

[flukey]

QUESTION 2:

Can I run the 10mm cable down by the chimney brest, there are 3 copper pipes going down this space (about 300x150mm), the pipes look like there lagged all the way up but im not 100% sure.

I am a bit worried about the heat (even though they are touchable), will the cable be ok? I can't follow the lighting cables because they are buried in the wall.

Cheers people.

 

[Guest123]

Hello there.

I would say not. The cable will be working very hard as it is, supplying a 9KW shower (39A). The additional heat in that pipe boxing I feel will derate the cable to an extent where the CCC is reduced too much and you may end up with a molten mess!!!!

I suggest a seperate pvc trunking riser in the corner of a room somewhere discreet.

Hope this helps.

 

[MrTrance]

But how do I get this riser from top to bottom without making to much of a mess?

 

[Guest123]

I suggest a seperate pvc trunking riser in the corner of a room somewhere discreet.

Seems like this will be your only solution to avoid too much disruption to decor. Surface run in pvc mini trunking.

 

[adamh]

its either that or chase it in unless you can fish it down the wall cavity from the loft (only joking before every1 shouts at me)!!

 

[MrTrance]

Do you mean so the pvc is visible in front room and main bedroom?

its either that or chase it in unless you can fish it down the wall cavity from the loft (only joking before every1 shouts at me)!!

Thats what I was gonna do, whats wrong with it, just heat?

 

[adamh]

your not supposed to run cables with hot water pipes due to the heat exchange/derating factor simplest way is to run trunking in the corner of the room next to your pipe box out and you will never see it or chop it in but that means decorating whatever you do dont clip it down the outside of the house!! HTH

 

[MrTrance]

Looks like a pvc trunking job then.

 

[jeremy]

Trunking doesn't have to be square edged and noticable. D-line trunking is quadrant (quarter circle cross section) so is fairly un-noticable as it doesn't cast shadows. When it's run up the corner of a room and painted the same colour as the rest of the room, it really blends in. (This is not an advertisement for D-line, I just think it's a good product)