Advice for electric shower feed

[Roger]

Ok lets pick you brains on this one.

Need to run a electric shower upstairs,would use 10mm T&E.Its a 3 bed semi and the customer suggested lifting a few boards and running down the cavity ! it has poly balls insulation which i understand will create problems with cables and cause them to crack over a period of time.
The consumer unit is sitted more than 3 meters away from the meter and incoming supply.This is in a service box on the outside of the property.Current CU is fully populated so I thought about splitting meter tails in service box ,putting a RCD/RCCB unit in and running cable in conduit up outside of building.Drill through outside wall and then just feed under floor boards.
Is this ok ? any thoughts ? suggestions ?

The whole house is finished to a high standard with built in units all over the place and every bit of space is full.
I gave a ball part figure which I thought was high so hoping they would say no,but they said yes !!!!
Its a pain of a job and i do not really need it at the moment so hopefully I will just keep saying I am to busy and he will just go away.

 

[IQ Electrical]

The whole house is finished to a high standard with built in units all over the place and every bit of space is full.
I gave a ball part figure which I thought was high so hoping they would say no,but they said yes !!!!
Its a pain of a job and i do not really need it at the moment so hopefully I will just keep saying I am to busy and he will just go away.

I don't see anything wrong with your proposal but of course he won't 'go away' -he wants a shower installing!
You should tell him you're too busy, then he can give the work to someone that wants/needs it.

 

[telectrix]

sounds good to me. hope you just forgot to mention the MCB in with your RCD. Do you need 10mm? 6mm is OK for up to 9.5kWas long as the cable run does not exceed 20m. say this because it's a pain to terminate 10mm in a switch/isolator designed for 6mm

 

[Roger]

Cheers Guys,the wholesalers do a nice little 2 pole RCCB in an enclosure which is perfect.To be honest I always do showers in 10mm as people always want to put the largest one going and at least i know it will take the load,overkill I know.

And your right IQ he won't go away ,I tried to fob him off saying could not do for a couple of months and he said no problem before christmas would be fine !!!!!

Cheers Guys

 

[telectrix]

cable in pvc conduit outside is fine if it's ok with client. i would continue the conduit thru the cavity wall as well, protect cable from chafing and insulation. just need to ask if he prefers black or white conduit. ( or can you only get it now in grey or brown? )

 

[Ponty Massive]

Bit of a thread creep here....I'm doing a simular job tomorrow but coming up the outside wall in SWA into the loft. Gonna be using 6mm SWA terminating into 10mm T+E. Was gonna terminate the SWA into a 4" adaptable box in the loft, but whats the best way to join it to the PVC? Possibly din rail and connectors? What about taking the 10mm T+E into the box (securing the cable etc).

Thanks all

 

[nickblake]

go with 10 mm especially if its running through a loft in contact with loft insulation try and glip it ablve if you can , the current carrying capacity is drastically reduced when in contact or covered with loft insulation 6 mm is only rated at 34 amps if its covered with less than 100mm insulation clipped direct its 47 and more than 100 mm of insulation its only 27 amps so id go for the 10mm

 

[malcolmsanford]

Why are you using 6mm^ armoured, what rating is the shower. 6mm^ in free air horizontal or vertical will give you 53amps. while that 10mm^ can give you as much as 63amp clipped direct.

 

[Roger]

Armoured up the outside now there a thought that might be easier.Terminate in loft in a 60 amp junction box.

That might be easier,i will go back and have another look this week.

Cheers

 

[Ponty Massive]

Shower is 10.5 Kw so using 45a as a guide. 6mm SWA allows for 49A then inside the loft using 10mm. 6mm T+E allows for 45A but will use 10mm as I feel this is too close to the limit for a loft.

 

[telectrix]

see your point, nick. i keep forgetting about the sh17 in the loft that should have been banned years ago.

 

[malcolmsanford]

Shower is 10.5 Kw so using 45a as a guide. 6mm SWA allows for 49A then inside the loft using 10mm. 6mm T+E allows for 45A but will use 10mm as I feel this is too close to the limit for a loft.

It's ok mate it's just me ...............as an ole git just don't like a smaller CSA going downstream

 

[nickblake]

see your point, nick. i keep forgetting about the sh17 in the loft that should have been banned years ago.

oh how i wish hate the stuff

 

[Ponty Massive]

It's ok mate it's just me ...............as an ole git just don't like a smaller CSA going downstream

I agree, don't normally like changing csa mid circuit, but if the regs allow then it'll do for me.

Was thinking of just using a 60a JB but what about glanding the SWA in the loft?

 

[malcolmsanford]

Have you thought about Hi-tuf

 

[telectrix]

I agree, don't normally like changing csa mid circuit, but if the regs allow then it'll do for me.

Was thinking of just using a 60a JB but what about glanding the SWA in the loft?

adaptable box in loft, gland SWA. Stuffing gland for T/E

 

[Ponty Massive]

Would it be exceptable to terminate SWA in the loft into a through box and dropping straight into the 45A isolator, just thinking less connections?

Will earth the SWA in an adaptable box at the CU end?

 

[nickblake]

adaptable box in loft, gland SWA. Stuffing gland for T/E

my garage supply i did a 10mm to a 25mm galv u box then 10 mm swa to garage swa gland and stuffing gland works a treat

 

[Ponty Massive]

I think though to keep connections to a minimum, may just terminate armourings into a galv through box in the loft just above the pull cord isolator, continue the inner sheathed cable straight out the other end and through a stuffer, clip it to the joists and then drop down into the isolator, 6mm SWA in then 10mm T+E out and to the shower.

What's youir thoughts?

 

[m25maintenance]

use 1.5 t+e like one of my customers done last month. lmbo