The 2007 edition of AS/NZS 3000 introduced additional requirements for the connection of electrical equipment. Darrell Hills looks at the changes and what they mean to you
In the most recent iteration, new clauses and diagrams in AS/NZS 3000:2007 were included to address problems associated with the connection of workstations (office furniture) with installation couplers (referred to as starter sockets).
The installation couplers are intended for permanent connection between sections of wiring, particularly in soft wiring systems, and the installation couplers are treated as junction boxes.
Soft wiring is regarded as installation wiring (see clause 1.4.102) and should be installed and tested by a licensed tradesperson. The following clauses and diagrams provide details of the location of installation wiring.
4.3 CONNECTION OF ELECTRICAL EQUIPMENT
4.3.1 General
Electrical equipment may be connected to the installation wiring by one of the methods detailed in Subclauses 4.3.2 to 4.3.5.
In all cases the point of connection to the installation wiring shall be as close as practicable to the electrical equipment and the connection shall be effectively protected against mechanical damage or interference.
Wiring within, and forming part of, an item of electrical equipment is considered to be equipment wiring. Such wiring shall be in accordance with the relevant product Standard or, where no relevant product standard exists, AS/NZS 3100.
4.3.2 Direct connection
4.3.2.1 General
The installation wiring of the electrical installation shall be directly connected to terminals provided on the electrical equipment for the purpose (see Figure 4.1).
FIGURE 4.1 DIRECT CONNECTION
4.3.2.2 Installation coupler
An installation coupler, enclosed or unenclosed, that meets the requirements of AS/NZS 61535 is a suitable method for the electrical connection of cables, including flexible cords, flexible cables and rigid (solid or stranded) cables.
Notes:
1 Installation couplers are intended for permanent connection between sections of wiring, particularly in ‘soft’ wiring systems, in which case they are treated in the same manner as a junction box.
2 Installation couplers require a deliberate act to disengage the latching mechanism and are not to be engaged or disconnected under load or to be used as socket-outlets.
Wiring from an installation coupler to electrical equipment is regarded as installation (fixed) wiring (see Figure 4.2).
FIGURE 4.2 DIRECT CONNECTION BY INSTALLATION COUPLER
Exception: Where the manufacturer of an item of electrical equipment provides supply terminals for the equipment at a plug designed for connection to an installation coupler, the wiring between the plug and the equipment is regarded as equipment wiring (see Figure 4.3).
FIGURE 4.3 DIRECT CONNECTION BY INSTALLATION COUPLER EXCEPTION
4.3.3 Socket-outlet
The installation wiring of the electrical installation shall terminate at a suitable socket-outlet, the wiring to the electrical equipment being continued by means of a plug and flexible cord or cable (see Figure 4.4).
FIGURE 4.4 CONNECTION BY SOCKET-OUTLET
4.3.4 Other connecting devices
Where wiring terminates at a suitable junction box, ceiling rose or terminating device for the connection of a specific item or items of equipment, the wiring from the connecting device to the electrical equipment is considered to be equipment wiring (see Figure 4.5).
FIGURE 4.5 CONNECTION BY OTHER CONNECTING DEVICES
FIGURE 4.6 EQUIPMENT WIRING –EXCEPTION FOR PENDANT SOCKET-OUTLET
4.3.5 Equipment wiring
Equipment wiring shall:
(a) Be as short as practicable; and
Note: A maximum flexible cord or cable length of 2.5 m is recommended.
(b) Have a current-carrying capacity not less than the maximum load of the connected appliance or luminaire; and
Note The minimum cross-sectional area of 0.75 mm2 for flexible cords is recommended, other than those specified for portable or hand-held appliances and luminaires
(c) Be protected against short-circuit, in accordance with Clause 2.5.4; and
(d) Where earthing is required, be provided with a protective earthing conductor of suitable cross-sectional area that will ensure operation of the circuit protective device, in the event of a fault to earth, without damage to the protective earthing conductor.
Exception:
1 Where an assessment is made of the effect of a fault in the electrical equipment and smaller conductors will meet the protection requirements, conductors with a cross-sectional area of not less than 20% of the rating of the circuit protective device may be used.
2 Wiring between a terminating device and a pendant socket-outlet is considered to be installation wiring (see Clause 3.9.7.4 and Figure 4.6).
4.4 SOCKET-OUTLETS
4.4.2 Location
4.4.2.1 Accessibility
Each socket-outlet shall be installed so that any plug intended to be used with the socket-outlet can be conveniently inserted and withdrawn and not cause damage to any flexible cord or cable connected to the plug.
Socket-outlets shall not be installed where the withdrawal of a plug from the socket-outlet is restricted by a permanent fixture or fitting within the installation.
Note: The gas code in Australia (AS 5601 require that the means of electrical isolation for a gas appliance shall be accessible with the appliance installed.
4.4.2.2 Protection of socket-outlets
Socket-outlets shall be installed so that they will not be subjected to undue mechanical stress or damage in normal service. In addition:
(a) Where installed in a floor or other horizontal surface, socket-outlets shall be designed or arranged to prevent the accumulation of dust or water therein.
Note: AS/NZS 3112 contains requirements for socket-outlets intended to be mounted in a floor.
(b) Where installed within 75 mm of a floor, socket-outlets shall be installed so that any plug used with the socket-outlet is withdrawn in the horizontal plane.
Exception: This requirement does not apply to a socket-outlet that complies with Items (a) and (d).
(c) Socket-outlets shall be so installed that a plug is not likely to become loose or to malfunction because of gravity, vibration or the weight of the flexible cord or cable.
(d) Where installed for the connection of a fixed or stationary appliance or a luminaire that is not readily accessible, the socket-outlet shall be securely fixed to a structure or support to ensure that no mechanical strain is placed on the installation wiring connections when inserting or removing a plug to the socket-outlet.
(e) The use and location of socket-outlets is restricted in a number of particular situations, including damp situations, in accordance with Section 6 and hazardous areas and other situations, in accordance with Section 7.
Where socket-outlets are installed in building surfaces that are required to provide fire-resistance or acoustic properties, measures shall be taken to ensure not these properties are maintained.
