On Monday, 4 September 2017 10:22:49 UTC+1, John Rumm wrote:
On 04/09/2017 08:31, wrote:

Thanks all. Especially for the shaver socket tip. I had previously
assumed the only difference between them and sockets was dual voltage


Note that there are two types of shaver socket. The transformer based
ones that are suitable for bathrooms (and usually offer dual voltage)
and the non transformer based ones that are not suitable for bathrooms.

The shaver socket on the wall would work best but we have a small
splashback and then huge mirror above the sinks so only place would
be between the sinks and just off worktop level which seems a bit
dodgy to me? So...

Looks like best option is shaver sockets in the cupboard below the
sinks.

Another option is a shaver socket built into an over mirror based light
fitting.

In terms of the spa bath then I guess running a feed to the cupboard
and installing a ipx4 or better switch to switch it off (or maybe one
of those dual pole things that we use to isolate the extractor fan)
and then run this to the bath with a waterproof junction box under
the bath for extra safety.

Sound ok?

Yup you can have a remote switch for the bath feed if you want. You
could place the switched fused connection unit in the cupboard, and then
have that feed either a junction box or flex outlet the bath if you want.

So... Last 2 questions. 1. The bath has the metal framing connected
to one of the motors via an earth lead. However the earth from the
mains connection doesn't seem to be connected to it. I would have
expected to see an earth coming out of the junction box to connect to
the frame. Any thoughts?

I am not totally clear on exactly what setup you have here, so I will
answer the more general questions...

If the motor units are double insulated (has the double square logo[1])
then they do not need an earth connection. However you would normally
wire the connection point such that one is available in case the motor
were changed later and the new one needed one. If needs be, the earth
connection can be made of in a spare non connected terminal block.

[1] http://wiki.diyfaq.org.uk/index.php/...l_Glossary#1-9

If the motors do require an earth, then the earth of the circuit feeding
them should be included into the supplementary bonding in the bathroom.

The metal frame of the bath itself is typically not connected to
anything outside of the room itself, and hence not capable of
introducing any potential into the room. As a result it does not need
including in the EQ bonding.

See http://wiki.diyfaq.org.uk/index.php/...ng_and_Bonding

2. I plan to cut into the upstairs ring main
to feed this bathroom. Not a spur buy essentially extending the ring.
Any issues with this?

No that's fine. Note the comments above about including its earth in the
bonding for the room.

Connecting the bath frame to the motor frame does make it able to introduce 240v in case of fault. I would earth it & feed it from an RCD or include it in equipotential bonding.


NT