8.
The necessary skills can acquired electrical trainee who has the
correct attitude and dedication his craft.1).1.5.3 and Table the Site Guide).6.21 shows typical PVC installation. Cables should run horizontally vertically, not diagonally,
down wall. PVC cables not react chemically with plaster,
as some cables, and consequently PVC cables may buried under plas-
ter. All kinks should removed that the cable run straight
and neatly between clips fixed equal distances providing adequate sup-
port for the cable that does not become damaged its own weight
(Regulation 522. also
assuming that the surrounding temperature throughout the length the
circuit does not exceed 30°C and the cables are run singly and clipped to
a surface. The
cables are generally fixed using plastic clips incorporating masonry nail,
which means the cables can fixed wood, plaster brick with almost
equal ease.6. Where cables are bent, the radius
of the bend should not cause the conductors damaged (Regulation
522. However, Regulation 522.6.6 tells that outside a
zone formed 150mm border all around wall edge, cables can only be
.
Wiring systems and enclosures
The final choice wiring system must rest with those designing the
installation and those ordering the work, but whatever system employed,
good workmanship competent persons and the use proper materials
is essential for compliance with the Regulations (IEE Regulation 134. Table the IEE
On Site Guide shown Table 14. Mechanical damage to
the cable caused impact, abrasion, penetration, compression ten-
sion must minimized during installation (Regulation 522. identify
the most probable cable routes, Regulation 522. Further protection channel conduit only necessary mechani-
cal protection from nails screws required protect them from the
plasterer’s trowel.4 and Table the Site Guide).
Terminations joints the cable may made ceiling roses, junction
boxes, behind sockets switches, provided that they are enclosed a
non-ignitable material, are properly insulated and are mechanically and
electrically secure (IEE Regulation 526). All joints must accessible for
inspection testing and maintenance when the installation completed
(IEE Regulation 526.8.6 now tells that where
PVC cables are embedded wall partition depth less
than 50mm they should run along one the permitted routes shown
in Fig.3).
PVC insulated and sheathed cable installations
PVC insulated and sheathed wiring systems are used extensively for light-
ing and socket installations domestic dwellings.
Where PVC insulated and sheathed cables are concealed walls, floors or
partitions, they must provided with box incorporating earth termi-
nal each outlet position.Electrical installations and wiring systems
303
thermosetting cable with LSF (low smoke and fume properties).22.1). 14. Figure 14
