South Australian Numbered Regulations South Australian Numbered 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 under Part 4 of the Road Traffic Act 1961 |
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* |
|
1 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 |