EnergySafe Magazine Spring 2015, issue 41 | Page 19

19

For all the latest energy safety news visit www.esv.vic.gov.au

Spring 2015
energysafe issue 41


Your electrical
questions
answered!

Compiled by ESV’s Electricity Technical
Advisor, John Stolk
EnergySafe continues its regular series
featuring some of the questions that
ESV receives on a range of electricity
installation issues, some of them relating
to gas installations. Also provided are
the answers together with references
to the Acts, Standards, Regulations and
Clauses that apply to them.

Question

Answer

What are the mandatory tests required
to be carried out to verify that the
electrical work complies and is there
documented guidance?

The following tests shall be carried out along with a visual inspection
for a low voltage electrical installation:
(a) Continuity of the earthing system (earth resistance of the main
earthing conductor, protective earthing conductors and bonding conductors)
(b) Insulation resistance
(c) Polarity
(d) Correct circuit connections
(e) Verification of impedance required for automatic disconnection of supply
(earth fault-loop impedance)
(f) Operation of RCDs
AS/NZS 3017 “Electrical Installations—Testing and inspection guidance”
sets out some common inspection and test methods.

Where the characteristics of the inverter are
not changed (e.g. a transformerless inverter
is replaced with a transformerless inverter)
is it considered an equivalent replacement?

It would only be considered equivalent if the inverter is replaced with the same
make and model.
Or the manufacturer’s designated equivalent model.

When relocating a building such as a house,
do I need to replace the switchboard that has
semi-enclosed rewirable fuses and TPS cables in
good condition but have bare earthing conductors?

Semi-enclosed rewirable fuses must be replaced with an approved overload protection
device. Final sub-circuits supplying socket-outlets and lighting must be RCD protected.
The existing TPS cables can remain if the bare earth conductor is sleeved at each
termination with green/yellow sleeving.

Can I use heavy duty PVC conduit that is not
orange in colour for a category A underground
wiring system?

Yes, the PVC conduit need not be orange in colour, but it must be heavy duty and comply
with AS/NZS 2053. However, an orange marker tape complying with AS/NZS 2648.1 shall
be placed approximately half way between the ground and top of the wiring system.

Do I need to fix cables in the roof space?

Yes, wiring systems shall be supported by suitable means, in accordance with: Clause
3.3.2.8 wiring systems shall be fixed in position, in accordance with AS/NZS 3000:2007,
by suitable clips, saddles or clamps or by means that will not damage the wiring system
and that will not be affected by the wiring system material or any external influences.
For wiring systems installed in building elements, the positioning and size of openings
and checks shall not reduce the structural strength of those building elements below the
levels required by National Building Codes. Where a wiring system consisting of sheathed
cables is installed through metallic structural members, any aperture through which the
cable passes shall be bushed or shaped to minimise abrasian of the cable. Where likely
to be disturbed, the cable shall be fixed in position at a point adjacent to the aperture.
Exceptions: Wiring system in a roof space can be installed resting on an immovable
continuous surface without further support where there is no access to the roof space
or where the space between the ceiling and roof is less than 0.6m and is further than
two metres from where a person may gain entry.

Can I install a socket-outlet for the purpose
of pool equipment within the classified
zone 1 of a swimming pool?

Yes, socket-outlets necessary for connection of pool equipment shall be permitted where:
(i) provided with the required degree of protection; and
(ii) located
(a) a
 t a height not less than 0.45m above ground level and at a horizontal distance
not less than 1.25m from the internal rim of the water container; or
(b) beneath and not less than 0.5m from the edge of a fixed continuous horizontal
barrier that is not less than 1.25m wide measured from the internal rim of the
water container; and
(iii) 
either
(c) supplied individually as a separated circuit, in accordance with Clause 7.4; or
(d) supplied as an SELV or PELV system, in accordance with Clause 7.5; or
(e) protected by a residual current not exceeding 30mA; and
(iv) 
controlled by a switch that requires manual operation and does not operate
automatically by the insertion or withdrawal of a plug.