electrical services minimum requirement - NSW Public Works

Part 1 - Installation
111.2 Conduits
Holes drilled for masonry anchors shall be 6 mm deeper than the plug or anchor and
correctly sized to the manufacturer's recommendations. Pilot holes for timber fixing shall
not be larger than the screw root diameter.
Plastic or fibre plugs shall not be used.
Conduits 20, 25 and 32 dia. shall be fixed as follows:
(a) To masonry, concrete, cement rendered walls: Ø 6 expanding sleeve masonry
anchor to accommodate an M4.5 thread. However for 20 and 25 conduits indoors
nylon anchors with mushroom stainless steel expansion nail may be used.
(b) To timber: where directed fixed, wood screw No. 8 x 20, round head. Where fixed
through fibrous cement, plaster, plaster board, etc., the screws shall be of
sufficient length to allow for the additional thickness.
(c) To sheet metal: No. 8 x 13 long, galvanised binding head, self tapping screws.
(d) To steel: M5 round head screws of appropriate length tapped or bolted.
Conduits 40, 50, 63, 65, 80 and 100 dia. shall be fixed as follows:
(a) To masonry, concrete, cement rendered walls: Ø8 expanding sleeve masonry
anchor to accommodate an M8 thread.
(b) To timber: where directly fixed, steel wood screw No. 12 x 35, round head. Where
fixed through asbestos cement, plaster board, etc, the screws shall be of sufficient
length to allow for the additional thickness.
(c) To sheet metal: No. 12 x 13 long, galvanised binding head, self tapping screws.
(d) To steel: M6 round head screws of appropriate length tapped or bolted.
111.3 Mounting Blocks
Mounting blocks shall be fixed with four screws as specified for conduits 20, 25 and 32
mm diameter.
111.4 Switchboards
The fixing of switchboards shall be as described in Clause 112.2.
111.5 Switch Panels, Boxes
Switch panels and boxes shall be fixed with four screws in accordance with 112.2.
Fixings shall be one of the following, to suit the surface:
(a) Steel wood screw, No. 8, round head, or
(b) No. 8 electro-galvanised, binding head, self tapping, or
(c) M5, round head.
(d) M8 masonry anchor.
111.6 Surface Mounted Switches
Fixings shall be as indicated in Clause 112.5.
Single gang switches shall be fixed with two screws and double gang and larger with four
screws.
111.7 Cable Troughing, Cable Tray, Skirting Troughing
Cable troughings, trays and skirting troughing wider than 100 shall be fixed at intervals of
not more than 1000 with two screws per fixing. Screws shall be steel wood screws, No.
12, round head, cadmium plated or cadmium plated M6 round head screws or No. 12
electro-galvanised, binding head, self tapping screws.
Page 22 MEW E101