Power shower wiring

[ColinJohnston]

Hi all,

I understand the wiring requirements for Electric showers that need 10mm2 cable.

I'm just not clear of the position with Power showers, specifically this Mira one:

http://www.mirashowers.co.uk/onlinecatalog/pdf/1079321_w2_d_mira_go_thermostatic_power_shower.pdf

The Mira spec says 1.0mm2 to 2.5mm2, basically the same stuff as used for sockets around the house.

Good old google has thrown up links that suggest it can be wired as a spur from existing wiring.

Can anyone clarify what this one actually needs?

Many thanks

 

[Marvo]

Power supply - 230-240 V at 50 Hz, fused at 3 Amps, via a double pole fused switch (not supplied) with a minimum contact separation of 3 mm for each contact.

Electrical Connections - Terminal block will accept cable up to 2.5 mm². Minimum cable size (cross-sectional area) required under normal installation conditions is 1 mm2.

Power Consumption - 150 W maximum.

The instructions are pretty specific, I'd suggest rather follow them than arbitrary internet advice.

 

[shanky887614]

Hi all,

I understand the wiring requirements for Electric showers that need 10mm2 cable.

I'm just not clear of the position with Power showers, specifically this Mira one:

http://www.mirashowers.co.uk/onlinecatalog/pdf/1079321_w2_d_mira_go_thermostatic_power_shower.pdf

The Mira spec says 1.0mm2 to 2.5mm2, basically the same stuff as used for sockets around the house.

Good old google has thrown up links that suggest it can be wired as a spur from existing wiring.

Can anyone clarify what this one actually needs?

Many thanks

if its fed from a boiler it will probably only need 2.5mm (hot and cold)

10mm is if the shower only takes a cold water feed

 

[alanl]

It is a 150 watt appliance.
1.5mm T+E is fine, they use a 3 Amp fuse, so in theory could use 1mm, but being as it is a power use, we have to use 1.5mm.
Without looking up the instructions linked above, the one I did last week said it MUST have RCD protection.
We only have to take note of Manufacturers Instrcutions now, but disregarding that one in Court would be very difficult, so make sure it has RCD protection.

 

[shanky887614]

It is a 150 watt appliance.
1.5mm T+E is fine, they use a 3 Amp fuse, so in theory could use 1mm, but being as it is a power use, we have to use 1.5mm.
Without looking up the instructions linked above, the one I did last week said it MUST have RCD protection.
We only have to take note of Manufacturers Instrcutions now, but disregarding that one in Court would be very difficult, so make sure it has RCD protection.

the thing is the op has to follow it as he cant use his electrical knowledge and experience to not follow them.


if it gets taken to court he will be ripped to shreds if he doesnt follow the manufacturer's instructions or bs7671 which i doubt he owns

 

[richy3333]

Am I missing something, won't it need RCD protection anyway being a special location?

 

[shanky887614]

Am I missing something, won't it need RCD protection anyway being a special location?

yes it will

 

[ColinJohnston]

Many thanks for the clarity. So, if I go down the route of a 30ma RCBO, what size of fuse rating would it need? (isolating switch would still be fused at 3amps as per manuf. instr.)

 

[Hellmooth]

Could use an rcd fcu?

 

[Guest77]

Come on Marv, this really should be in the DIY forum,.

 

[GMES]

Thread moved to diy on account of op being a Joiner according to his profile.

 

[markc123]

Hi all,

I understand the wiring requirements for Electric showers that need 10mm2 cable.

I'm just not clear of the position with Power showers, specifically this Mira one:

http://www.mirashowers.co.uk/onlinecatalog/pdf/1079321_w2_d_mira_go_thermostatic_power_shower.pdf

The Mira spec says 1.0mm2 to 2.5mm2, basically the same stuff as used for sockets around the house.

Good old google has thrown up links that suggest it can be wired as a spur from existing wiring.

Can anyone clarify what this one actually needs?

Many thanks

Umm, i hope not ...

Also ... table 52.3 BS7671 minimum CSA for power circuits = 1.5mm

I know you're supposed to follow manufactures instructions - but it would be nice if the manufactures actually consulted the regs them selves on occasions and got themselves at least a little bit in sink.

 

[ColinJohnston]

Thanks for all of the replies, think I'm sorted on the setup now with the exception of the bonding...
Seems like everything that is currently in the bathroom is bonded, and I will be able to extend the bonding to the copper feed pipes leading to the shower.
However, not sure about bonding the actual shower unit itself. Do I need to bond it too, and if so, where to connect the bonding wire to?

 

[telectrix]

Thanks for all of the replies, think I'm sorted on the setup now with the exception of the bonding...
Seems like everything that is currently in the bathroom is bonded, and I will be able to extend the bonding to the copper feed pipes leading to the shower.
However, not sure about bonding the actual shower unit itself. Do I need to bond it too, and if so, where to connect the bonding wire to?

these pipes need to be tested to see if they are (a) already bonded . (b) do they require bonding.