G
Gazzza
We removed an electric shower a year or so ago (don't know kW of it, long since binned) from an en-suite (now removed) that was in bedroom on the back of the house.
The circuit is still in, but not connected. The circuit is 6mm cable, and has a (currently disconnected) 32A MCB at the consumer unit. From this i'm assuming the old shower was 7 or 7.5kW. There was no RCD incidentally.
We're now doing the bathroom and want an electric shower in there. Problem is our water pressure is erratic and at peak times the old en-suite shower wouldn't work due to low pressure. Solution, triton or mira pumped electric shower fed from cold water tank. Problem - the mira is 9.8kW, and the smallest Triton do is 8.5kW.
The cable run, if i extended the exsiting circuit from where it is currently terminated, to the bathroom, would be approx 18.5 - 19 metres worst case. Routing from CU is between walls, behind skirting, and up to first floor against external wall boxed in behind plasterboard, then across under floorboards to the current point where it terminates below the old shower - im hopefull I can intercept it en-route under the bathroom (not yet removed old bath etc so can't get floorboards up yet to confirm), and knock some 6m off the run. But worst case is i'll have to extend from the existing termination point, meaning my run is say 20m in 6mm. I'd plan on adding 30mA RCD. All the reading i've done on here suggest 10mm is more suitable, but i've also read various places 6mm should be acceptable for 8.5kW.
The Triton 8.5kW pumped tech page says nominal power rating of 8.5kW at 240V and 7.9kW at 230V, and suggests a 40A MCB.
8.5kW at 240 would give me 35.42A which would seem within the limits of the 6mm. But frankly i don't want to take any risks. Whats the general view on this ?
Re-wiring internally, is not really practical, or more to the point cost prohibitive - all the rooms the wiring runs through behind walls etc are newly decorated, floors and walls tiled etc etc - the glorious benefit of hindsight eh.
I've another option if re-wiring is strongly recommended - CU is on an external wall. Can I run a new circuit out through the wall, then externally up to the loft space, back in and down into the bathroom, obviosuly avoding insulation in the loft etc ? Do regs allow this ?
Cable run would then be approx. 10m.
If this is possible, would i be as well going for 16mm giving me the option of higher kW shower now or in future.
Sorry i've waffled on a bit, but thanks for any advice, suggestions.
Cheers
G
The circuit is still in, but not connected. The circuit is 6mm cable, and has a (currently disconnected) 32A MCB at the consumer unit. From this i'm assuming the old shower was 7 or 7.5kW. There was no RCD incidentally.
We're now doing the bathroom and want an electric shower in there. Problem is our water pressure is erratic and at peak times the old en-suite shower wouldn't work due to low pressure. Solution, triton or mira pumped electric shower fed from cold water tank. Problem - the mira is 9.8kW, and the smallest Triton do is 8.5kW.
The cable run, if i extended the exsiting circuit from where it is currently terminated, to the bathroom, would be approx 18.5 - 19 metres worst case. Routing from CU is between walls, behind skirting, and up to first floor against external wall boxed in behind plasterboard, then across under floorboards to the current point where it terminates below the old shower - im hopefull I can intercept it en-route under the bathroom (not yet removed old bath etc so can't get floorboards up yet to confirm), and knock some 6m off the run. But worst case is i'll have to extend from the existing termination point, meaning my run is say 20m in 6mm. I'd plan on adding 30mA RCD. All the reading i've done on here suggest 10mm is more suitable, but i've also read various places 6mm should be acceptable for 8.5kW.
The Triton 8.5kW pumped tech page says nominal power rating of 8.5kW at 240V and 7.9kW at 230V, and suggests a 40A MCB.
8.5kW at 240 would give me 35.42A which would seem within the limits of the 6mm. But frankly i don't want to take any risks. Whats the general view on this ?
Re-wiring internally, is not really practical, or more to the point cost prohibitive - all the rooms the wiring runs through behind walls etc are newly decorated, floors and walls tiled etc etc - the glorious benefit of hindsight eh.
I've another option if re-wiring is strongly recommended - CU is on an external wall. Can I run a new circuit out through the wall, then externally up to the loft space, back in and down into the bathroom, obviosuly avoding insulation in the loft etc ? Do regs allow this ?
Cable run would then be approx. 10m.
If this is possible, would i be as well going for 16mm giving me the option of higher kW shower now or in future.
Sorry i've waffled on a bit, but thanks for any advice, suggestions.
Cheers
G
