8. Steel conduits and trunking are,
however, much heavier than single cables and, therefore, need substantial
and firm fixings and supports.4) and shown Table 14. Plasterboard cannot support screw fixing directly into itself
but the spring toggle spreads the load over larger area, making the fixing
suitable for light loads.
When heavier more robust fixing required support cabling or
equipment nut and bolt screw fixing called for.5. wide range support brackets available
for fixing conduit, trunking and tray installations the fabric commer-
cial industrial installation.
For lightweight fixings hollow partitions plasterboard spring toggle
can used.32. con-
duit installation can rewired easily altered any time and this flexibil-
ity, coupled with mechanical protection, makes conduit installations popular
for commercial and industrial applications.
Let look little more detail individual joining, support and fixing
methods.
FIGURE 14.The conduit, effect, replaces the PVC outer sheath of
a cable, providing mechanical protection for the insulated conductors.Basic Electrical Installation Work
320
masonry nail which means that the cables can fixed wood, plaster or
brick with almost equal ease.
A commercial industrial installation might call for conduit trunking
wiring system. Some these are shown Fig. Wood screws may be
screwed directly into wood but when fixing stone, brick concrete is
first necessary drill hole the masonry material which then plugged
with material (usually plastic) which screw can secured.
Cables must run straight and neatly between clips fixed equal distances
and providing adequate support for the cable that does not become
damaged its own weight (IEE Regulation 522. conduit tube, channel pipe which insulated con-
ductors are contained.
For the most robust fixing masonry materials expansion bolt such as
that made Rawlbolt should used.32
Same manufactured girder supports for electrical equipment. 14.
