AS/NZS 3012-2010 pdf free download

AS/NZS 3012-2010 pdf free download.Electrical installations-Construction and demolition sites.
NOTE: This provision allows for construction or demolition work in existing premises that involves the use of plug-in equipment. such as tools and task lighting, to be carried out using existing socket-outlets that are in the vicinity of the construction work. When the construction work is more significant in terms of duration, scale or equipment, arrangements should be made to have construction wiring and equipment installed that conforms to the requirements of this Standard.
2.4.6.3 Ekciricul equipmenl supplied by low— voliage generalors
LV generators complying with the principles of AS 2790 shall be connected in accordance with AS/NZS 3010 and as follows:
NOTE: LV is any voltage exceeding 50 V a.c. or 120 V d.c. but not exceeding 1000 V a.c. or 1500 V d.c. For example, welding generators with auxiliary circuits supplying 115 V a.c. that do not originate from an isolated winding is required to be RCD protected as per Clause 2.4.6.3(c).
(a) Where a site switchboard is supplied directly by a generator all sub-mains and final sub-circuits originating at that switchboard shall be protected in accordance with Clauses 2.4.5 and 2.4.6.1 as illustrated in Figure 2.1.
(b) Isolated winding generators. connected in accordance with Figure 2.2. shall only be used on construction and demolition sites to supply a separated circuit for electrical equipment. installed in accordance with the electrical separation requirements of AS/NZS 3000. Each winding shall supply not more than one item of Class I (earthed conductive parts) electrical equipment.
NOTES:
I One or more items of Class II (double insulated) electrical equipment may be connected to an isolated winding generator.
2 Portable RCDs will not operate as there is no neutral to earth connection upstream of the
RCD.
3 In some jurisdictions, the use of isolated winding generators is not permitted on construction and demolition sites.
4 The 2 pole switching shown in Figure 2.2 is required as both conductors are considered to be live—neither is earthed in normal operation.
5 The connection of the generating set bonding system to the general mass of earth through an earth electrode is not required or recommended as there is double insulation from the live parts to the frame.
6 Only one Class I item (one is based on probability) is allowed as the first fault from a live part to earth makes it a non-isolated system.
(c) Generators providing electrical supply via permanently connected RCDs with maximum rated residual current of 30 mA, operating in all live (active and neutral) conductors, and connected as per Figure 2.3. may be used to supply multiple items of eq u i pine nt.
NOTES:
I The RCD protected system allows the use of multiple Class I (metal frame with a bonding conductor) items as the first fault causes a residual current device to trip.
2 The connection of the generating set bonding system to the general mass of earth through an earth electrode is not required or recommended. At 240 V a current of 30 mA will not flow lithe fault path resistance exceeds 8 Without an earth electrode the current is reduced, but an RCD will operate at 30 mA irrespective of the arrangement. The protection required is given without an electrode. It is considered the possible fault current should be as low as practicable and hence an electrode should NOT be used.
3 This principle does not apply to the MEN system where the neutral is earthed at the source and at multiple points. (See Figure 2. I).
4 The following examples of fault current paths and currents (see Figure 2.3) have been considered when deciding an earth electrode is not required:AS/NZS 3012-2010 pdf free download.