Surface conduit

[Davidabcd]

Hello there,

I am considering surface conduit for my shower too.

Perhaps you could help me with a few newbie questions? As I would like to try to understand this before I commission an electrician.

1. How can trunking be preferable when one flexible conduit could get all the way from the shower to an isolation switch in the hall with zero joints for water to get in?

2. How can trunking be preferable when conduit could have a waterproof join to the shower case by using a gland?

(I'm assuming there is a round hole in the case for the wires to go in as the Triton T70Z online instructions say:
"The cable can be surface clipped, hidden or via 20mm conduit")

3. I agree with Coljack that conduit would look better in a bathroom beside pipes. My bathroom will have a horizontal run of pipes at waist height, surface mounted using 'Talon' screw-in plastic pipe clips. The clips join together so that the pipes are evenly spaced. The obvious way for me to route conduit is join on an extra clip and run the conduit parallel with the pipes. Does that sound acceptable?

Thanks,

David

 

[seasickstevie]

How long is the run?

Flexibly conduit surface run, and on show, is not going to look as tidy as your pipework.
Unless of course the pipes are plastic also. In which case it's all going to look a bit shoddy.

But maybe you like that

 

[SteNova]

surface mounted horizontal pipes??? is there no other way?

 

[Davidabcd]

Hi thanks for the responses. It's whether it meets the regulations I'm concerned about.

Another question has crossed my mind:

4. I understand the conduit needs a suitable IP rating for waterproofing, and there are requirements for distance of fixings, but is there also a standard of strength or crush-resistance it needs to meet?

Total run to consumer unit approx 14m. In bathroom approx 2.5m. Fully visible run in bathroom approx 1.2m.

As for the aesthetics, yes I'm loopy and chose to do it like this.

David

 

[londonboy]

The conduit needs no IP rating whatsoever.

You could clip the shower cable if you wanted.

The IP rating is for accessories and enclosures, IE the shower and the isolator.

 

[plugwash]

The conduit needs no IP rating whatsoever.

I'm not convinced of that, afaict T&E isn't designed for permanently sitting in water (which could happen if you aren't carefull about where water can get in and where it can get out) and the conduit could also carry water where it is not wanted.

 

[londonboy]

The conduit needs no IP rating whatsoever.

I'm not convinced of that, afaict T&E isn't designed for permanently sitting in water (which could happen if you aren't carefull about where water can get in and where it can get out) and the conduit could also carry water where it is not wanted.

As far as I can tell, in this instance, the OP is talking about running conduit internally in a bathroom.

Although externally I agree you should make joints tight and use drain holes.

 

[plugwash]

Afaict he is planning to install a shower, probablly one with a demountable shower head.

That means the conduit feeling it will almost certainly get sprayed from various directions.

 

[londonboy]

....

That means the conduit feeling it will almost certainly get sprayed from various directions.

Which is no different to using MT

 

[plugwash]

Indeed, IMO whatever you use you need to consider if water will be able to get in and if so if and where it will come out so that the contents dont end up sitting in stagnent water and the conduit/trunking doesn't end up carrying water places you dont want it.

 

[ban-all-sheds]

Perhaps the answer is to consider having the pipes and the cables buried in the wall.....

 

[londonboy]

Perhaps the answer is to consider having the pipes and the cables buried in the wall.....

I agree. I have a feeling this is a simple job thats being overcomplicated!

 

[Steve]

I used trunking in my bathroom, when we replaced the cable feeding the shower.

It ran from floor to ceiling close to the shower enclosure. Then it ran back down to the shower unit itself, where I made the joint using silicone. Water was able to drip into the shower casing (into the cable management area, where water is able to dissipate without geting to the connections).

 

[Davidabcd]

Hello thanks for the responses!

So the general message is think carefully about where water can get.

I have two more questions I need to know before I can specify the conduit:

5. I'm sorry, but elsewhere on this site I can't find this answer: Can someone definitively say whether an electric shower head is or isn't a 'low pressure jet' for the purposes of ingress protection?

6. Is this the correct sizing of the conduit: (dimensions taken from tlc direct website):

10mm2 twin and earth is 17.1mm x 10mm = 171mm2 cross sectional area.
25mm Electroflex Conduit has internal diam 20mm = 400mm2 cross sectional area.
45% of 400mm2 = 180mm. Therefore this conduit is sufficient.

Thanks

David

 

[ban-all-sheds]

25mm Electroflex Conduit has internal diam 20mm = 400mm2 cross sectional area.

I really don't think so.

Does πr² ring a bell?

45% of 400mm2 = 180mm. Therefore this conduit is sufficient.

1) No it's not.

2) Even if on paper a conduit size appears to be OK, good luck pulling 10mm² T/E through it.

3) Don't forget to allow for the bends when calculating your conduit factor.