The cable rating, given by:
I
I
t
n
Current rating protective device )
The product of
t
the correction factors
the correction factors included this calculation are:
Ca ambient temperature; from the table shown Table 14.93 0.4 3.
(mV/A/m)
Three- four-core
cable, three-phase
(mV/A/m)
1 4
1 38
1.42
.10
50 0.Electrical installations and wiring systems
301
Nominal current setting the protection for this load 32A.
(mV/A/m)
Two-core cable,
single-phase a. Adapted from the IEE site
Guide Kind Permission the Institution Electrical Engineers
Table 4D1B IEE Regulations
Voltage drop (per ampere per metre) Conductor operat-
ing temperature:
70°C
Conductor
cross-sectional
area (mm2
)
Two-core
cable, d.
Cg grouping factors need not applied.56
95 0.4
r r
25 1.3 Voltage Drop Cables Factor.63 0.95 0.04 A
t
I
32
0 94
.46 0.5
6 7.4 4.4
10 4.
From column the table shown Table 14.81
70 0.49 0.25 1.
The design current 26.30 1.
Ci thermal insulation demands that assume installed method (see Table 14.2).
Table 14.
Cc since protection MCB factor need applied.65 0.5 25
2.1 the correction factor for
35°C 0.3 7.50
35 1.5 15
4 9.
Cable rating, 34.80 1.c.75 1.8 2.8
16 2.94.2, 10mm cable, having rating 46A, is
required carry this current.c.3 6.8 2.09A and will therefore choose 32A MCB for the nominal current
setting the protective device, In
