Electrical installations and wiring systems
317
It should remembered that when several cables are grouped together
the current rating will reduced according the correction factors given
in Appendix (Table 4C1) the IEE Regulations.
protection and permitting laid directly the ground ducts, or
it may fixed directly laid cable tray. Figure 6.
MI Cable installations
Mineral insulated cables are available for general wiring as:
● light-duty cables for voltages 600V and sizes from 1.
The cable easy handle during installation, pliable and may bent
to radius eight times the cable diameter. The PVC insulation would be
damaged installed ambient temperatures over 70°C below 0°C, but
once installed the cable can operate low temperatures.
The cable terminated with simple gland which compresses compres-
sion ring the steel wire armouring provide the earth continuity
between the switchgear and the cable.0 to
10mm2
,
● heavy-duty cables for voltages 1000V and sizes from 1.
. 126) shows cable and termination.
Site-made
bends
A
Factory-made
90° bend
B
FIGURE 14.
Figure 6. The
cable sheath provides sufficient mechanical protection for all but the most
severe situations, where may necessary steel sheath conduit
over the cable give extra protection, particularly near floor level some
industrial situations.0 to
150mm2
.31
Cable tray with bends.
The cables are available with bare sheaths with PVC oversheath.3 (p.2 shows PVC/SWA
cable
