16
Electrical
Q&A
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
Standard
Clause
My client is relocating his factory and the
electrical equipment will be transferred
progressively over a period of time.
My contract only requires me to install
the equipment at the new location.
Can I issue one non-prescribed compliance
certificate when all the equipment is
relocated or do I need to provide a
non-prescribed certificate each time
I reconnect an item at the new location?
Each time the electrical equipment is relocated and reactivated
(put into service) or made available to the customer for use,
a Certificate of Electrical Safety must be issued. The two options are:
(a) a non-prescribed certificate when the equipment is made
available; or
(b) periodic certificate.
Electrical
Safety Act
1998
Section 45A
Could you help me with the correct
earthing arrangement for a five-unit
subdivision. The plan shows that each
building is separated from each other
and the supply originates from a pit
and has a supply distribution switchboard
with metering set back from the front
in a brick pillar.
The safest way is to establish a main earth and MEN connection
at the supply distribution switchboard and install protective earthing
conductors with the supply cables to each tenancy.
AS/NZS
3000:2007
Clause 1.4.69,
5.3.5 & 5.5.3.1
I have been asked to install an induction
cooktop. Due to the high current
requirements, 40 amps or more, is there
still a requirement to provide an isolation
switch in a readily accessible location?
Yes, a circuit for a fixed or stationary cooking appliance having an
open cooking surface incorporating electric heating, e.g. cooktop,
deep fat fryer, barbecue griddle or similar, shall be provided with
a switch, operating in all active conductors, mounted near the
appliance in a visible and readily accessible position.
AS/NZS
3000:2007
Clause 4.7.1
A periodic certificate can be used to record non-prescribed
electrical installation work at the one installation for three months.
The second option is to establish a main earth and MEN at the
supply distribution switchboard and create a separate MEN at each
tenancy. This requires each tenancy to meet the requirements of
an outbuilding and take particular care there are no conductive
pipes or such items as telecommunication cable sheaths, metallic
building materials, carports, covered walkways, etc. that may
be continuous between separate buildings and thus establish
a parallel earth/neutral path.
Switches shall be marked to identify the appliance controlled.
An alternate option is to control the circuit through a contactor.
This would enable the contactors coil to be controlled through
a conventional switch mechanism mounted on the splashback.
When installing a gas cooktop with electrical
controls and ignition, is there still a
requirement to provide an isolation switch?
Yes, where the open cooking surface is a gas appliance, the
switching device shall operate in all live (active and neutral)
conductors. The means of isolation shall be:
(a) a plug to a switched socket-outlet; or
(b) a plug to a socket-outlet that may be located in an inaccessible
position but has a separate switch operating in all live (active
and neutral) conductors located in an accessible position; or
(c) a switch operating in all live (active and neutral) conductors.
AS/NZS
3000:2007
Clause 4.18.1
In a multiple customer development which
part of the installation is prescribed electrical
installation work?
The prescribed electrical installation starts at the point of
attachment and ends and includes the electrical switchboard
within each tenancy.
AS/NZS
3000:2007
Regulation
238
If a Registered Electrical Contractor
undertakes a contract and sub-contracts
that electrical installation work to another
REC, who has the responsibility for issuing
the Certificate of Electrical Safety?
The REC who undertakes the contract remains the responsible
person and is the person who provides the Certificate of Electrical
Safety in respect of that work to the person whom the work was
carried out.
Electricity
Safety Act
1998
Section 45A
I recently bought a quantity of 1mm2
three core double insulated cable and
found it has a solid 1mm2 earth conductor.
Previously all earth conductors have
been stranded. Does this cable comply
with the Australian standards?
Yes, AS/NZS 5000.2:2006—Electric cables—Polymeric insulated—
For working voltages up to and including 450/750 V allows 1mm2
cables with a solid 1mm2 earth conductor, but requires stranded
earth conductors for other sized cables.
AS/NZS
5000.2:2006
Clause 5