cem7097'3

CE-IN-CONFIDENCE

19 OCTOBER 2007

ISSUE 3 CE-IN-CONFIDENCE UNCONTROLLED COPY IF PRINTED

Procedural Guideline: Guideline Overhead Design

CEM7097 Before you begin … 1 CHECK that this printed document is the most recent version before you use it.

The online version of this document is the current version. 2 DO NOT unlawfully disclose any restricted information in this document.

To see how the law applies to you: Employee: Read your contract of employment with Country Energy. Contractor: Read your contract of engagement with Country Energy. Sub-contractor: Read your contract with the contractor engaged by us. Accredited Service Providers: comply with Country Energy policies, state acts and

regulations.

MANUAL – OVERHEAD DESIGN

CE-IN-CONFIDENCE CEM7097

19 October 2007 – Issue 3 Approved By: Group Manager Standards and Demand Management of 37

CONTENTS PAGE

1 PURPOSE .................................................................................................................................3

2 KEY TERMS AND DEFINITIONS...............................................................................................3

3 ACTIONS AND RESPONSIBILITIES ..........................................................................................4 3.1 GENERAL...............................................................................................................................................4 3.2 RESPONSIBILITIES................................................................................................................................4 3.3 METHODS OF SUPPLY ..........................................................................................................................5 3.4 METHODS OF CONSTRUCTION AND MATERIALS ................................................................................6 3.5 OVERHEAD DESIGN AND CONSTRUCTION REQUIREMENTS..............................................................7

ATTACHMENT A – LOAD TYPE AND VALUES........................................................................................30

ATTACHMENT B - LOAD DENSITY VALUES FOR ASSESSMENT OF MAXIMUM DEMAND ..................32

ATTACHMENT C - CONDUCTOR INFORMATION ...................................................................................33

4 REFERENCES.........................................................................................................................35

5 REVISIONS .............................................................................................................................37

CE-IN-CONFIDENCE UNCONTROLLED COPY IF PRINTED




1 PURPOSE

This document outlines the basic requirements for the design of all overhead distribution power lines within the franchise area covered by Country Energy so as to ensure a standardised network. Country Energy’s objective is to provide a safe, reliable, efficient and economical electricity distribution system. To achieve this objective, the overhead network shall be designed in accordance with the requirements of all Country Energy policy documents, including this document, and all the design and construction standards, specifications, Acts and Regulations referenced herein or issued by Country Energy. The design process may introduce risk to Country Energy unless the process is controlled and due consideration given to OHS issues during the design phase. Design control seeks to eliminate risks emanating from the design process through the implementation of procedures that identify and account for risk in design activities such as the construction and use of plant, equipment, facilities and processes. These design requirements apply to new works associated with customer connections (i.e. Contestable Works) and augmentation or refurbishment required by the Network owner. For information relating to subtransmission lines requirements, refer to Country Energy’s Subtransmission Line Projects Group. A specific Design Information Package (DIP) will be provided for each subtransmission project. 2 KEY TERMS AND DEFINITIONS

Unless otherwise listed, the keywords and definitions used in this document are those defined in the Energy Networks Association Publications ENA C(b)1-2006, ’Guidelines for Design and Maintenance of Overhead Distribution and Transmission Lines’.

ASP – Accredited Service Provider: an Accredited Service Provider is an individual or an entity accredited in accordance with the Electricity Supply (General) Regulation 2001 and can be an individual, partnership or company. The Accredited Service Provider has responsibility for the design or construction of the electricity reticulation installation. The Department of Fair Trading is the accrediting body for Accredited Service Providers.

CE-IN-CONFIDENCE: This is a general sensitivity label to be applied to information assets that are not to be released outside of the organisation, but are freely available to all employees and other personnel working directly for Country Energy. An example of the use of this sensitivity label would be its application to the corporate policies, forms, procedures, standards, manuals and guidelines to be applied across the organisation. For more information refer to Information Security Sensitivity Labelling and Handling CEPG1096 and CEM7063.

Customer: a customer is an entity or individual who is an end-user of electricity.

Developer: Developer, Customer, Contractor or Accredited Service Provider working on behalf of the developer, other than Country Energy Networks.

Low Voltage: for the purpose of this document is nominally 400/230 volts.

High Voltage: for the purpose of this document is nominally 11000, 12700, 19100, 22000 and 33000 volts.

Street lighting Customer: the Body controlling the standard of lighting and responsible for the applicable Street Lighting charges. For dedicated roadways, the Street Lighting customer is the RTA or the Local Council and for Community Land Title developments under the Community Land Development Act, 1989 it is the Community Association responsible for that particular development.

Subtransmission: for the purpose of this document is nominally 33,000, 66,000, 110,000 and 132,000 volts.





3 ACTIONS AND RESPONSIBILITIES

3.1 General

Distribution Substations and the electricity reticulation systems in overhead supplied developments must be installed in accordance with the requirements of this Network Standard and all design and construction standards and specifications referenced in this document or issued by Country Energy. Detailed design of electricity reticulation systems depends on assessed maximum demands, building and street layouts, street lighting requirements and other local factors. The design information and parameters specified in this Network Standard provide for minimum acceptable standards. Any deviations from this specification must be submitted to Country Energy’s Planning and Customer Connection Manager for the region in which the project is proposed for approval before they are implemented. Where new developments take place in overhead reticulated areas, Country Energy will determine the extent of undergrounding of existing overhead mains that may be necessary. For new subdivisions, dedicated roadway sites for future substations and cable easements for future use may also be required by Country Energy. For underground supply requirements refer to Country Energy document CEM7098 – Underground Design. Street lighting design may form part of the low voltage system design in new developments and must conform to the requirements of both the street lighting customer and Country Energy. Approval of the street lighting customer for the applicable street lighting charges must be obtained first before construction work commences. Refer also to Country Energy document CEM7107 – Distribution Overhead Mains – Lighting. This document should be read in conjunction with the Electrical Standards and Network Standards listed in Section 4 – References. 3.2 Responsibilities

During the course of supply negotiations the ASP shall provide all information to allow Country Energy to determine the most appropriate method of supply (as described in Clause 3.3). Accredited Designers should be aware of and advise on the possibility of any demand management opportunities and options that may be available when considering new or additional load application. Country Energy’s relevant Regional Planning and Customer Connection Manager will prepare and provide design information sufficient to enable design and construction drawings to be completed. Overhead designs must be prepared by an Accredited Designer. The ASP is responsible for the design, supply of some materials and construction of the electricity reticulation system (including substations) to supply the new development as detailed in Country Energy’s design information. The ASP is also responsible for providing local authorities and the RTA (as appropriate) with copies of the proposed construction plans at least 40 days before work is to commence and must comply with any special requirements of these authorities. These special requirements, along with any services that are in close proximity of the new development, must be indicated on the construction plan. In addition, where other authorities such as the State Rail Authority or Waterways Authority have jurisdiction over land or water impacted by development, special additional conditions may apply. As these may vary from time to time, current applicable conditions must be checked at the time of the development/construction. Accredited Designers should always be mindful of the need for safe work practices and the minimisation of operational interference between power systems and cabled telecommunication systems.





The ASP is also required to carry out an environmental review at the design stage of the project in accordance with the Environmental Planning and Assessment Act 1979 (EP & A Act). It is a requirement that the ASP considers all Environmental Planning Instruments (EPIs). Applicable EPIs in most cases will include Local Environment Plans (LEPs), Regional Environmental Plans (REPs) and State Environmental Planning Policies (SEPPs). An Environmental Impact Assessment (EIA), including bushfire protection measures as outlined in the Planning for Bushfire Protection 2001 guidelines, must consider not only the construction itself but also the ongoing operation and maintenance of the assets. Where easements are required, it will be the responsibility of the ASP to arrange for such easements in favour of Country Energy and in accordance with the relevant information contained in this or other documents issued by Country Energy. Accredited Designers (Level 3 ASP’s) are responsible for arranging where necessary the identification and/or survey and the pegging of boundaries so as to allow plant and equipment to be correctly installed and to simplify auditing on completion of the installation. Level 1 and/or Level 2 ASP’s are responsible for “Non Electrical Work” such as tree clearing, excavation, restoration, landscaping and any construction that supports the electrical work. It is important to note that it is the responsibility of an ASP to report any Network component associated with or being considered in a project that may be in an unsafe or dangerous condition to Country Energy’s local Area Co-ordinator for assessment and remedial action. Certain non-electrical work, including work within close working distance of the existing electrical network, must be undertaken in accordance with Country Energy’s Electrical Safety Rules subject to specific accreditation requirements. The customer (end user) is responsible for supplying and installing the portion of service mains from the street alignment to the customer’s terminals in accordance with the NSW Service and Installation Rules. 3.3 Methods of Supply

Basically, there are four approved methods of supply. The appropriate choice to be utilised is dependent on the assessed and foreseeable maximum demand of the development. The decision as to the most appropriate method of supply will be made by Country Energy’s relevant Regional Planning and Customer Connection Manager as part of the supply negotiation phase. This initial step in the process of establishing an electricity supply involves exchange of details pertaining to the development between the developer, customer and Country Energy. The options for electricity supply are: 3.3.1 Service from the existing low voltage reticulation system – nominally 400/230V

This may provide for the connection of services (overhead or underground) rated up to 400 amps. Overhead services should be restricted to a rating of 275A or 4-core 150mm2 LVABC. This method of supply is limited by the available capacity of the existing reticulation system and the associated distribution substations. Reference should be made to the NSW Service and Installation Rules. 3.3.2 Direct Distributor – nominally 400/230V

Overhead mains taken from a distribution substation remote from the customer’s premises which can, subject to certain constraints, supply up to 400 amps. This method of supply is restricted by voltage drop and the capacity of the distribution substation, as well as fluctuation, distortion and interference considerations, as defined in NSW Service and Installation Rules.





Reference is made to CEM7104.27 – Connection to Distribution Substation. 3.3.3 Customer Substation – nominally 11000, 22000 or 33000V/400/230V

Country Energy may determine that the existing LV network is unable to meet the ASP’s supply requirements. In such cases, the ASP may be required to provide a suitable space and approved easement or lease to accommodate Country Energy’s transformer(s), pole, switchgear and other associated equipment. Generally, supply by this method will be restricted to the capacity of a 500kVA pole-mounted substation or a 1500kVA padmounted substation rated appropriately for the load cycle imposed by the customer, however, larger installation may be possible. A list of all distribution substation types and their approximate ratings is provided in Clause 3.5.10. Where supply is taken direct from a customer’s substation, the customer’s main switchboard shall, wherever practicable, be located immediately adjacent to the substation. If the customer’s main switchboard cannot be located immediately adjacent to the substation, the proposed location must be approved by Country Energy’s local Customer Service Planning Section before the design proceeds. 3.3.4 High voltage Supply – nominally 11kV, 22kV and 33kV

Consideration will be given to application for high voltage supply in accordance with the requirements of the NSW Service and Installation Rules where, in the opinion of Country Energy, it satisfies technical or economic considerations and the customer is able to safely operate and maintain the high voltage network. This option is not available in some areas and is restricted to premises with single customers. Where this option is considered a possibility and the supply voltage is higher than 11kV, Country Energy will provide the design information to the developer as required on a project-specific basis. 3.4 Methods of Construction and Materials

Country Energy’s Network Division is the determining authority as to the form of construction to be used for individual projects, including contestable works. Country Energy’s networks have been categorised as urban and rural. Rural networks are as defined as that part of a network:

a where the average demand on the high voltage feeders within it is less than 0.3 MVA/km, or

b that is in an area zoned as rural under a local environment plan (made under the Environmental Planning and Assessment Act 1979 (NSW) or

c that is in an area that is predominantly used for agricultural purposes and may include isolated industrial/commercial developments. Urban network is defined as that part of a network that is not a rural network. In urban areas where overhead construction is specified for high voltage reticulation the small delta construction shall be used and for low voltage reticulation, low voltage aerial bundled cables shall be used as the standard construction. In rural areas Country Energy shall stipulate the type of construction to be used and material types as may be appropriate in identified bushfire-prone areas. Where overhead construction is specified for high voltage reticulation (eg rural networks) the construction shall be either of the open wire construction type or covered conductor type. Country Energy shall be the determining authority as to which type is the most appropriate and may also stipulate material types to be used in identified bushfire-prone areas. In general, it is expected that high voltage lines in rural areas shall utilise the standard delta configuration. The general guidelines for the form of construction for each project shall be determined by Country Energy’s relevant Regional Planning and Customer Connection Manager and shall be in accordance with the prevailing





policy of the time. The final interpretation and decision as to the type of construction to be used shall be as stated in Country Energy’s design information package issued for the project. It is NOT anticipated that flat construction be used for high voltage lines except in a dual circuit mid-pole situation. The use of high voltage raiser brackets to retrofit existing low voltage overhead lines is NOT a standard construction. The gas switch is the standard switch to be used on the Country Energy distribution network. Where an ASP has reason to prepare a design that varies with the requirements stipulated in the Country Energy Construction Manual, the designer must seek permission from the Manager Planning and Customer Connection for the region in which the project is proposed before proceeding with the variation. Extension of the low voltage mains is by overhead reticulation unless it is an extension off an existing underground network. Country Energy may agree to the undergrounding of the low voltage reticulation if requested by the ASP or if it is a stipulation of subdivision approval by the local council. 3.4.1 Materials

Materials to be used for all overhead construction works are to be new and equivalent or superior in terms of total lifetime performance as those issued and used by Country Energy and assessed for compliance with the appropriate Country Energy specification. Where materials are intended to be supplied that are not sourced directly from Country Energy or do not meet Country Energy’s specifications and are not included in Country Energy’s Approved Materials Inventory list; these shall be indicated for assessment during the design-checking phase, i.e. the design shall be assessed for compliance with this standard on the basis that materials and equipment to be used are of equivalence to that which would be used and supplied by Country Energy. Where materials are sourced from other than Country Energy, evidence of compliance with Country Energy’s specifications or manufacturer’s certificate of equivalence to that supplied to Country Energy shall be required. Designers intending to use alternate materials are advised to discuss this situation with Country Energy’s Standards Group for evaluation of the alternatives proposed before making such decisions. There will be a charge for these services based on the fees established by the Independent Pricing and Regulatory Tribunal. 3.4.2 Reporting Potentially Dangerous Conditions

If the Level 3 ASP (Designer), during the design stage, or the Level 1 or 2 ASP, during the pre-job hazard assessment check or during the progress of work, believes that a pole or other network component may be in an unsafe or dangerous condition, such pole or other network component must be reported immediately to Country Energy’s local Area Co-ordinator for assessment and remedial action. 3.5 Overhead Design and Construction Requirements

Overhead power lines within Country Energy’s franchise area should be designed and constructed in accordance with:

• This document.

• Energy Networks Association publication ENA C(b)1-2006 – ‘Guidelines for Design and Maintenance of Overhead Distribution and Transmission Lines’.

• Country Energy’s policy CEM7099 – Standard Overhead Construction Manual.

• CECG1000 – Safety, Health and Environmental Management.





The following sections include general issues as a guide for designers. 3.5.1 Environmental Considerations

Designers need to be the complete environmental practitioner and be aware of environmental implications of route selection, materials and equipment etc as they may impact on the environment. “It is a requirement that all proposed work must have an appropriate impact assessment carried out in accordance with the Environmental Planning and Assessment Act 1979 (EPA Act) and in accordance with Country Energy Procedural Guideline CEPG2016 – Environmental Impact Assessment. For part 5 assessments under the EPA Act refer to Country Energy documents CEPG2295 Environmental Procedures Supplementary Notes, CEFD6024 – Environmental Impact Assessment form and CEFD6470 Consultant checklist for preparation of REF for further details”. 3.5.2 Vegetation Management

Reference is made to Country Energy document CEPG8008 – Vegetation Management Plan. The clearing of vegetation to enable the construction of a new power line should be carried out in accordance with document CEPG2010 – Vegetation Clearing Guidelines for New Power Lines. Should it be necessary for vegetation to be removed near existing overhead power lines then this work should be carried out in accordance with document CEPG2021 – Removing Vegetation Near Overhead Powerlines. 3.5.3 Easements

Where an overhead power line, (either existing or new), other than a dedicated connection asset on the connecting customer’s property, are not or cannot be constructed within a public road reserve, then an easement will generally be required. Such easements shall be provided in favour of Country Energy. Easement widths required will generally be in accordance with the Industry Guidelines (ISSC20) and are reproduced in the Country Energy document CEPG8046 – Easement Requirements. Where easements are required in association with new customer connections that are funded by the customer, all costs associated with obtaining these easements shall be borne by the customer, some of those costs being:

• Survey costs

• Consultation costs (eg Crown Land)

• Land valuation expenses

• Compensation payments

• Legal expenses, etc. Where easements are required in association with Network-funded projects (eg augmentation of shared assets) the costs associated with obtaining those easements shall be borne by the Network owner. Where projects involve both shared and dedicated assets, the costs shall be apportioned between the customer and Country Energy Networks, based on:

• New versus existing assets

• Works initiated by ‘the proponent’ Reference is made to CEPG8046 – Easement Requirements for additional information.





3.5.4 Construction Plans

A primary function of the design process is to produce a construction plan for use by the customer to engage an ASP or contractor to construct those assets. Once constructed, Network assets are generally transferred to the Networks owner and need to be added to various asset databases, maps, plans, GIS etc. For these reasons, it is essential that certain minimum information is included on the construction plans with a reasonable level of standard symbology to allow:

• An ASP to construct those assets

• Network personnel to update their asset records system All design and construction plans shall use the standard symbols and be in the format nominated in draft document CEM7001 – Construction Drawing Standard Symbology. All network project design and construction plans are to be identified with a unique project number. Reference is made to previous Clause 3.2 as to the responsibilities of an ASP in the provision of the necessary information on the construction plan as well as providing information to the appropriate authorities. On completion of the construction of a new line, the following ‘as built’ information is to be recorded/updated on the construction plan:

• As constructed line/pole schedule

• Final as constructed route plan

• Final height of the lowest conductor above ground at the nominated design maximum operating temperature along the route of the line

• Conductor stringing tensions and tables

Alternatively, a separate design information sheet, or a copy of the design information as provided from an approved software package displaying the same unique project number as the project drawing, can be provided. This design information should include conductor stringing details such as the design tension, initial sags, the final sags and the minimum ground clearance at the nominated design operating temperature. Also required is the conductor final tension at 5°C with no wind in addition to the conductor tension under the wind/ice loading condition if applicable to the installation location.

• Line profile for rural extensions, where terrain profile varies by >5% at any point in a span and the ruling span exceeds 100 metres, or terrain profile is >10% in addition to the provision of property schedules. Alternatively, a designer may opt to retain a separate profile that can be produced if and as required by Country Energy for audit purposes. Recommended scale for route profiles are 1:2500 horizontal and 1:250 vertical.

• Pole foundation details if they vary from the minimum prescribed in Clause 3.5.9.1 of this document.

• Other assets attached to Country Energy’s poles. 3.5.5 Network Asset Identification

Any asset added to Country Energy’s electrical network must be labelled in accordance with Country Energy policy CEK8042 – Distribution Asset Numbering and Operational Number Labelling. 3.5.6 Overhead Distribution Line Design Parameters

Reference is made to the publication by the Energy Networks Association Publication ENA C(b)1-2006, being the basis for all Overhead Line Design, and Country Energy’s Overhead Construction Manual CEM7099. The following additional information is provided to assist in the design process:





3.5.6.1 Assessment of Maximum Demand

The demand for an individual development shall be assessed in accordance with Australian Standard Publication AS3000, based on appropriate diversity factors being applied to a submitted list of maximum demands for all items of equipment. These factors should be used in conjunction with discussions with the ASP to ensure there are no mitigating circumstances that would negate or reduce their use. Where either actual surveyed load data for upgrade work or assessed maximum demands are not provided for new designs, then recommended After Diversity Maximum Demands (ADMD’s) may be used. Recommended ADMD’s in accordance with the requirements of Country Energy’s document CEPG8003 – Subtransmission and Distribution Network Planning Criteria and Guidelines are provided in Attachment A. Where the ADMD in conjunction with the utilisation factor as provided in Attachment A is used to assess the transformer capacity required for a project, then a common sense/realistic approach should be adopted. There will be occasions, mainly in rural situations, where it may be necessary to differentiate between the various listed ADMD’s to suit a particular project. One project may, due to the type of housing, be assessed at 7.0kVA/dwelling whereas another project may be assessed at 4.0kVA/dwelling for sizing transformers. In the case of industrial, commercial and multi occupant developments, if a full list of connected loads is not initially available, Country Energy will nominate a load density value in VA per square metre for floor area used as provided in Attachment B. It is also essential that the assessed maximum demand appropriately incorporates any definitive plans that the customer has for expanding or augmenting the development in the foreseeable future. 3.5.6.2 Maximum Low Voltage Distributor Loading

The following design criteria for the initial electrical loading on low voltage distributors must be satisfied:

• The designed maximum load on any LV distributor must not exceed 75% of the distributor’s nominal rating, unless otherwise nominated by Country Energy. This provides a reasonable margin for load growth and paralleling requirements. Distributors are nominally rated in accordance with the ambient temperature, the temperature rating of the style of construction and type of conductor and associated cross-sectional area of materials used.

• The load to be connected to a distribution centre must be balanced across the LV distributors and their respective phases, unless agreed otherwise.

3.5.6.3 Maximum Voltage Drop

The ultimate voltage level to be maintained at the Point of Supply should be not less than 226 volts and not greater than 253 volts, in accordance with Country Energy’s documents CEPG8003 – Subtransmission and Distribution Network Planning Criteria and Guidelines and CEK8026 – Electricity Supply Standard. The designed maximum voltage drop, as determined by “LVDROP” in a low voltage distributor must not exceed 9V at the extremities. “LVDROP” is a design package used by Country Energy to assess the affect of new developments connecting to its LV network and is based on established engineering principles as outline in Section 4 of publication AS/NZS 3008.1.1. Note: Service mains are not regarded as part of the distributor. The voltage drop in the service mains must not exceed 1% at full load. The maximum three phase volt drop constants for distributor and service must be calculated and supplied with the design details.





Voltage drops shall be determined using ‘LVDROP” software (Version 5.48 or later) and the load information, provided in Attachment A & B and conductor impedance values as provided in Attachment C. Voltage drops submitted with the design will be checked by Country Energy using the same methodology and information. 3.5.6.4 Quality of Supply

The designer shall ensure that his design is satisfactory to supply customer equipment that has the potential to cause interference to other customers. Arc furnaces, welding machines, X-Ray units and frequently started large motors are examples of equipment that can cause excessive fluctuation of voltage. The design shall comply with the limits specified in the New South Wales Service Rules, Clauses 1.9.1 to 1.9.12 and meet the requirements of the series of Australian Standards 61000 for all aspects of electromagnetic compatibility, particularly for voltage flicker and voltage fluctuation. 3.5.6.5 Levels of Reliability

Low Voltage in Urban and developed areas Alternate supply to LV distributors must be provided from adjacent distribution centres wherever practicable. Each distributor will normally require two alternate points of supply to allow low voltage paralleling under maximum demand conditions. Every opportunity must be taken to establish loop feeds where loop roadways exist (i.e. interconnection between distributors from the same distribution centre or between different branches of the same distributor). Extension of distributors beyond that necessary to provide a paralleling path will not normally be required unless nominated otherwise by Country Energy’s relevant Regional Planning and Customer Connection Manager.

High Voltage During the course of supply negotiations Country Energy’s relevant Regional Planning and Customer Connection Manager will determine the minimum level of high voltage reliability required and provide this information as part of its design information. In doing so, Country Energy will take into account the level of reliability of the existing network, type of existing construction (i.e. overhead or underground), permissible number of ‘Tee off connections’ allowed, permissible number of substations on a radial supply (both on a temporary and permanent basis), future load growth and any other network requirements. All costs associated with levels of reliability in excess Country Energy requirements shall be met by the customer.

Low Voltage Services The installation and connection of all service mains shall only be carried out by suitably accredited and authorised Level 2 Service Providers in accordance with the NSW Service and Installation Rules. In urban areas, under no conditions are new service mains to be erected so as to cross over the boundary of any property other than that property for which the service is intended. Standard overhead services acceptable for connection to Country Energy’s LV network are those provided in Table 3.5.7.3.





3.5.6.6 Clearances and Spacings

All new overhead lines that are to be erected and connected to Country Energy’s network shall have as a minimum requirement the clearances and spacings provided in publication ENA C(b)1-2006, Country Energy’s Overhead Construction Manual documents CEM7106.25, CEM7106.26, CEM7106.27 and Table 3.5.6.6 of this document. Where the clearances stipulated in the following Table 3.5.6.6 and those stipulated in documents CEM7106.25, CEM7106.26 and CEM7106.27 exceed those provided in publication ENA C(b)1-2006 then the values stipulated by Country Energy shall take precedence. The maximum conductor operating temperature that apply to the design clearances shown in Table 3.5.6.6 are provided in Clause 3.5.6.7.

Distance to ground in any direction (m)

Nominal System Voltage Over the carriageway of

roads Over land other than the

carriageway of roads

Over land which due to its steepness or

swampiness is not traversable by vehicles

Bare low voltage (400/230 Volt) Mains 6.0 6.0 5.0

Insulated low voltage (400/230 Volt) Mains 6.0 6.0 5.0

Insulated conductor without earthed screen, bare conductor or covered conductor: 11, 22 and 33kV 66 and 132kV

7.3 8.0

6.0 7.3

5.0 6.0

Table 3.5.6.6 – Clearance from Ground for Overhead Lines other than Insulated Service Lines Notes:

1 For the purpose of this clause, the term ‘ground’ includes any unroofed elevated area accessible to plant or vehicles.

2 Ground clearance over the carriageway of road includes a distance of up to 4 metres on either side of formed surface.

3 Where the usage of land is such that vehicles of unusual height are likely to pass under an overhead line, the clearances given in this clause may need to be increased.

4 In special circumstances Country Energy’s relevant Regional Planning and Customer Connection Manager may approve that the design ground clearance be reduced to that provided in ENA C(b)1-2006.





3.5.6.7 Standard Design Temperatures The Country Energy standard design temperatures for overhead lines are as provided below:

Nominal Voltage Conductor Type Situation/Location

Design Maximum Operating

Temperature

Low Voltage All conductors All locations 65° C

11kV, 22kV & 33kV SC/GZ Where permitted 50° C

ACSR or AAAC Minor Rural distribution backbone lines 65° C

11kV, 22kV & 33kV AAAC Town mains and Major rural

distribution backbone lines 75° C

66kV & 132kV All conductors All subtransmission locations 85° C

Table 3.5.6.7

3.5.7 Standard Overhead Conductors and Cables

Standard Overhead conductors and cables approved by Country Energy for use in the overhead network are described as follows: 3.5.7.1 Bare Overhead Line Conductors

The general principles for the use of bare overhead conductors on Country Energy’s Distribution networks are:

a Low voltage – restricted usage only, i.e. LVABC should be used wherever possible. Approval required from Country Energy’s relevant Regional Planning and Customer Connection Manager before installation of bare conductor.

Low voltage spreaders are to be attached to all three or four wire bare LV approved installations where:

• The span is less than 45 metres and

• is adjacent to overhanging trees and/or

• will be in line with trees that require regular lopping.

• conductor clashing due to stringing terrain is possible.

• The span is greater than 45 metres (one spreader mid span for up to 90 metre spans)

• The span is greater than 90 metres (two spreaders, one at each third of the span)

Construction plans are to show the number and location of LV spreaders that are to be installed in the project.

b 11kV, 22kV and 33kV – standard bare conductors should be used except in the following

circumstances:

• where the area is identified as bushfire prone in accordance with Country Energy document CEK8022 – Network Bush Fire Risk Management Plan OR

• where substantial tree cover does or will exist OR

• where proximity of trees will or do present a problem OR





• where proposed ongoing tree trimming requirements will be cost and/or environmentally prohibitive OR

• where there are restrictions on the removal/trimming of trees due to heritage listing or trees being of significant value to the community OR

• where approved projects dictate that alternative arrangements are necessary

AND

• the use of alternative conductors is the most economical and environmentally acceptable solution after all other alternatives have been exhausted.

Standard bare conductors are:

Country Energy Catalogue No

Stranding/ Wire Diameter/ Conductor type

Code name Country Energy Specification No.

444060 3/2.75 SC/GZ * Refer note below CES5104.13

443220 3/4/2.50 ACSR Raisin CES5104.17

443910 7/3.00 AAAC Fluorine CES5104.23 item 1

443970 7/4.50 AAAC Hydrogen CES5104.23 item 2

440970 19/3.75 AAAC Neon CES5104.23 item 3

Table 3.5.7.1

* Note: Installation of 3/2.75 SC/GZ, galvanised steel conductor is not generally encouraged and will require the approval of the relevant Regional Planning and Customer Connection Manager prior to construction. The installation of 3/2.75 SC/GZ will NOT be permitted within 50km of the coastline, or tidal waterways, or within a 10km radius of an existing or planned zone substation in accordance with Country Energy document CEK8003 – Subtransmission and Distribution Network Planning Criteria and Guidelines. 3.5.7.2 Stay Wire

Country Energy Catalogue No Description CE Specification No.

600460 19/2.00 SC/GZ CES5104.43

600490 19/2.75 SC/GZ CES5104.45

Table 3.5.7.2

3.5.7.3 Low Voltage Aerial Bundled Cable (LVABC)

LVABC is the standard overhead cable to be used throughout the Country Energy LV networks.





Standard LVABCs are:


445680 0.6/1kV 2-Core 25mm2 XLPE Stranded Aluminium LVABC CES5102.05





Table 3.5.7.3

3.5.7.4 High Voltage Aerial Bundled Cable (HVABC)

HVABC is generally restricted to urban installations where trees are directly under the mains that are to be installed or upgraded or where a minimum tree clearing envelope is required. Before adopting HVABC, alternative options should always be investigated as more economical and environmentally acceptable alternatives or route options may be a solution. Standard HVABC’s are:


447300

11kV 3-Core 50mm2 stranded Aluminium (7/5.00 AAAC) XLPE

insulated, non-metallic screened, HDPE sheathed

CES5102.43

447310

11kV 3-Core 150mm2 stranded Aluminium (19/3.65 AAAC) XLPE insulated, non-metallic screened,

HDPE sheathed

CES5102.47

Table 3.5.7.4

3.5.7.5 High Voltage Covered Conductor (CCT)

The installation of High Voltage CCT should generally be restricted to route lengths in excess of 100 metres where:

• the area has been nominated as a bushfire risk area OR

• there is a substantial number of trees adjacent to each span of the line to be constructed or augmented AND

• it will be possible to trim the trees so as to maintain the clearances required under Country Energy’s Vegetation Management Plan AND

• where all other economical and environmentally acceptable alternatives have been exhausted.





Standard HV CCT for use on Country Energy’s distribution networks are:

Country Energy Stock No Description CE Specification No.

441120 11kV 1-Core 40mm2 stranded Aluminium

(7/2.75 AAAC/1120) XLPE (X-90) covered, HDPE sheathed

CES5103.02

441130 11kV 1-Core 80mm2 stranded Aluminium


CES5103.04

441135 11kV 1-core 120mm2 stranded aluminium

(7/4.75 AAAC/1120) XVPE (X-90) covered, HDPE sheathed

CES5103.06

441140 11kV 1-core 180mm2 stranded aluminium


CES5103.08

Table 3.5.7.5

High Voltage CCT is an insulated unscreened conductor and does not require an earthing system to maintain its integrity. However, the system requires Current Limiting Arcing Horn & Discharge Connector (CLAH/DC) to divert surge energy, resulting from lightning strikes, to earth. The CLAH/DC units are to be installed at intervals of not more than 400 metres giving a protection zone of 200 metres either side of the unit installation. Surge diverters are to be provided on substations and at underground to overhead interfaces. 3.5.7.6 Conductor Fittings

At intermediate locations/structures, conductors will be attached to insulators by various fittings or combination of fittings including ties, armour rods, suspension clamps and vibration dampers where applicable. Where damping is required, spiral vibration dampers should be used on bare overhead conductors and CCT cables up to and including 7/4.50. Stockbridge or ‘dog-bone’ dampers are to be installed on larger conductors. Preformed dead-ends are to be used at all termination/strain points. General requirements are:

• Vibration dampers should be used on all spans where the design tension exceeds 18% of the conductor CBL.

• Vibration dampers should be used on all spans of SC/GZ or ACSR conductors greater than 300 metres.

• Vibration dampers should be used on all spans of AAAC (1120) conductors and CCT cables greater than 200 metres.

• The requirement for vibration dampers may be reduced in forest areas where the smooth laminar airflow is broken by the vegetation profile.

• Refer to the Overhead Construction Manual for details on placement and fitting of vibration dampers.

• Conductor uplift conditions must be avoided at all intermediate positions.





3.5.8 Standard Stringing for Overhead Conductors

Selection of conductor tension to be used on a project is generally a compromise due to the many variable components. Geographic features (i.e. road formations, property boundaries, land profile, soil properties, accessibility, vegetation, environmental considerations etc) and not necessarily stringing tensions will ultimately govern the positioning of most poles. Using higher tensions could result in fewer and/or shorter poles but may require higher strength poles, crossarms, fittings, footings and stays and might not prove to be the best overall economic, environmental and maintenance-effective solution. For overhead line design it is usual to use a tension at a reference temperature with no transverse wind for design purposes. This reference tension is the long term average tension in the conductor/cable and is the recommended design tension listed in the following tables. The reference temperature normally used throughout Australia is 15°C. When calculating maximum sags for new conductors, allowances shall be made for conductor creep and for minor errors in construction, by allowing for an extra 5 or 10˚C in conductor tension calculations. For example, if a conductor is to be strung at 6,000 N at 15˚C, then the final design should be based on assuming conductor tension is 6,000 N at 5˚C for aluminium conductors and 10°C for steel conductors. This additional creep allowance does not have to be applied to existing conductors which are being diverted or reconstructed. In the initial design process, unless indicated otherwise in the design brief, or the actual temperatures in accordance with the definitions provided in ENA C(b)1 – 2006 are available, the following conditions may be used.

• For uplift conditions in Coastal and Western regions – 5˚C and in Tablelands and Ranges – 10˚C.

• The serviceability limit states for sustained load conditions in South, Mid and North Coastal regions 15˚C and Far South Coastal and other regions 10˚C.

Unless otherwise indicated in the design brief, the minimum operating temperature shall be taken as 5˚C. The maximum operating temperature shall be as per Clause 3.5.6.7 of this document. For inter-circuit clearances, the upper circuit shall be assumed to be at maximum operating temperature while the lower circuit is at minimum operating temperature. When this requirement imposes the need for increased pole heights or reduced span lengths, then the design shall be discussed with Country Energy’s representative. Country Energy’s representative may under some conditions permit the design to be based on the assumption that the lower circuit will be operating at the sustained load condition temperature. The need for pole changes would then be reviewed. Unless otherwise indicated in the design brief, for blowout calculations, the conductor is assumed to be at 50˚C and under wind loads specified in ENA C(b)1-2006. For overhead lines constructed along streets in urban areas, span lengths are normally restricted to less than 100 metres for HV only and less than 50 metres for dual circuit HV and LV or LV only. In these cases, high tensions provide little or no additional benefits. For urban areas, the recommended design tensions for Country Energy’s overhead distribution networks are provided in Table 3.5.8.1, for which stringing tables are included in the Overhead Construction Manual.





Recommended Design Tensions as % CBL for Various Applications

Conductor Type Urban Commercial/

Industrial

Urban Dense Residential

Urban Residential Semi-Urban

AAAC (1120) Bare 3% 3% 3% 9%

AAAC (1120) CCT 4% 4% 4% 7%

AAAC (1120) HV ABC 11% 11% 11% 18%

LV ABC Refer Note 1 4% 4% 4% 7%

Table 3.5.8.1

Note 1: General rules for installation of Low Voltage Aerial Bundled Cable (LVABC) as listed in Clause 3.5.7.3 are:

• In span tension joints are not permitted for new installations.

• Maximum everyday final tensions shall not exceed the values indicated in Australia/New Zealand Standard AS/NZS3560.1:2000 LESS 2.5% and are as follows:

25mm² 2 core = 1.1 kN max





• Tensions in excess of 7% CBL should be avoided if installing insulation piercing connectors (IPC) in tension span, due to difficulty experienced in insertion of plastic wedges to separate cores. Alternative in rural areas is to insert IPC’s into non tension section.

For lines constructed in non-urban or rural areas, the base case horizontal design tensions should not exceed those permitted in ENA C(b)1-2006. For example, where a base case horizontal tension of 15% of CBL is permitted for AAAC/1120 conductor, lines shall be designed to be erected at no more than 15% plus the appropriate incremental increase that may be allowed for static stress and dynamic stress considerations.





For rural areas, the recommended maximum design tensions for Country Energy’s overhead distribution networks are provided in Table 3.5.8.2. In regions where overhead lines may be subject to snow/ice loading, special conditions as described in ENA C(b)1-200 Clause 3.4.2 shall apply.

Recommended Maximum Design Tensions as % CBL for Various Applications

Conductor Type

Rural Residential Rural All Terrain No Dampers

Rural All Terrain Fully Damped

SC/GZ 6% 13.5% 26%

ACSR 6% 13% 23%

AAAC (1120) Bare 9% 17% 21.5%

AAAC (1120) CCT 7% 11% n/a

AAAC (1120) HV ABC 18% 18% n/a

LV ABC Refer Note 1 7% 11% n/a

Table 3.5.8.2

3.5.9 Poles

Overhead power poles and their foundations should be designed in accordance with publication ENA C(b)1-2006, taking into consideration the following requirements: 3.5.9.1 Pole Foundations

Foundation design should be based on soil test, information or an estimate of soil parameters which should be recorded on the construction plan. As a general principle only, the minimum depth for an unstayed pole in ground should be 0.8 metre plus one tenth of the pole length, but it is recommended that pole foundation designs as established using an approved design program be provided with each project. Country Energy has a preference for not concreting pole footings. Alternatives to be considered are:

• Use a heavier pole (kN strength rating) to increase the circumference and soil-bearing area

• Increase setting depth

• Utilise specified backfill such as ‘crusher dust’. Where pole foundations must be concreted, then the concrete is to stop 450mm below ground line to facilitate future pole inspections. 3.5.9.2 Pole Staying

Designers shall consider the use of heavier rated line poles and foundations as an alternative to the use of stays, in the design process. Where pole stays are required, then the following should be taken into account: Ground stays are generally preferred to overhead stays due to cost and ongoing maintenance of additional stay pole. Where access permits, ground stays are generally preferred to sidewalk stays.





Ground stays should be avoided in stock (e.g. cattle and horse) paddocks due to the fact that stock rubbing against stay wire can cause system operation problems. When alternate locations are not possible a stay guard rail shall be used as shown in Country Energy’s Overhead Construction Manual drawing, CEM7103.16. Screw anchors, where soil conditions permit, are preferred to baulks. 3.5.9.3 Pole Placement

Generally, when selecting pole locations, consideration should be given to minimising the number of poles to be installed without causing future encroachment problems and to locate poles to provide ongoing access for maintenance and operations. A minium clear space shall be provided around network assets including pole substations, in accordance with the clearances required in Section 8 of the Easement policy, CEPG8046, irrespective of whether an easement exists at the site. All pole substations shall be positioned in a location that allows access at all times, by a crane borer/erector. In urban areas, line routes should be selected so as to negate or reduce the need for road crossing (service) poles and new or replacement poles should have a clearance of 1 metre from face of kerb to face of pole, wherever practical. Poles for low voltage construction should generally be positioned every second property boundary so as to eliminate service encroachments on neighbouring properties. Footpath allocations may also vary between Local Government areas. Some poles (eg streetlight poles, road crossing poles etc) will ideally be placed near the property alignment. Elsewhere, roadside poles should have setbacks as outlined in the ‘Pole Setback Zones’, Section B6 of AS1158, Part 1.3; 1997 ‘Vehicular Traffic (Category V) Lighting – Guide to Design, Installation, Operation and Maintenance’. Poles in rural areas should not be installed too close to fences. Apart from the electrical hazard arising from step and touch potentials, pole and line inspectors require an area around poles to allow for routine inspection. A minimum separation of 1.5m between fence and pole is recommended. 3.5.9.4 Pole Type

At distribution voltages, (LV, 11kV, 22kV and in some instances 33kV) the usual pole of choice is a full length preservative-treated timber pole, in accordance with Country Energy’s specification – CEPG5124.10. However, on feeder segments designated by the responsible Planning and Customer Connection Manager as being suitable for conductive pole installation and in certain situations where it can be cost justified, designers may consider the conductive pole alternatives allowed in the Construction Manual. Examples are:

• Known termite areas

• Where the existing line is constructed with concrete poles

• Where a customer requests a particular pole type Additional information on pole types are as follows:

a Wood Poles – the strength and dimensions of wood poles for use in the Country Energy distribution network shall be in accordance with the information provided in section CEM7101.03 of the Overhead Construction Manual.





b Concrete Poles – Concrete poles may be used in “special” or “frequented” locations where common multiple earth neutral (CMEN) earthing requirements can be achieved. All concrete poles in these locations must be bonded to the LV neutral conductor or to a special CMEN conductor to ensure that they are touch safe. Concrete poles are NOT to be used in these locations where the separately earthed system is used as they will not meet touch potential safety requirements. Concrete poles can be used in “remote” locations, where the requirement for positive protection operation can be me, regardless of the method of earthing. Refer to document ENA C(b)1-2006 for definition of “locations”.

For specification details for Pre-stressed Concrete Poles, refer to Section CEM7102.05, and for Spun concrete Poles, refer to Section CEM7102.06 of the Overhead Construction Manual.

Sections of the South Western Region of Country Energy have established HV feeders where the installation of concrete poles is considered standard construction. A list of zone substation locations from which these HV feeders emanate are provided as follows:

• Narrandera • Hanwood

• Kywong • Tharbogang

• Yanco • Beelbangera

• Leeton • Griffith

• Coleambally • Warrawidgee

• Darlington Point • Carathool

• Ringwood Rd • Hay

• Egansford • Hillston

• Whitton • Ivanhoe

• Murrami • Wigelli

• Yenda • Cudgel

For further information on these locations contact the Manager Planning and Customer Connections – South Western Region at Country Energy Albury office.

c Steel Poles – steel poles may be used in “remote” locations where the requirement for positive primary protection operation can be met, regardless of the method of earthing. Refer to document ENA C(b) 1-2006 for definition of “locations”.

Steel poles shall not be used in seaside or estuarine areas known to be subject to salt pollution or in soils which are known to be chemically aggressive.

For specification details of Steel Poles, refer to Section CEM7102.08 of the Overhead Construction Manual.

When considering the use of conductive poles, the designer shall ensure that the insulation co-ordination of the structure is compatible with the existing network.


CE-IN-C

19 OctoApproved

CE-IN-C

MANUAL – OVERHEAD DESI

ONFIDENCE CEM7097

ber 2007 – Issue 3 By: Group Manager Standards and Demand Management

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ONFIDENCE UNCONTROLLED COPY IF PRINTED

3.5.9.5 Supplementary Fittings to Poles and/or Conductors

Supplementary fittings, in addition to the normal standard fittings, will be required as indicated in the following situations.

• Aerial inspection markers in accordance with EC guide for poles either side of any line crossing.

• Aircraft warning markers fitted to overhead lines in proximity of authorised landing sites and marking of overhead cable for low level flying in accordance with Australian Standard AS 3891.

• Sighters/bird diverters fitted to overhead conductors in the vicinity of known wildlife corridors to improve visibility of conductors.

• LV spacers to each span of bare overhead low voltage conductor in accordance with Clause 3.5.7.1. 3.5.10 Distribution Substations

Distribution Substations are to be constructed in accordance with the requirements set down in Country Energy document CEM7104 – Construction Standard Manual. Where a substation requires that a 200kVA or larger transformer be installed and the substation is shared by two or more customers, then Maximum Demand Indicators (MDIs) are to be installed on the structure. Distribution Transformer Fusing shall be in accordance with Country Energy’s document CEPG5099 – Distribution Transformer Fusing. Where a pole mounted substation is to be upgraded and the new transformer is of similar weight and physical size to that which is to be replaced and the pole has been inspected and found to be in a sound condition by Country Energy, then the substation pole will not need to be replaced. Only standard size transformers, listed as follows, are acceptable for connection to the network system.

GN





Standard Pole-Mounted Distribution Transformer – Refer to Country Energy’s Standard Construction Manual, Sections 7104-22 and 7104-23 for further details.

Single Phase Transformers Three Phase Transformers SWER Transformers

Country Energy Catalogue

No kVA Voltage

CE Specification

No CES5120.02

Country Energy

Catalogue No kVA Voltage

CE Specification

No CES5120.02

Country Energy

Catalogue No kVA Voltage

CE Specification

No CES5120.02

253700 16 11kV Item 2 254930 16 12.7kV Item 44.2 253940 16 22kV Item 15 255050 16 19.1kV Item 47.2253730 25 11kV Item 3 252110 25 11kV Item 7 254960 25 12.7kV Item 45 253970 25 22kV Item 16 252980 25 22kV Item 20 255110 25 19.1kV Item 48 254100 25 33kV Item 29 254120 25 33kV Item 30 253790 50 11kV Item 4 254970 50 12.7kV Item 46254030 50 22kV Item 17 255130 50 19.1kV Item 49

252200 63 11kV Item 8 253070 63 22kV Item 21 254140 63 33kV Item 31 252290 100 11kV Item 9 253100 100 22kV Item 22 254150 100 33kV Item 32 252410 200 11kV Item 10 253160 200 22kV Item 23 254160 200 33kV Item 33 252590 315 11kV Item 11 253250 315 22kV Item 24 254170 315 33kV Item 34 252740 500 11kV Item 13 253310 500 22kV Item 26 254180 500 33kV Item 35



19 October 2007 – Issue 3

3.5.11 Earthing

The design and construction of all earthing systems forming part of the works to be vested in Country Energy shall comply with Country Energy’s Construction Standard for Distribution System Earthing Document – CEM7109. All substations are required to have an accompanying electrode type earthing system suitable for its purpose. The earthing electrodes for pole-mounted substations are generally installed in a dedicated roadway or easement surrounding the pole base (if shared transformer on private property). Special earthing designs and segregation limits may be required in situations relating to swimming pools, communication centres, petrol and liquid fuel centres etc. For the principles of earthing, reference can be made to the Electricity Council of NSW document, EC5 ‘Guide to Protective Earthing’ and attention is drawn to the Energy Networks Association of Australia/Telstra document ‘Earth Mat Rise Code’. Where concrete poles are to be installed in “special” or “frequented” locations, a common multiple earth neutral (CMEN) system is required and ALL the concrete poles must be bonded to the LV neutral conductor or to a special CMEN conductor to ensure that they are touch safe. Conductive poles are NOT to be installed in “special” or “frequented” locations where the separately earthed system is used as they will not meet touch potential safety requirements. In locations where staff may be required to operate pole mounted equipment, the earthing should comply with the ENA document C(b)1-2006 clause 11.1.4, to the levels recommended for “Frequented” Locations. 3.5.12 Protection of Overhead Networks

3.5.12.1 High Voltage Overhead Networks

Protection of all overhead high voltage distribution feeders will be provided by Country Energy at the source substation by relays and circuit breakers and at positions along the feeder by reclosers and other protective devices in accordance with Country Energy document CEK8002 – Protection Guidelines. a 11kV/22kV Feeders These feeders will normally be provided with the following:

• 3-phase overcurrent

• earth fault

• instantaneous overcurrent and earth fault

• sensitive earth fault

• an earth fault indicator Reclosing will be provided at the source substation and initiated by all protection other than sensitive earth fault. Automatic reclose timing and automatic reclose attempts shall be in accordance with Country Energy document – CEK8002. Reclosing should be rendered non-operative during:

• Switching between feeders

• Live line work

• Tree trimming

• High fire danger days on bushfire designated feeders Back up protection will be provided by one of several options. This protection will improve limitations in the design of the feeder configuration as follows:

Approved By: Group Manager Standards and Demand Management of 37




19 October 2007 – Issue 3 Approved By: Group Manager Standards and Demand Management

• A minimum conductor size will be nominated by Country Energy for a particular feeder depending on fault levels, protective clearing times and load capacity. This also applies to any underground cable connected and to the cable sheath.

• A maximum feeder impedance will be specified by Country Energy to ensure minimum fault levels at feeder extremities are adequately detected by protection including back-up protection. All designs must account for these aspects and will be checked for compliance.

b Line Reclosers Pole-mounted line reclosers will be used in overhead distribution feeders where nominated by Country Energy. Line reclosers will be of a type complying with Country Energy’s specification and will provide protection, reclosing and remote control (SCADA) facilities. c Line Sectionalisers and Line Fuses Line Sectionalisers and line fuses may occasionally be used on 11kV and 22kV feeders but their use is kept to a minimum. 3.5.12.2 Protection of Low Voltage Overhead Networks

All 400/230V overhead bare conductor or aerial bundled conductor (ABC) networks are to be protected by current limiting HRC fuses at the distribution substation. Fuse types and application are to be in accordance with Country Energy’s Fuse Standard document – CEPG5099. The fuse size to be used will be nominated by Country Energy’s Planning and Customer Connection Manager for the region in which the installation is to be carried out and in accordance with the above documents. Note: CEPG5099 is not a public domain document. The maximum rating fuse to be used on an overhead low voltage network or distributor is 400A and all fuses shall be fast characteristic as defined in CEPG5099. Small rating distributor fuses shall be used in small transformer installations as defined in CEPG5099. There are limitations on the use of ABC conductors for protection reasons. The maximum impedance of LV network to the extremity of the ABC conductor is defined in Table 3.5.12.2 and associated notes.

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Max distributor length Fuse Size

Max loop impedance for the distributor 1 x 95 2 x 95 1 x 150

400A 160 + j32 mΩ 200m 400m 300m

250A 280 + j56 mΩ 350m 700m 530m

100A 720 + j144 mΩ 900m - 1360m

Table 3.5.12.2

Notes for Table 3.5.12.2:

1 Standard fuse sizes are in accordance with document CEPG5099.

2 The loop impedance of a LV distributor is defined as the total impedance, measured from a Distribution Centre to the network extremity, of a phase conductor plus the return neutral or other phase conductor.

3 The maximum distributor length is for protection limitations and does not take into account voltage drop considerations. That is, voltage considerations may considerably reduce the distributor length.

4 The intention is to clear the worst possible faults in approximately 10 seconds. Fuse clearing times are based on the slowest characteristic compatible with Country Energy’s specified bandwidth for fuse time-current characteristics.

5 The maximum distributor length provided in Table 3.5.12.2 could be exceeded for a particular situation provided that the 10 second clearing time is maintained.

6 The distributor lengths provided are based on the maximum loop impedance for a distributor with a constant cable configuration, i.e. 1 or 2 cables per phase for their entire length. Where a mixed configuration is used an equivalent proportional length can be used, eg, 200m of parallel 95mm2 cable plus 100m of single 95mm2 cable for a 400A fuse (see figure 1 below).

Figure 1 – Mixed Cable Configuration

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3.5.13 Insulation Co-Ordination

In general, Country Energy’s overhead line designs and standards are based on co-ordinated levels of insulation withstand voltages for the various line configurations and equipment types together with the correct application of surge arresters. Failure performance of the installation is very adversely affected by seemingly minor departures from construction standards affecting clearances or configuration. The basic insulation coordination principles as outlined in Australian Standard AS1824.1 and the guidelines as set out in AS1824.2 should be applied to all overhead lines and associated equipment. It is important that all material and equipment installed on the network comply with the appropriate Country Energy Specification. Principles to be followed are:

• Every pole substation to have surge arresters at the transformer HV terminals

• Every HV underground to overhead connection shall have surge arresters fitted

• All surge arresters must comply with Country Energy’s specifications and AS1307 and shall in particular comply with the specification in respect to:

• Spark performance

• Shattering performances

• Surge arresters are to be installed on both the source and load side of line reclosers, sectionalisers and gas switches

• No surge arresters are to be installed at inline air break switch or link locations

• Earthing systems shall comply with the requirements as shown in Country Energy’s Construction Manual CEM7109, Distribution Overhead Mains

• Pin insulators on timber crossarms are not to be bonded together (as this reduces BIL and does not take advantage of the arc-quenching properties of timber)

• All 11kV lines shall be constructed with 22kV insulation

• Additional insulation is required for 22 and 33kV lines constructed within 3km of the ocean or large areas of salt water including bays, inlets and lakes, or where insulators are attached to earthed/conductive poles and crossarms

3.5.14 Special Requirements of Other Authorities

As previously indicated in Clause 3.2 of this document, it is the responsibility of the designer to obtain approvals as necessary from other relevant authorities prior to construction. As a general requirement, all crossings of rail lines, waterways, TransGrid undercrossings and overhead lines near aircraft landing fields MUST be profiled. Country Energy will assist in the approval process by submitting the application with the basic information as provided by the ASP. Basic requirements are as follows:

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3.5.14.1 Rail Crossings

Where an overhead extension or augmentation project involves the crossing of a railway line or railway property, the designer shall be responsible for providing a separate crossing plan with profile, a completed Electrical Aerial Crossing data sheet and where necessary a request for underground services on Rail Infrastructure Corporation (RIC) property, in accordance with RIC document EP10 01 00 05 SP. The Regional Office of Country Energy for the region in which the rail crossing will occur will submit the application on behalf of the ASP for approval by the RIC. Note: Low voltage (230/400V) aerial crossings of electrified tracks are NOT permitted. 3.5.14.2 Crossings of Waterways

Similar to Rail Crossings, the designers shall prepare a separate drawing with profile of the waterway crossing suitable for submission to the Waterways of NSW. The plan and profile shall include all details of the crossing such as pole heights, pole locations in relation to the waterway, the relative levels of pole, conductor sag and clearance relative to high water levels (HWL) at maximum design operating temperature. The Regional Office of Country Energy for the region in which the Waterways crossing is to be located will prepare and submit the application on behalf of the ASP to the Waterways Authority. 3.5.14.3 TransGrid Undercrossings

Similar to Clause 3.5.14.1 the designer shall prepare a separate drawing of all undercrossings of TransGrid lines. The drawing shall provide a plan and profile showing details of the poles and conductor heights and location of the undercrossing in relation to TransGrid conductors and structures. Reference is made to TransGrid drawing A3 TL613883 for the clearance requirements. The height of TransGrid conductors should indicate the time, the day, month and year and the ambient temperature at which the measurement was taken with appropriate notation of any wind condition present at the time. The maximum height of Country Energy lines shown on the profile shall be the minimum designed operating temperature of the line. Country Energy’s Office for the Region in which the undercrossing occurs will assist with the submission of the approval application when the ASP has provided the information previously outlined. 3.5.14.4 Overhead Lines near Aircraft Landing Fields Designers should be aware that overhead power lines shall not encroach on glide paths adjacent to aircraft landing field. Glide path dimensions are provided in Civil Aviation Authority Publication CAAP92-1(1), 1998. Fitment of aircraft warning marker balls to conductors of lines located near aircraft landing fields may be required, refer to Clause 3.5.9. Designers should increase the wind loading on conductors accordingly.

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3.5.14.5 Co-ordination of Power and Telecommunications

Guidelines for the co-ordination of power systems and cabled telecommunication system requirements are provided in Standards Australia document HB100-2000(CJC4) Co-ordination of Power and Telecommunication. It is a requirement that all designs comply with the true spirit and intent of the aforementioned guidelines.

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AATTTTAACCHHMMEENNTT AA –– LLOOAADD TTYYPPEE AANNDD VVAALLUUEESS

Region Load Type ADMD Standard Deviation

Ratio Customer Utilisation Factor

for Transformer Sizing

All Units and Relocatable Homes 3.0kVA/dwelling 1.0 No. of

Customers Utilisation Multiplier

Prestige Units, Integrated Housing 3.5kVA/dwelling 1.0 1 2.0

Rural Estates 7.0kVA/lot 1.0 2 1.60

Rural domestic 5.0kVA/dwelling 1.0 3 1.47

Light Industrial Estates** 30.0kVA/lot** 0 4 1.40

Pumps and Motors Actual Rating 0

Coast Residential* 4.0kVAlot* 1.0 5 1.36

Coast Prestige Housing, Canal Estates, Village Residential

5kVA/lot 1.0 10 1.25

Inland Prestige Residential – no reticulated gas*** 7.5kVA/lot*** 1.0

Inland Residential – no reticulated gas 6.0kVA/lot 1.0

20 1.10

Inland Residential – reticulated gas 4kVA 1.0

Inland Prestige Residential reticulated gas 5.5kVA 1.0

30 1

* Includes Duplex Lots ** Use 30kVA or actual known loading, whichever is greater *** In some prestige Alpine residential subdivisions or in other specific locations, it may be prudent to

use an ADMD greater than 7.5kVA/lot. In such cases the actual ADMD used will be identified in the preliminary design information.

In addition to the previous load information, when calculating voltage drops using “LVDROP” (version 5.48 or later) software, the following parameters should also be used.

Transformer: LOIMP Voltage:

Source = 240V Nominal = 230V

Confidence Factors for Overhead Systems: Voltage Drop = 3.00 Conductor Loading = 2.00

Transformer sizing use Utilisation Factor Table above. Method Statistical POA All Point of Application factors are to be calculated Load Power Factor: Use 0.9 if not known Node 3 phase total load: Use unbalanced multiplier of 1. Node single phase: Use twice (2x) the distance as per the software instructions.

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SIZING OF TRANSFORMERS: Where customer loads are not assessed using AS3000 and the tabulated ADMD values are used, then the utilisation multiplier must be used in assessing the transformer capacity for the required number of customers. TRANSFORMER SIZE = ADMD x NUMBER OF CUSTOMERS x UTILIZATION FACTOR As a general rule, the transformer size obtained using this method should be in the order of 50% of the value that would be obtained using the total load current shown in the LVDROP program.

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AATTTTAACCHHMMEENNTT BB -- LLOOAADD DDEENNSSIITTYY VVAALLUUEESS FFOORR AASSSSEESSSSMMEENNTT OOFF MMAAXXIIMMUUMM DDEEMMAANNDD Typical Load Density Values (VA/m2) for different types of Floor Area Usage (Net Areas) These load density values depend on many factors including:

• the effects of the outside environment on the building structure and type of air conditioning system

• the effects of heat or electrical equipment loads within the premises

• the proposed lighting design and

• the degree of environment control and load management within the premises. The average values may be used where insufficient information is available.

Type of Development Range VA/m2

Average VA/m2

Offices Not air conditioned 40-60 50 Air conditioned – cooling only 70-100 85 Reverse Cycle 60-90 75 Electrical reheat open areas 80-120 100 Electrical reheat zonal or package units 90-130 110 Variable volume 60-80 70 Car Parking Open air 0-10 5 Ventilated 10-20 15 Warehousing Unventilated 5-15 10 Ventilated 10-20 15 Shops Not air conditioned 40-100 70 Air conditioned 60-140 100 Shopping Centres (assumed air conditioned shops) Not air conditioned public areas 60-140 100

Air conditioned public areas 80-160 120 Industrial Light 10-20 15 If ventilated add 10-20 15 If air conditioned add (see note) 30-50 40 Theatres, halls, etc Ventilated 50-70 60 Air conditioned 80-120 100 Hotels, taverns, restaurants 60-100 80

Note: Medium and heavy industrial areas require full details of connected load before an assessment of

demand can be made. Only uniformly distributed loads such as lighting and air conditioning can be assessed using this area usage method.

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AATTTTAACCHHMMEENNTT CC -- CCOONNDDUUCCTTOORR IINNFFOORRMMAATTIIOONN

Impedance values show in the following conductor information table are provided for calculating purposes only and should be used when assessing existing networks for interconnection with new developments using standard conductors. In general, the impedance R and X components and the conductor ratings are extracted (where available) from the Australian/New Zealand Standard AS/NZS 3008.1.1:1998. Generally resistance values are for a conductor temperature of 75°C and the Reactance values are for LV conductor spacing of 0.6m at 50Hz. The current carrying capacity of the conductors shown are generally based on an ambient temperature of 40°C and a maximum conductor temperature of 75°C with a wind speed of 1m/s. The values shown in the following table generally align with those provided in the Country Energy version of “LVDROP”.

CONDUCTOR INFORMATION TABLE

Resistance Reactance Rating Description Conductor size

And type ohm/km ohm/km Amp [AAAC-4W]

19/3.25AAAC 0.22544 0.29063 473 19/3.75AAAC 0.17123 0.28166 562 19/4.75AAAC 0.11061 0.26684 747 37/3.00AAAC 0.13846 0.27389 642

3Ø 4 WIRE LV ALL ALUMINIUM ALLOY BARE OVERHEAD CONDUCTOR 7/2.50AAAC 1.01631 0.34195 184 7/3.00AAAC 0.70735 0.33049 234 7/3.75AAAC 0.45175 0.31619 307 7/4.50AAAC 0.31505 0.30501 383 7/4.75AAAC 0.28307 0.3014 409 [AAC-4W]

19/.128AAC * 0.21817 0.2908 479 19/.149AAC * 0.16299 0.28126 570 19/3.25AAC 0.21937 0.29063 479 19/3.75AAC 0.16602 0.28183 570

3Ø 4 WIRE LV ALL ALUMINIUM BARE OVERHEAD CONDUCTOR 19/4.75AAC 0.10776 0.26684 756 37/3.00AAC 0.13541 0.27389 651 7/.118AAC * 0.68367 0.33055 237 7/.134AAC * 0.53037 0.32256 274 7/.144AAC * 0.43859 0.31821 311 7/.173AAC * 0.31943 0.30651 388 7/1.75AAC 2.02037 0.36437 139 7/2.50AAC 0.98472 0.34195 190 7/3.00AAC 0.68485 0.33049 237 7/3.75AAC 0.43859 0.31619 311 7/4.50AAC 0.3071 0.30501 388 7/4.75AAC 0.27615 0.3014 413 * Existing Imperial Size Conductors

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CONDUCTOR INFORMATION TABLE (contd)

Resistance Reactance Rating Description Conductor size

And type ohm/km ohm/km Amp [ACSR-4W]

3/4/.0661 * 4.22584 0.39528 85 3/4/.093 * 2.22801 0.37382 131 3/4/1.75 4.06991 0.39208 85 3/4/2.50 1.99131 0.37026 131

3Ø 4 WIRE LV ALUMINIUM CONDUTOR STEEL REINFORCED 4/3/3.00 1.16642 0.34834 91 4/3/3.75 0.74553 0.33404 238 6/1/.093 * 1.41429 0.34656 167 6/1/.118 * 0.87852 0.33159 209 6/1/.144 * 0.59083 0.31908 274 6/1/2.50 1.2674 0.343 167 6/1/3.00 0.88034 0.33154 209 6/1/3.75 0.56387 0.31752 274 6/4.75+7/1.60 0.36364 0.30244 364 [HDBC-4W]

19/.064HDBC * 0.54705 0.34839 270 19/.083HDBC * 0.32147 0.31802 337 19/.101HDBC * 0.21753 0.30569 552

3Ø 4 WIRE LV HARD DRAWN BARE COPPER CONDUCTOR 19/1.75HDBC 0.4643 0.32973 286 19/2.00HDBC 0.35679 0.32134 337 19/3.00HDBC 0.16103 0.29586 552 7/.064HDBC * 1.44252 0.369 156 7/.080HDBC * 0.92372 0.35498 183 7/.104HDBC * 0.54705 0.33849 270 [ABC-2W]

25ABC/2c 1.41762 0.089 105 1Ø 2 WIRE LVABC 95ABC/2c 0.37863 0.08 230 [ABC-4W]

25ABC/4W 1.41762 0.097 97 3Ø 4 WIRE LVABC 50ABC/4W 0.75725 0.093 140 70ABC/4W 0.52418 0.088 175 95ABC/4W 0.37863 0.087 215 150ABC/4W 0.24449 0.084 280 [Al U/G-4C]

120A/4C 0.31 0.0685 255 185A/4C 0.202 0.0686 325 240A/4C 0.154 0.0678 380

3Ø 4 CORE LV SECTOR SHAPED ALUMINIUM UNDERGROUND CABLE [Cu U/G-4C]

16C/4C 1.4 0.0861 105 25C/4C 0.884 0.0853 150 50C/4C 0.471 0.0797 215

3Ø 4 CORE LV CIRCULAR SHAPED COPPER UNDERGROUND CABLE * Existing Imperial Size Conductor

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4 REFERENCES

CECG1000 – Safety, Health and Environmental Management

CEFD6024 – Environmental Assessment

CEK8003 – Subtransmission and Distribution Network Planning Criteria and Guidelines

CEK8042 – Distribution Apparatus Node Number Plates and Operational Number Labelling

CEK8046 – Easement Requirements

CEM7001 – Construction Drawing Standard Symbology

CEM7011 – Standard Overhead Conductor Current Rating Guide

CEM7063 – Information Security Sensitivity Handling

CEM7098 – Construction Standard Manual – Underground Design

CEM7099 – Standard Overhead Construction Manual

CEP2010 – Vegetation Clearing Guidelines for New Power Lines

CEPG1096 – Information Security Sensitivity Labelling and Handling

CEPG2016 – Environmental Impact Assessment

CEPG2021 – Removing Vegetation near Overhead Powerlines

CEPG2162 – Policy Document Management

CEPG5099 – Distribution Transformer Fusing

CEPG5124 – Full Length Preservative Treated Hardwood Poles

CEPG8002 – Protection Guidelines

CEPG8008 – Vegetation Management Plan

CEPG8019 – Capital Contributions

CEPG8022 – Bush Fire Risk Management Plan

CEPG8040 – Corporate Purchasing

AS1158 – Australian Standard Publication – Road Lighting Operation and Maintenance

AS1307 – Australian Standard Publication – Surge Arrestors

AS1824.1 – Australian Standard Publication – Insulation Co-ordination

AS3000 – Australian Standard Publication – Wiring Rules

AS/NZS 3008.1.1 – Electrical Installation – Selection of Cables

AS61000 – Australian Standards Publication – Electromagnetic Compatibility (EMC)

CAAP92-1(1),1998 – Civil Aviation Authority Publication

EC5 – Electricity Council of NSW – Guideline to Protective Earthing

EP10 01 00 05 SP – Rail Infrastructure Corporation Requirements for Electric Aerials Crossing RIC Infrastructure

ENA C(b)1-2006 – Energy Networks Association Publication ‘Guidelines for Design and Maintenance of Overhead Distribution and Transmission Lines’

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HB100-2000(CJC4) – Australian Standard Publication – Co-ordination of Power and Telecommunications

ISSC20 – Industry Guidelines for the Management of Electricity Easements

Environmental Planning and Assessment Act 1979

Service and Installation Rules of New South Wales, 2006

Independent Pricing and Regulatory Tribunal Determination No. 1, 2002

Community Land Development Act 1989

OHS Act 2000 and OHS Regulation 2001

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5 REVISIONS

This document shall be reviewed in accordance with Country Energy policy document CEPG2162 – Policy Document Management, as a minimum requirement.

Issue Number Section Details of Changes in this Revision 1 Para 2 updated to include all CE documents, and also Acts and

Regulations

1 Para 3 added

3.4 Sentence “The gas switch is the standard switch to be used on the Country Energy distribution network” added

3.5 “This document” and CECG1000 added as bullets

3.5.5 & 5 CEK8042 no longer in draft

3.5.6 Now includes CEM7099

3.5.6.6 CEM7106.27 added

3.5.6.7 Table

2nd Column, 3rd Row now ACSR or AAAC

2nd Column, 4th Row now AAAC

3.5.7.1 Table

4th Column, 2nd Row now CES5104.17

4th Column, 3rd Row item 1 added

4th Column, 4th Row now CES5104.23 item 2

4th Column, 5th Row now CES5104.23 item 3

3.5.8 HBC(b)1-2003 now ENA C(b)1-2006

3.5.9.3 “All pole substations shall be positioned in a location that allows access at all time, by a borer/erector” Added to para 1

3.5.10 & 5 CEPG5099 – Distribution Transformer Fusing now doc # CEPG5099 still Draft

5 CECG1000, CEK8022, CEPG2162 & OHS Act & Regulation added

CEP2016 now CEPG2016

Various Electricity Supply Association of Australia Limited (ESAA) now Energy Networks Association (ENA)

2

Various ESAA.C(b)1-2003 now ENA C(b)1-2006

3.2 Insertion above last paragraph.

3.5.1 Changes to the second paragraph

3.5.6.3 ‘Consumers terminals’ changed to ‘Point of Supply’

3.5.8 Change of C(b)1-2006 to ENA C(b)1-2006

3.5.9.2 Revised wording in first and fifth paragraphs

3.5.9.3 Additional wording in first paragraph “a minimum clear space…at the site”

3.5.9.4 Various changes

3.5.10 Removal of draft for CEPG5099 and change rural substation to pole mounted.

3.5.11 Insertion at the end of the section

3

4 CEPG5124 added.

Updated title – Service Installation Rules of NSW 2006

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