5 22
2. 4.7, 20mm conduit, long and containing one bend, has factor 233.
c
ctors
6 30
180
From Table 14.
Example 2
Ten 1.Electrical installations and wiring systems
309
Table 14. Determine the minimum size conduit contain these cables.
Determine the minimum size conduit contain these conductors.
.
From Table 14.
Example 1
Six 2.5mm2
PVC insulated cables are run conduit containing two bends between
boxes 10m apart.0mm2
PVC insulated cables are drawn into plastic conduit which long
between boxes and contains one bend. A
16mm conduit containing one bend only has factor 143 which less than 203, the sum of
the cable factors and, therefore, 20mm conduit the minimum size contain these cables.6 Conduit Cable Factors.
.5 times
the outside diameter the conduit.7, 25mm conduit, 10m long and containing two bends, has factor 260.0mm PVC insulated CPC also included.6:
The factor for one cable
The factor for one m
1 16
4 0
.
m
m cable
The sum the cable factors )
43
10 43
203
(
From Table 14. A
20mm conduit containing two bends only has factor 141 which less than 180, the sum
of the cable factors and, therefore, 25mm conduit the minimum size contain these cables.
From Table 14.6:
The factor for one cable
The sum the cable fa
2 30
2
.5 30
4 43
6 58
10 105
16 145
25 217
The inner radius conduit bend should not less than 2. Adapted from the
IEE Site Guide Kind Permission the Institution of
Electrical Engineers
Cable factors for use conduit long straight runs over 3m,
or runs any length incorporating bends
Type conductor Conductor cross-
sectional area (mm2
)
Cable factor
Solid stranded 16
1
