On May 14, 7:35*am, " wrote:
On May 13, 4:35*pm, "Jake" wrote:

Some friends of mine live in a property with an ancient shower. The power
cable runs from the ceiling along the tiled wall to the top of the shower.
Presumably this was permitted in previous installations?

The shower is now out of order, and it is likely a new shower will be
required. Is it still permitted to leave the cable in this position, or
should it be buried in the wall?

Unprotected surface wiring, not OK - and hasn't been for a long time
AFAIK.

Also sounds like it's flexible cable, rather than solid core.

If it's surface, should be in trunking.

Given it's potentially the most hazardous electrical installation in
the home, I'd prefer to see a single piece of cable, no joins, running
from the CU (with RCD/RCBO), to right inside the shower unit, with no
possibility of fingers or moisture getting near the cable or its
connections.

1. I read the OP as saying cooker cable and from the normal
expectation this would be 6mm or greater twin and earth with an
oversheath of PVC. This may not be as "pretty" exposed to view as a
bit of trunking.
2. Which regulation do you allege prohibits the use of such sheathed
cable in the circumstances or did you make that up? Flat thermoplastic
insulated and sheathed cable (undamaged) is suitable for use both
outdoor and indoors in dry or damp locations.
3. For an unbroken length of cable from the CU where are you thinking
of providing the local double pole isolator?

The like for like swap of an old shower for one of similar rating is a
simple minor works job, however it would be eminently sensible to
provide an RCD at the consumer unit or next to it if the CU is not
suitable for modification. Don't forget also that satisfactory result
of an Earth Fault Loop Impedance test is one of the essential checks
for even minor works,
Note that many shower manufacturers now specify the provision of an
RCD in their installation instructions.