
102 Electrical industries
18 x 27 x 9
.·.
Volt drop = = 2.67 V
1000
This is acceptable, as maximum permissible volt drop is 2.5% of 240 =
6 V. Hence the cooker cable would be 4.0 mm
2
. In new, unoccupied
premises it would be sensible to install 6.0 mm
2
cable, in case a larger
cooker were to be installed.
Cost of materials and systems
Having completed all necessary calculations, the type of system and its
materials must be considered carefully.
Materials
The type of dwelling we are considering would only require
P.
V.C.
twin
and earth cable, with drops to switches etc. run in an oval
P.
V.C.
conduit and buried in the plaster, and run unenclose ...