Triton Spellbind shower tripping RCD

[333rocky333]

One thing I've often wondered is how you would actually do a shower with trunking coming down from the top, most showers i've seen have the hinge at the top and even those that don't I would imagine you would have a nightmare of a time getting an adequate seal.

suppose trunking down the wall and stop short, drill downwards into the wall to behind base, drill upwards behind base
Cable down trunking into wall and into shower through back of base.
Would not do it personally.
Look c**p
If the tiles are hard as previously said, I would think about removing grout and trying to perhaps prise them off

 

[Softus]

One thing I've often wondered is how you would actually do a shower with trunking coming down from the top

You just run the trunking down to a suitable point at the top of the unit.

most showers i've seen have the hinge at the top

Hinge? WTF?

...and even those that don't I would imagine you would have a nightmare of a time getting an adequate seal.

What kind of seal do you think you'd need for an area of the shower that generally stays dry? Notwithstanding that, you would just apply silicone sealant to any gaps to keep out the water.

 

[plugwash]

well at least the mira shower we have hinges open at the top. maybe that is a mira oddity I haven't looked at many other showers in enough detail.

I certainly wouldn't expect the top of a shower unit to stay dry especially in a setup with a demountable head.

 

[Qedelec]

CB, regarding drawing in a new cable, a few tips.
Whenever possible, pull the cable up, not down, debris has a habit of dropping down and jamming the cable.
Strip enough insulation off both cables to allow you to bend back at least an inch, preferably 2.
Wrap tape around the join, making sure no conductor ends are poking out.
Have a mate who can follow instructions, helping you. One feeding other pulling.
Pray to the great god elektra for a smooth passage.

 

[cb1980]

Need to establish the route the cable takes from the shower to the isolation switch.

It goes down behind the tiles to under the bath. It then disappears behind the skirting board and presumably runs under the (tiled, heated) floor and out onto the landing where it's connected to the switch.

you have to ask yourself why the original installer did this

Personally, I think it was because he was an idiot. More generously, it could be that they accidentally bought a shower with too high a power rating after they had already tiled. In any case, he obviously wasn't able to self-certify the work...

That tape measure photo is at the CU.

I had a hunch that it was.

Yeah, I don't think too many people have a shower in the cellar. Although it would make the re-wiring easier...

OK. That certainly appears to be a DP (double pole) switch. We really really REALLY need to know the gauge of the cable on both the supply and load sides of that switch, since there's no guarantee that the cable isn't joined somewhere between CU and DP switch.

I should be able to get a photo of that up tonight.

Where would it go if you drilled through the back of the shower

Next door's bathroom, unfortunately. Nice thinking though.

CB, regarding drawing in a new cable, a few tips.

I'll get an electrician in to do the actual work (because I want it certified this time and anyway it involves touching the CU). Just trying to suss out the alternatives before I call one in and they insist on defacing my nice bathroom.

Thanks guys, photos will follow tonight hopefully.

 

[tnarg999]

CB - Not wanting to state the obvious, but make sure you flip off that 50A breaker at the CU before taking the cover off the isolation switch.. The supply side of that DP switch stays live even when the red switch is in the off position.

So the shower is actually over a bath, rather than in a shower enclosure? This means you have space under the bath hidden by a panel?

Check what kind of wall is behind the shower - it might, with luck, be a stud partition that you could literally drop a new 10mm cable down. Worse case would be if the existing cable is plastered in..

Can you remove the skirting board to take a look without damaging the heated floor? You might get lucky and find some trunking that conceals the cable..

 

[cb1980]

OK. That certainly appears to be a DP (double pole) switch. We really really REALLY need to know the gauge of the cable on both the supply and load sides of that switch, since there's no guarantee that the cable isn't joined somewhere between CU and DP switch.

DP switch, innards.

So the shower is actually over a bath, rather than in a shower enclosure? This means you have space under the bath hidden by a panel?

Yip, take a look...

general setup

under bath

Check what kind of wall is behind the shower

That'll be a plastered brick wall.

Oh, and FYI chaps, looks like it's 6mm² all the way to the shower. Don't know why I didn't think to show you this bit before...

Ta

 

[333rocky333]

DP switch, innards.

Are the reds same size

 

[cb1980]

DP switch, innards.

Are the reds same size

I'd say so.

 

[333rocky333]

DP switch, innards.

Are the reds same size

I'd say so.

Forgot
Do they look the same as IN the shower terminal
From the pic it looks smaller in the shower

 

[cb1980]

Forgot
Do they look the same as IN the shower terminal
From the pic it looks smaller in the shower

These wires are small... those wires are far away.

Sorry, couldn't resist!

I'm really grateful for your help.

I *think* they're the same size, but I don't have time to unscrew the shower cover again tonight to check.

 

[333rocky333]

Thoese incoming (old colour) conductors don't look anywhere near big enough to me. More like 2.5 mm² than anything else.

 

[securespark]

Granted the cable is undersized, but how could a 41.3A shower melt 6mm² cable, rated at a maximum of 46A?

It could happen in the extreme of adverse conditions, i.e. in conduit under/behind thermal insulation.

You missed what I wrote in brackets...

 

[tnarg999]

It does look like you have 6mm sq going from under the bath to the shower, shown by the size of the cable you have measured (approx 14mm wide). What puzzles me is that if you download the pic of the shower with cover off and zoom in, the cores of the cables coming in look to be single stranded rather than multiple stranded, and I didn't think 6mm T&E was single stranded?

Also the core of the cable going into the shower (grey on right) is poking out of the terminal a fair bit showing the copper. Worth checking it is pushed in fully to the terminal and done up tightly. A loose cable could overheat, don't know about tripping the switch though.

Has anyone else noticed the CPC from the DP switch is green/yellow sheathed copper, yet at the shower it is a thin brown insulated cable?.. perchance there is a join?


Did the same guy also install the jacuzzi pump and leave all his mess behind?

 

[333rocky333]

Has anyone else noticed the CPC from the DP switch is green/yellow sheathed copper, yet at the shower it is a thin brown insulated cable?.. perchance there is a join?

Is that not just bare discoloured copper with no earth sleeving

Possibly 6mm/ 2.5 joint behind the tiles