Electrical installations and wiring systems
305
Trap provides inspection
access under floorboards
to joint box
Floorboards
Cables passing through
holes drilled joists
Plaster finish wall
Metal switch box
PVC cable run down wall and
buried plaster, covered with
channel mechanical protection
is required
Plasterboard
finish ceiling
Wall
FIGURE 14. Maximum depth notch should 0. Holes the same joist should least
3 diameters apart.1 and
0.
Floor
joists
Steel
conduit
Greater than
50mm
Insulated
and
sheathed
cable
Notes:
FIGURE 14. Notches top zone between 0.22
Permitted cable routes.25 span.25
joist depth.
.23
Correct installation cables floor joists.125
joist depth.
1.
Protection required unless cable
depth greater than 50mm
No protection
required
150mm
150mm
Wall
Wall
Wall
No protection
required
Accessory
boxes
FIGURE 14.
2.4 span.25
and 0. Maximum diameter hole should 0.
5. Holes centre line zone between 0.
4.21
A concealed PVC sheathed wiring system.
3
