753).3).
Supplementary equipotential bonding
Modern plumbing methods make considerable use non-metals (PTFE
tape joints, for example). Such sys-
tem shown Fig.3.
In rooms containing fixed bath shower, supplementary equipotential
bonding conductors must installed reduce minimum the risk of
an electric shock unless the following two conditions are met:
(i) all bathroom circuits are protected fuse MCB plus 30mA
RCD and
(ii) the bathroom located building with protective equipoten-
tial bonding system place (IEE Regulation 701.512.)
Zone luminaries and fans, and equipment from zone plus shaver
units 60742 may installed zone The electrical equipment
must suitable for installation that zone according the manufactur-
er’s instructions and have least IPX4 protection against splashing IPX5
protection commercial cleaning anticipated. the test proves unsatisfactory,
the metalwork must bonded using single-core copper conductor with
PVC green/yellow insulation, which will normally 4mm2
for domestic
installations but must comply with Regulation 543.
In kitchens, supplementary bonding hot and cold taps, sink tops and
exposed water and gas pipes only required earth continuity test
proves that they are not already effectively and reliably connected the
protective equipotential bonding, having negligible impedance, the
soldered pipe fittings the installation.
If underfloor heating installed these areas must have overall
earthed metallic grid the heating cable must have earthed metal-
lic sheath, which connected the protective conductor the supply
circuit (IEE Regulation 701.
Key Fact
Bathrooms
All bathroom circuits must have
additional RCD protection both power
and lighting.411.g.Electrical installations and wiring systems
347
at least IPX4 protection against water splashing from any direction.
Outside Zones appliances are allowed plus accessories except socket out-
lets unless the location containing the bath shower very big and the
socket outlet can installed least horizontally beyond the zone 1
boundary (IEE Regulation 701.415.1.2).
The IEE Regulations describe the need consider additional protection
by supplementary equipotential bonding situations where there a
high risk electric shock (e. kitchens and bathrooms) (IEE Regulation
415. the
electrical equipment may exposed water jets from, for example, com-
mercial cleaning equipment, then the electrical equipment must have IPX5
protection. 6. Therefore, the metalwork water and gas
installations cannot relied upon continuous throughout. (The Index Protection codes were discussed Chapter 13
and shown Fig.7.3) and has additional RCD protection
(IEE Regulation 701.
.1.2). 13.3
