South Australian Current Regulations South Australian Current RegulationsSchedule 1—Requirements for aerial lines
In this Schedule—
listed standards means the standards (both national and international), codes,
guides and other documents, as published from time to time, listed in the
Appendix at the end of this Schedule;
maximum design temperature means the maximum temperature that conductors may
reach under the influence of load current (excluding fault current), ambient
temperature of the air and solar radiation.
Aerial lines must be designed so that the lines—
(a) have
safe levels of electrical insulation; and
(b) will
carry the electrical load currents for which they are designed without
failure; and
(c) will
allow the passage of electrical short circuit currents which will enable the
correct operation of protective devices; and
(d) are
structurally secure for the environmental and service conditions for which
they are designed; and
(e)
maintain safe clearances,
so as to comply with the listed standards or achieve, to the satisfaction of
the Technical Regulator, the same or better safety and technical outcomes.
Aerial line structures, their components, conductors, cables and accessories
must, so as to ensure safe operational performance, conform to the listed
standards or achieve, to the satisfaction of the Technical Regulator, the same
or better safety and technical outcomes.
(1) The thermal
capacity of a conductor must be sufficient to pass the electrical load for
which it is designed without losing any mechanical properties that would
affect the safety of the line.
(2) Thermal ratings of
conductors must be determined in accordance with the guidelines set out in the
listed standards.
5—Short circuit ratings
(1) The conductors of
aerial lines must be of sufficient size to pass short circuit currents so as
to enable the correct operation of protective devices without losing any
mechanical properties that would affect the safety of the line.
(2) Short circuit
capacity of conductors must be determined in accordance with the guidelines
set out in the listed standards.
6—Mechanical loading conditions
(1) The mechanical
loads used for the design of aerial lines must be based on the local
environment and electrical service conditions.
(2) In determining
electrical service conditions and the physical environment under which the
line will operate, due care must be given to the consideration of extremes
that may occur, the likelihood of their occurrence and the associated risks.
(3) Mechanical loading
conditions must be determined in accordance with the guidelines set out in the
listed standards.
(1) The conductors for
use with aerial lines must be designed to withstand the mechanical loads
determined for their operation over the designed operational life of the line.
(2) Conductors for
lines must be designed so as to comply with the listed standards or achieve,
to the satisfaction of the Technical Regulator, the same or better safety and
technical outcomes.
(1) The structures and
footings for use with aerial lines must be designed to withstand the
mechanical loads determined for their operation over the designed operational
life of the line.
(2) Structures and
footings for lines must be designed so as to comply with the listed standards
or achieve, to the satisfaction of the Technical Regulator, the same or better
safety and technical outcomes.
(1) Cables and
accessories designed for facade mounting must be constructed with suitable
insulated conductors and be manufactured to be durable for the environment and
service conditions for which they are designed.
(2) In determining
electrical service conditions and the physical environment under which the
line will operate, due care must be given to the consideration of extremes
that may occur, the likelihood of their occurrence and the associated risks.
(3) Mechanical loading
conditions must be determined in accordance with the guidelines set out in the
listed standards.
(1) Aerial lines must
be designed to maintain safety clearances to the ground and other buildings or
structures under the environmental and electrical service conditions
determined for the line.
(2) In determining
circuit arrangement, electrical service conditions and the physical
environment under which the line will operate, due care must be given to the
consideration of extremes that may occur, the likelihood of their occurrence
and the associated risks.
(3) The environmental
and electrical conditions for the determination of clearances to lines must be
determined in accordance with the listed standards.
(4) Aerial lines must
be designed so that safety clearances are as follows:
(a) for
an aerial line (other than a facade mounted line) constructed to operate at a
voltage of 66 kV or less—so that the vertical or horizontal
distance from any building or structure (other than a support to which the
aerial line is attached or a support of another overhead line which crosses
the aerial line) to any position to which a conductor in the aerial line may
sag at maximum design temperature, or move as a result of normal prevailing
wind pressures, is not less than the relevant distance as set out in
Table 1;
Note—
The figures following Table 1 are to be used to assist in understanding
the information contained in the Table.
(b) for
an aerial line (other than a facade mounted line) constructed to operate at a
voltage of more than 66 kV—so that the horizontal distance from any
building or structure (other than a support to which the aerial line is
attached or a support of another overhead line which crosses the aerial line)
to the centre-line of the aerial line is not less than the relevant distance
as set out in Table 1;
Note—
The figures following Table 1 are to be used to assist in understanding
the information contained in the Table.
(c) for
an aerial line (other than a service line, other cable system or aerial line
within a substation)—so that the distance to the ground in any direction
from a position to which any part of the aerial line may sag at maximum design
temperature, or move as a result of normal prevailing wind pressures, is not
less than the relevant distance as set out in Table 2;
(d) for
a service line or other cable system—so that the distance to the ground
in any direction from a position to which any part of the service line or
cable system may sag at maximum design temperature, or move as a result of
normal prevailing wind pressures, is not less than the relevant distance as
set out in Table 3;
(e) for
a facade mounted line—
(i)
so that the distance from any part of the facade of the
building which supports a line to any position to which the line may sag at
maximum design temperature is not less than the relevant distance set out in
Table 4;
(ii)
where it is designed so the line is more than 0.3 m
from the facade of the building supporting it—so that the requirements
of paragraphs (a) and (d) are complied with.
(5) The arrangement of
and clearances between circuits, either attached to a common structure,
unattached, in shared spans or crossing, must be designed to be safe for the
environmental and electrical service conditions for which they are designed
and so as to comply with the listed standards or achieve, to the satisfaction
of the Technical Regulator, the same or better safety and technical outcomes.
(6) Aerial lines
operating at a voltage greater than 66 kV must not be installed above any
building or structure.
11—Installation of aerial lines
Aerial lines must be installed in accordance with the guidelines set out in
the listed standards.
12—Maintenance of aerial lines
(1) Aerial lines,
their structures and components must be maintained to be in a safe operating
condition.
(2) A system of
maintenance must be instituted for aerial lines, their structures and their
components, including—
(a)
predetermined processes to confirm the safe state of components;
(b)
managed replacement programs for components approaching the end of their
serviceable life.
(3) Maintenance
programs must be carried out in accordance with the listed standards.
TABLE 1: Clearance distances between aerial lines (other than facade
mounted lines) and buildings or structures
|
Direction |
Distance measured from nearest conductor (in metres) |
Distance measured from centre-line of aerial line (in metres) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |
U ≤ 1 000 V |
U > 1 000 V |
U > 1 000 V |
U > 33 kV |
U > 66 kV |
U > 132 kV |
U > 275 kV |
U > 330 kV | ||||
| |
Bare |
Bare or covered |
Bare |
Bare |
Bare |
Bare |
Bare | |||||
| | |
neutral |
with earthed screen |
without earthed screen | | |
single pole |
other | | | | |
|
Vertically above those parts of a building or structure normally accessible to
persons (A) |
2.7 |
2.7 |
3.7 |
2.7 |
3.7 |
5.5 |
6.7 |
N/A |
N/A |
N/A |
N/A |
N/A |
|
Vertically above those parts of a building or structure not normally
accessible to persons but on which a person can stand (B) |
0.1 |
2.7 |
2.7 |
2.7 |
2.7 |
4.7 |
5.5 |
N/A |
N/A |
N/A |
N/A |
N/A |
|
Horizontally from those parts of a building or structure normally accessible
to persons or that is not normally accessible to persons but on which a person
can stand (C) |
0.1 |
0.9 |
1.5 |
1.5 |
1.5 |
3.1 |
5.5 |
15.0 |
20.0 |
25.0 |
30.0 |
38.0 |
|
In any direction from those parts of a building or structure not normally
accessible to persons (D) |
0.1* |
0.3* |
0.6* |
0.1 |
0.6 |
2.5 |
4.5 |
15.0 |
20.0 |
25.0 |
30.0 |
38.0 |
|
In any direction from ground |
Refer to Table 2 or 3 |
Refer to Table 2 | ||||||||||
|
* This clearance can be further reduced to allow for termination at the point
of attachment. | ||||||||||||
Table 1 figures—
(1) Figures (a) and
(b) will assist in understanding the required minimum safety clearance for
aerial lines constructed to operate at a voltage of more than 66 kV.
(2) Figure (c) will
assist in understanding the required minimum safety clearance for aerial lines
constructed to operate at a voltage of 66 kV or less (that is, minimum
safety clearance from nearest conductor (maximum swing and sag)).
|
Vertical dimension (A) applies for example to: |
Vertical dimension (B) applies in relation to things such as: |
|
Horizontal dimension (C) applies to the same as (A) and (B) |
Horizontal dimension (D) applies in relation to things such as: |
TABLE 2: Clearance distance for aerial lines (excluding service lines,
other cable systems and aerial lines within substations)
|
Clearance distance (in metres) | |||
|---|---|---|---|
| |
Over carriageway of road |
Over land other than carriageway of road |
Over land not traversable by vehicles |
|
Bare or insulated conductor |
5.5 |
5.5 |
4.5 |
|
Insulated conductor with earthed screen |
5.5 |
5.5 |
4.5 |
|
Insulated conductor without earthed screen |
6.0 |
5.5 |
4.5 |
|
Bare or covered conductor |
6.7 |
6.0 |
4.5 |
TABLE 3: Clearance distances for aerial service lines and other cable systems
|
Location of line |
Clearance distance (in metres) |
|---|---|
|
Over a road or part of a road specified by the Technical Regulator as being a
preferred route for vehicles with loads exceeding the height restrictions
established under the Road Traffic Act 1961 or the Heavy Vehicle
National Law (South Australia) Act 2013 |
6.5 |
|
Over any part of a main road within the meaning of the Highways Act 1926
|
5.5 |
|
Over the centre of each carriageway of a public road |
5.5 |
|
Over any other part of a road |
4.6 |
|
Over any part of a driveway |
3.0 |
|
Elsewhere |
2.7 |
TABLE 4: Facade mounted lines
|
Facade situation |
Clearance distances (in metres) | |
|---|---|---|
|
A |
Clearance vertically from ground at footway level |
2.5* |
|
B |
Above windows and doors |
0.3* |
|
C |
Each side and below windows |
0.5* |
|
D |
Each side of doors and balconies |
1.0* |
|
E |
From metallic parts of buildings eg downpipes |
0.05* |
|
* This clearance may be reduced based on a proper
risk assessment in any case where additional mechanical protection is provided
to the cable. | ||
Table 4 figures—
The following figures will assist in understanding the information in Table 4.
Appendix—Standards, codes, guides and other documents relating to
aerial lines
|
In this Appendix— (a) ENA
means Energy Networks Association Limited. | |
| | |
|
Conductor - Bare overhead - Hard - drawn copper |
AS 1746 |
|
Conductor - Bare overhead - Aluminium and aluminium alloy
|
AS 1531 |
|
Conductor - Bare overhead, aluminium and aluminium alloy - Steel reinforced
|
AS 3607 |
|
Steel conductors and stays - Bare overhead - Galvanised (SC/GZ)
|
AS 1222 |
|
Steel conductors and stays - Bare overhead - Aluminium clad (SC/AC)
|
AS 1222 |
|
Galvanised steel wire strand |
AS 2841 |
|
Insulated cables | |
|
Electric cables - Polymeric insulated - For working voltages up to and
including 0.6/1(1.2) kV |
AS/NZS 5000 |
|
Electric cables - Polymeric insulated - For distribution and service
applications |
AS/NZS 4961 |
|
Electric cables - Cross-linked polyethylene insulated - Aerial bundled - For
working voltages up to and including 0.6/1(1.2) kV
|
AS/NZS 3560 |
|
Mechanical fittings for low voltage aerial bundled cable
|
AS 3766 |
|
Electric cables - Aerial bundled - Polymeric insulated - Voltages
6.35/11(12) kV and 12.7/22(24) kV - Metallic screened
|
AS/NZS 3599 |
|
Electric cables - Aerial bundled - Polymeric insulated - Voltages
6.35/11(12) kV and 12.7/22(24) kV - Non-metallic screened
|
AS/NZS 3599 |
|
Conductors - Covered overhead - For working voltages 6.35/11(12) kV up to
and including 19/33(36) kV |
AS/NZS 3675 |
|
Insulators | |
|
Insulators - Ceramic or glass - Station post for indoor and outdoor use -
Voltages greater than 1 000 V ac |
AS 4398 |
|
Insulators - Porcelain and glass for overhead powerlines - Voltages greater
than 1 000 V ac - Test methods - Insulator units
|
AS/NZS 2947 |
|
Insulators - Porcelain and glass for overhead powerlines - Voltages greater
than 1 000 V ac |
AS/NZS 2947 |
|
Insulators - Porcelain and glass for overhead powerlines - Voltages greater
than 1 000 V ac - Couplings |
AS 2947 |
|
Insulators - Porcelain and glass for overhead powerlines - Voltages greater
than 1 000 V ac - Test methods - Insulator strings and
insulator sets |
AS/NZS 2947 |
|
Insulators - Porcelain and glass, pin and shackle type - Voltages not
exceeding 1 000 V ac |
AS 3608 |
|
Insulators - Porcelain stay type - Voltages greater than
1 000 V ac |
AS 3609 |
|
Guidelines for the design and maintenance of overhead distribution and
transmission lines— | |
|
(a)
Selection |
ENA C(b)1 |
|
Insulator and conductor fittings | |
|
Insulator and conductor fittings for overhead powerlines - Performance,
material, general requirements and dimensions |
AS 1154 |
|
Insulator and conductor fittings for overhead powerlines - Performance and
general requirements for helical fittings |
AS 1154 |
|
Thermal limits | |
|
Guidelines for the design and maintenance of overhead distribution and
transmission lines— | |
|
(a)
Thermal limits |
ENA C(b)1 |
|
Current rating of bare overhead line conductors |
ENA D(b)5 |
|
Short circuit capacity | |
|
Guidelines for the design and maintenance of overhead distribution and
transmission lines— | |
|
(a)
Fault ratings |
ENA C(b)1 |
|
Mechanical loading conditions | |
|
Guidelines for the design and maintenance of overhead distribution and
transmission lines— | |
|
(a)
Mechanical loading conditions |
ENA C(b)1 |
|
Structural design actions - General principles |
AS/NZS 1170 |
|
Structural design actions - Permanent, imposed and other actions
|
AS/NZS 1170 |
|
Structural design actions - Wind actions |
AS/NZS 1170 |
|
Minimum design loads on structures (known as the SAA Loading Code) -
Earthquake loads |
AS 1170 |
|
Conductor tensions | |
|
Guidelines for the design and maintenance of overhead distribution and
transmission lines— | |
|
(a)
General |
ENA C(b)1 |
|
(b)
Calculations |
ENA C(b)1 |
|
Structures and footings | |
|
Guidelines for the design and maintenance of overhead distribution and
transmission lines— | |
|
(a)
General |
ENA C(b)1 |
|
Methods of testing soils for engineering purposes |
AS 1289 |
|
Piling - Design and installation |
AS 2159 |
|
Design of steel lattice towers and masts |
AS 3995 |
|
Steel structures |
AS 4100 |
|
Concrete structures |
AS 3600 |
|
Clearances from ground | |
|
Guidelines for the design and maintenance of overhead distribution and
transmission lines— | |
|
(a)
Environmental and loading conditions |
ENA C(b)1 |
|
Clearances from structures | |
|
Guidelines for the design and maintenance of overhead distribution and
transmission lines— | |
|
(a)
Environmental and loading conditions |
ENA C(b)1 |
|
Spacing of conductors | |
|
Guidelines for the design and maintenance of overhead distribution and
transmission lines— | |
|
(a)
Clearances |
ENA C(b)1 |
|
(b)
Environmental and loading conditions |
ENA C(b)1 |
|
Maintenance | |
|
Guidelines for the design and maintenance of overhead distribution and
transmission lines— | |
|
(a)
Maintenance and inspection procedures |
ENA C(b)1 |