c.
One
two-core
cable,
single-
phase a.5 18.5 13. Assume TN-S supply, that is, supply having a
separate neutral and protective conductor throughout.
or d. Calculate the minimum cable size the circuit be
protected type MCB 60878. The tables the
Regulations will give the same values, but this will simplify the problem because can.)
Reference Method B
(enclosed conduit on
a wall ceiling, in
trunking)
Reference Method C
(clipped direct)
Reference Method (on
a perforated cable tray)
or (free air)
Two cables
single-
phase a.1, 14. Conductor operating temperature: 70°C
Current-carrying capacity (Amperes): 6004, 7629
Conductor
cross-
sectional
area
Reference Method A
(enclosed conduit an
insulated wall, etc.Basic Electrical Installation Work
300
Example
A house extension has total load 6kW installed some 18m away from the mains
consumer unit for lighting.5 17.
or d.
One
two-core
cable,
single-
phase a.5 14.c.
Table 14.5 16.
or d.c.
One three-
core cable
or one
four-core
cable,
three-
phase a.5 14.5 25
4 34
6 43
10 60
16 80
25 114 119 101
35 111 141 119 148 126
50 119 133 118 182 144 180 153
70 151 125 168 149 234 184 232 196
95 182 150 201 179 284 223 282 238
.
1 9
mm2
A A
1 11.
or d.5 15.c.2 and 14.
One three-
core cable
or one four-
core cable,
three-phase
a.c.c.2 Current Carrying Capacity Cables.5 17.
Three or
four cables
three-
phase a.3 which give the relevant Site Guide Tables.c.c.
One two-
core cable,
single-
phase a.c.5
1.
One three-
core cable
or one
four-core
cable,
three-
phase a.
Design current,
Power
Volts
W
V
A
b
I
6000
230
26 09
.c. Refer
to Tables 14.c. Adapted from the IEE Site Guide Kind Permission the
Institution Electrical Engineers
Multicore cables having thermoplastic (PVC) thermosetting insulation, non-armoured, (COPPER CONDUCTORS)
Table 4D1A IEE Regulations
Ambient temperature: 30°C.c.
Let solve this question using only the tables given the Site Guide. PVC insulated and sheathed twin and earth cable will provide a
sub-main this load and clipped the side the ceiling joists over much its length
in roof space which anticipated reach 35°C the summer and where insulation is
installed the top the joists.5
2
