Holes centre line zone between 0.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 14.1 and
0.
3.21
A concealed PVC sheathed wiring system.25 span.125
joist depth.
4.4 span.
Protection required unless cable
depth greater than 50mm
No protection
required
150mm
150mm
Wall
Wall
Wall
No protection
required
Accessory
boxes
FIGURE 14. Maximum depth notch should 0. Maximum diameter hole should 0.25
and 0.22
Permitted cable routes.23
Correct installation cables floor joists.
2.25
joist depth.
. Holes the same joist should least
3 diameters apart.
5. Notches top zone between 0.
Floor
joists
Steel
conduit
Greater than
50mm
Insulated
and
sheathed
cable
Notes:
FIGURE 14.
1
