Branch Procedure NETWORK Document No Amendment No Approved By : : : Approval Date Review Date : : CEOP8032 8 Manager Project Development 15/05/2014 01/11/2014 Supersedes Document CEOP8032 Amendment 7 CEOP8032 Transmission and Zone Substation Design Guidelines DISCLAIMER 1 Essential Energy may change the information in this document without notice. All changes take effect on the date made by Essential Energy. A print version is always an uncontrolled copy. Before using this document, please check that it is still current. 2 This document may contain confidential information. Restrictions on the use and disclosure of confidential information by employees are set out in your contract of employment. Restrictions on the use and disclosure of confidential information by contractors are set out in your contract of engagement with Essential Energy. Subcontractors are bound by the confidentiality provisions set out in their contract with the contractor engaged by Essential Energy. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 1 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 CONTENTS 1.0 PURPOSE............................................................................................................................ 4 2.0 SCOPE ................................................................................................................................ 4 3.0 REFERENCES ..................................................................................................................... 4 4.0 DEFINITIONS ...................................................................................................................... 5 5.0 ACTIONS ............................................................................................................................. 8 5.1 Design work packs ............................................................................................................ 8 5.2 Substation design scope ................................................................................................... 8 5.2.1 General...................................................................................................................... 8 5.2.2 Preliminary design drawings ...................................................................................... 8 5.2.3 Project/site specific information.................................................................................. 9 5.3 Civil & Structural Design ................................................................................................... 9 5.3.1 General...................................................................................................................... 9 5.3.2 Finished levels ......................................................................................................... 10 5.3.3 Substation set out lines ............................................................................................ 10 5.3.4 Substation benchmark ............................................................................................. 10 5.3.5 Earthworks design ................................................................................................... 10 5.3.6 Roadway design ...................................................................................................... 10 5.3.7 Footing design ......................................................................................................... 11 5.3.8 Transformer oil containment .................................................................................... 11 5.3.9 Fence layout ............................................................................................................ 12 5.3.10 Drainage of switchyard ............................................................................................ 12 5.3.11 Water supply............................................................................................................ 12 5.3.12 Deluge safety showers............................................................................................. 13 5.3.13 Earthing design ........................................................................................................ 13 5.3.14 Conduits, trenches and pits ..................................................................................... 14 5.3.15 Landscape design.................................................................................................... 15 5.3.16 Structural Steelwork Design ..................................................................................... 15 5.4 Building design ............................................................................................................... 15 5.4.1 General.................................................................................................................... 15 5.4.2 Performance criteria ................................................................................................ 16 5.4.3 Fire risk & fire resistance level ................................................................................. 17 5.4.4 Type 1 - two story masonry switchboard and control building with cable basement . 18 5.4.5 Type 2 - single story masonry switchboard and control building with cable pit ......... 21 5.4.6 Type 3 - prefabricated switchboard building, mounted on piers with cable basement 22 5.4.7 Type 4 - prefabricated control building placed at ground level with cable pit ............ 23 5.4.8 Masonry buildings design criteria (Type 1 & 2)......................................................... 25 5.4.9 Prefabricated buildings design criteria (Type 3 & 4) ................................................. 25 PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 2 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES 5.4.10 5.5 Amendment No: 8 Building services ...................................................................................................... 26 Primary system design.................................................................................................... 27 5.5.1 General.................................................................................................................... 27 5.5.2 Primary system design drawings ............................................................................. 28 5.5.3 Clearances .............................................................................................................. 29 5.5.4 Lightning impulse withstand voltage level ................................................................ 29 5.5.5 Primary system equipment ...................................................................................... 29 5.6 Secondary system design ............................................................................................... 32 5.6.1 General.................................................................................................................... 32 5.6.2 Low voltage and control cabling ............................................................................... 33 5.6.3 Cable ladder ............................................................................................................ 34 5.6.4 Control and protection panels .................................................................................. 35 5.6.5 Protection links and wiring ....................................................................................... 36 5.6.6 Fuses....................................................................................................................... 36 5.6.7 Control panel labels ................................................................................................. 37 5.6.8 Standard wiring code ............................................................................................... 37 5.6.9 Moulded Case and Miniature Circuit Breakers ......................................................... 37 5.6.10 Indication and control equipment ............................................................................. 37 5.6.11 SCADA .................................................................................................................... 38 5.6.12 Transformer voltage regulation ................................................................................ 39 5.6.13 VT supply changeover scheme ................................................................................ 39 5.6.14 Substation metering ................................................................................................. 39 5.6.15 CT and VT secondary connections .......................................................................... 39 5.6.16 Substation auxiliary AC supply................................................................................. 40 6.0 RECORDKEEPING ............................................................................................................ 41 7.0 AUTHORITIES AND RESPONSIBILITIES ......................................................................... 41 8.0 DOCUMENT CONTROL .................................................................................................... 42 PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 3 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES 1.0 Amendment No: 8 PURPOSE The purpose of the Transmission and Zone Substation Design Guidelines is to achieve a satisfactory and consistent design approach for all Essential Energy’s substations. This guideline shall be used by substation design employees and design consultants involved in the design of the company’s transmission and zone substations. The specific requirements in this guideline have been adopted by the company to standardise the design, procurement, construction and maintenance of its substations. 2.0 SCOPE All substation design shall be carried out in accordance with these guidelines, Australian Standards and other relevant standards, technical guides and any other interrelated company policies or procedures. The development of transmission, sub-transmission and zone substation designs must deliver achievable outcomes that are balanced with: employee safety public safety environmental considerations quality performance maximizing reliability cost reduction protection of system assets. 3.0 REFERENCES Internal: CEOS5036 – Zone Substation: Intruder Resistant Fencing and Associated Works – Specification CEOM7051.08 - Substation design reference manual: substation busbars CEOM7051.15 - Substation Design Reference Manual: Standard Wiring Code CEOM7051.19 - Substation Design Reference Manual: Device Function Numbers CEOM7051.23 - High Voltage A.C. Transmission and Sub-Transmission Station: Earthing Techniques CEOM7051.24 - Substation Design: Electrical Clearances CEOM7051.135 - Substation Design Reference Manual: Structural Steelwork CEOM7052 - Zone Substation Design Services: Drawing Guidelines CEOM7306 – Zone Substation: Intruder Resistant Fencing Drawings – Index CEOP8002 - High Voltage Protection Guidelines CEOP8042 – Networks: Asset Identification & Operational Labels CEOP8084 - Design guidelines for SCADA and DSA CEOP8085 – Load Control: Design Guidelines External: BCA - Building Code of Australia AS1033 High-voltage fuses (for rated voltages exceeding 1000V) AS/NZS 1170 Structural design actions AS/NZS 1554 Structural steel welding AS1627 Metal finishing - preparation and pre-treatment of surfaces AS/NZS 1665:2004 Welding of Aluminium Structures AS1726-1993 Geotechnical site investigations AS/NZS 1768:2007 lightning protection AS1824 Insulation co-ordination PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 4 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 AS1940-2004 The storage and handling of flammable and combustible liquids AS2005 AS2024 High voltage a.c. switchgear & control gear – Switch fuse combinations AS/NZS2053.2-2001Conduits and fittings for electrical installations – Rigid plain conduits and fittings of insulating material AS2067 Substations and high voltage installations exceeding 1kV AC AS2184 Low voltage switchgear and control gear - moulded case circuit-breakers for rated voltages up to and including 600 V ac and 250 V dc) AS 2374 Power transformers AS2629 Separable insulated connectors for power distribution systems above 1 kV AS2650 Common specifications for high-voltage switchgear and control gear standards AS 2676 Guide to the installation, maintenance, testing and replacement of secondary batteries in buildings - vented cells AS2870-2011 Residential slabs and footings AS/NZS 3000 SAA wiring rules AS/NZS3008 Electrical installations - selection of cables AS 3011.1 Electrical installations - secondary batteries installed in buildings - vented cells AS/NZS3111 Approval and test specification for miniature overcurrent circuit-breakers AS/NZS3190 Approval and test specification - residual current devices (current-operated earthleakage devices) AS3600-2009 Concrete structures AS3610-1995 Formwork for concrete AS3700-2011 Masonry structures AS3850-2003 Tilt up concrete construction AS4100-1998 Steel structures AS/NZS60269.1-2005 Low voltage fuses – General requirements AS60947.5.1-2004 Low-voltage switchgear and control gear – Control circuit devices and switching elements – Electromechanical control circuit devices AS62271.301-2005 High voltage switchgear and control gear – Dimensional standardization of terminals IEC60050-445 International Electrotechnical Vocabulary – Part 445: Time Relays 4.0 DEFINITIONS Document control Employees who work with printed copies of document “uncontrolled if printed”, as indicated in the footer. Recordkeeping Making and maintaining complete, accurate and reliable evidence of business transactions in the form of recorded information (Source: AS records classification handbook – HB5031 – 2011.) Review date The review date displayed in the header of the document is the future date for review of this document. The default period is three years from the date of approval however a review may be mandated at any time where a need is identified due to changes in legislation, organisational changes, restructures, occurrence of an incident or change in technology or work practice. A Ampere, unit of electrical current AC Alternating current AAC All aluminium conductor PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 5 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 AAAC All aluminium alloy conductor Al Aluminium BBP Busbar protection BCA Building Code of Australia BMT Base metal thickness BSP British standard pipe CT Current transformer Cu Copper DC Direct current DIN DIN rail is a metal rail of a standard type widely used for mounting circuit breakers and industrial control equipment inside equipment racks. Essential Energy Referred to as ‘the company’ throughout the document. FDR Feeder FI Frequency injection FRP Fibre reinforced polymer FSL Finished surface level GA General arrangement GL Ground level GPO General purpose outlet PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 6 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 GVM Gross vehicle mass HV High voltage I/O Inputs and outputs Kg Kilogram kPA Kilopascal kV Kilovolts, unit of electrical voltage LED Light emitting diode, used in indication lamps LV Low voltage mA Miliampere, unit of electrical current mm Millimetre MPa Mega pascal PLC Programmable logic controller PVC Polyvinyl chloride RCD Residual current device REF Review of environmental factors SCADA Supervisory Control and Data Acquisition SEF Sensitive earth fault TOC Top of concrete UTP Unshielded twisted pair PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 7 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 V Volt, unit of electrical voltage VT Voltage transformer XLPE Cross linked polyethylene 5.0 ACTIONS The Design Guidelines are outlined below: 5.1 Design work packs The substation design work packs have been separated into five (5) sections: substation design scope; civil and structural design; building design; primary system design; and secondary system design. All drawings shall be in accordance with the company’s drawing guidelines CEOM7052. 5.2 Substation design scope 5.2.1 General The substation design group shall provide a project brief for a design project detailing the overall objectives and delivery schedule. The brief shall be used to prepare and collate the substation design scope. The design scope is the first step in the design process and is a formal hold point to determine if the project goals, time frame and costs are achievable. The design scope is also used to ensure that all the relevant information is available to complete the detailed design. The substation design scope documents for each project shall include preliminary design drawings, project/site specific information and the substation design scope checklist. The checklist is a document that records the source and date for information received and highlights any areas that may cause issues during the design phase of the project. The preparation of the scope information will involve liaising with the various company departments and may include communicating with other organisations such as Transgrid, local councils and state government departments. 5.2.2 Preliminary design drawings The preliminary drawings depict the key design decisions for each design project. Typically the following drawings shall be produced: single line diagram; general arrangement (GA) - plan view; site plan; protection single line diagram; phasing diagram – if available; SCADA schedule – preliminary; and PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 8 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 building floor plans. 5.2.3 Project/site specific information Information relating to the following areas if applicable shall be collated: environmental assessments; 1 in 100yr flood levels; building requirements; revenue metering; security; communications; load control requirements; surveys; fault level reports; protection design information; subtransmission line information; distribution line Information; geotechnical reports; earthing reports; major equipment schedules; and drawing schedules. The substation design group has developed standard templates detailing the information required for geotechnical reports and survey information. 5.3 Civil & Structural Design 5.3.1 General The civil design package shall be designed in accordance with the relevant Australian Standards and reference shall be made to the conditions and or control measures detailed in the environmental assessment. The following site and civil design drawings shall be produced: earthworks; access roads; footings; steelwork; oil containment and treatment; hydraulic services; drainage; fence layout; conduit & pit layout; earth grid layout; and landscaping. The civil design needs to ensure that the substation can effectively withstand a 1 in 100yr flood or major storm event without significant damage. Typically all control cubicles for the yard equipment and the buildings floor level must be designed and constructed a minimum of 500mm above the expected flood levels. For high rainfall and coastal areas, the level of may need to be considered to cater for extreme storm and higher than normal water levels. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 9 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES 5.3.2 Amendment No: 8 Finished levels The substation design group requires the following standard terminology to be used on all civil design drawings to clearly identify the designed levels. Ground Level (GL) - finished ground level including compacted subgrades; Finished Surface Level (FSL) - finished surface level of site – for switchyard areas, top of blue metal in switchyard; and Top Of Concrete (TOC) - reference level for footings – to be shown on relevant footing drawings. 5.3.3 Substation set out lines All substation layouts and equipment dimensioning shall be referenced to set out lines. The lines shall be placed on the rear of the kerb of the access road and along the centreline of the first bay. 5.3.4 Substation benchmark The location of survey benchmarks shall be shown on earthworks and site plans. The benchmarks shall be utilised to locate the substation area on the parcel of land and provide a local reference level. 5.3.5 Earthworks design The earthworks design shall include but not be limited to, drawings and information detailing the site clearing, excavation, benching, compaction of the entire site, final levelling and surfacing, Access roadways and erosion control. The design of the switchyard area shall include a capping layer of road base for all weather access. Unless otherwise stated in the design scope the final surface of the switchyard shall be designed with optimum fall of 1%. 5.3.6 Roadway design Access Roadway Design The substation access road shall be designed to allow for easy access for construction and maintenance vehicles at all times and shall be designed to approved Roads and Maritime Services and/or local council parameters. The access road shall be designed with a minimum width of 5 metres excluding any kerb or guttering and at bends or curves. The minimum road finish shall be gravel. The road design shall include stormwater drainage design. The use of the full width of the access road shall not be restricted by fences or gates. Where possible; parking areas shall be designed to accommodate 3 standard cars and a single 15 tonne GVM rigid vehicle outside the substation. Switchyard Internal Roadway Design The substation internal roadways shall be designed to allow efficient replacement of transformers and /or emergency access for works in the switchyard. The level of the finished roadway shall be as close to the level of the transformer footing as possible to enable easy unloading of transformers. Cable and drainage conduits shall be installed prior to construction of access roads. Conduits are to be located in excess of 50 mm below the compacted sub-grade and suitably protected to ensure no duct deformation under any conditions. The preferred design incorporates concrete edging constructed at the same level as the finished road surface in preference to traditional kerb and gutter. The roadway is then sloped to the centre to provide drainage. A concrete beam is to be installed under the gateway. The road surface shall be hot mix bitumen as shown on the typical roadway designs, unless otherwise stated in the project definition. The road levels at the gate must allow the double gates to PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 10 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 open inwards into the switch yard. The internal roadways shall be designed with a minimum width of 6 metres excluding any edging, kerb or guttering and at bends or curves. The kerb, edging and roadway design must ensure the clearance under the security gates is kept to a maximum of 50mm. The addition of a speed hump to achieve the required clearance will not be accepted. Minimum Requirements for road design Item Minimum Requirement Load to be supported 100 tonnes Concrete edging (bitumen road) 200 mm wide x 300 mm deep (reinforced) Maximum access road gradient 1:15 or 4 degrees Minimum access road turning 15 metres inside radius Minimum Turning Circle Item Minimum Requirement Construction trucks 5 metres inside radius Low loaders 15 metres inside radius Maximum deviation of concrete 10 mm over 3 metres 5.3.7 Footing design The substation design group has developed a suite of template footing design drawings and shall be replicated as required. All the footing designs are to be assessed as suitable for the specific situation and soil conditions. Information and recommendations from the geotechnical assessment shall be used to review and certify each footing design. If a suitable footing is not provided in the suite of drawings, a design shall be produced and certified. It is preferable that consistent methods of construction and standard rag bolt assemblies are used. In general, pier type footings are preferred to slab footings due to the reduced construction costs. A footing layout drawing shall be produced to provide the location and reference level information for the construction of all the footings. 5.3.8 Transformer oil containment All transformers are to be installed with facilities to contain any oil spillage in the event of a tank failure. The containment facility shall be sufficient to contain at least 2 times the main tank oil volume. Bund walls shall be constructed on the concrete slab that forms part of the transformer foundation. No oil shall be allowed to leech into the soil below the bund. Oil containment is to be in accordance with AS2067. The transformer bund size and height shall be designed in accordance with AS1940 section 5.8 and appendix H. Oil water separation systems shall be designed and installed at each substation. The type and specific requirements shall be determined in the project definition. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 11 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 Where a concrete oil water separation tank is installed the water overflow from the tank is to undergo suitable treatment within the property boundaries of the substation site using an appropriate secondary filtration process. This is to ensure full compliance with local council along with regulatory and legislative requirements. The type of secondary filtration process to be employed is to be detailed in the project definition. The final location within the substation site and the design of the secondary system is to be completed as part of the detailed design. A transformer footing and bund design drawing shall be produced detailing the information and materials required to construct the footing and bund. The footing layout drawing shall provide the location and reference level information for the construction of the transformer pad and bunding. The installation of the oil water separator and associated pipe work shall be included on the drainage layout drawing. The transformers shall generally be separated by a minimum distance of 10 metres for 66kV and below and 15 metres for 132kV. If these distances cannot be met a blast wall shall be constructed between the transformers. The blast wall shall be designed as per the requirements of AS2067. 5.3.9 Fence layout Substation security fences shall comply with CEOS5036 - Zone Substation: Intruder Resistant Fencing & Associated Works - Specification. The fence details are also shown on a suite of standard fence assembly drawings; refer to CEOM7036 – Zone Substation: Intruder Resistant Fencing Drawing Index. The purpose of the fence layout drawing is to detail the arrangement of the substation high security fence and all vehicle and personal access gates allowing for accurate procurement of materials and installation. The fence and gates are to be dimensioned from the set out lines and all levels to top of concrete mowing strip footing to show gradient of fence. 5.3.10 Drainage of switchyard The switchyard shall have a subsurface drainage system installed to remove excess water from the site and the site shall be contoured in such a manner as to remove hollows, which may retain water and cause ponding. All drainage water shall be collected in adequately sized drains to a suitable off site discharge point in a manner that complies with all relevant NSW government departments, local council and water authority regulations. Reference shall be made to the environmental assessment and/or review of environmental factors (REF) to ensure that all issues are addressed. Building basements, cable pits and trenches shall be drained to the storm water system. A drainage layout drawing shall be produced to provide the location and reference level information for the construction of all drainage systems. 5.3.11 Water supply Each substation requires a secure water supply for amenities, cleaning and for emergency situations such as fires and equipment failures. The project definition documents shall indicate the requirements for the water supply. Generally the substation is connected to the mains water supply or on site water storage tanks are provided. Requirements for connection to mains water supply A minimum 32 mm service is to be installed between the water authority’s service main and the substation shut-off valve/meter. Thereafter, 40mm polyethylene shall be installed to provide the necessary electrical isolation of the mains water supply from the substation. A separate unmetered fire service is to be installed to a fire hydrant adjacent to the access road entry gates, but outside the substation enclosure, to allow the fire brigade to connect its equipment prior to them being PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 12 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 given access to the substation. Design of this service is to be as per the requirements of AS 2419.1. If an over ground stand pipe hydrant is used, care shall be taken to not allow it to be used as a fence climbing device, typically they shall be located a minimum of 5 metres from the security fence. Requirements for on-site water storage and supply Where mains water or another hydrant supply is not available or suitable, a water tank and pressure pump shall be provided. The water tank shall be 45,000 litres capacity. The substation services shall only be allowed to draw off the upper 22,500 litres via a pump supply. The lower 22,500 litres shall be plumbed so that the brigade may pump it out of the tank via a hydrant at the gate. A hydraulics layout drawing shall be produced to provide the location and reference level information for the installation and construction of all water supply equipment. 5.3.12 Deluge safety showers A minimum of one deluge shower is to be installed per substation. It shall be installed on an external building wall at or close to the HV switchgear exit, battery room/s and the switchyard area. Additional showers are to be placed to suit requirements at each installation. The following equipment is requirement as a minimum: Item 1: Combined deluge shower/eyewash system (Enware EC270)*# or equivalent; Item 2: Gate valve (Bronze 1’ BSP – British standard pipe); The deluge shower head is to be mounted 600 mm from the wall with the lower face of the shower rose 2100 mm above blue metal level. A 600 mm square, 50 mm thick concrete slab is to be placed under the shower with 25 mm fall away from the building. Any outdoor showers with exposed pipe work shall be insulated from the heating effect of the sun or from freezing. Otherwise in the event of an incident where the shower is operated it could be possible that the water in the pipes is hot or cannot operate due to being frozen. The water supply line to the deluge showers from the meter shall be 32 mm PVC. The water supply shall have a minimum pressure of 210kPA for 15 minutes, with a flow rate of 75 litres per minute. At sites without mains water supply, the shower water supply shall be supplied via a 240V AC pressure pump with water drawn from the rain water tank. In the event of a loss of 240V supply, the pump is connected to a pressurised storage tank with a volume of 70 litres, to ensure the shower will operate. 5.3.13 Earthing design The substation earth grid design shall be produced utilising the information supplied/approved by the company’s earthing manager. The earth grid layout drawing shall provide all the information required to install the earth grid equipment and make all the necessary connections. The drawing shall also include a material schedule listing the required types, sizes and numbers of conductors, earth stakes, inspection pits, connectors, lugs and fittings. The substation design group has developed a template earth grid layout drawing and shall be replicated as required. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 13 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 5.3.14 Conduits, trenches and pits For uniformity of design and to minimise stock levels, all conduits are to be selected from the table below. If the application is not listed in the table below, the most appropriate conduit size from the table shall be used. All conduits are to be heavy duty in accordance with AS2053.2:2001. Application No of Conduits Conduit Size (N.B.) Min Bend Radius 11/22kV feeder circuit 1 per feeder 150mm 2.5m Current transformer (CT) marshalling cubicle 1 125mm 600mm Dead tank CB 2 80mm 600mm Disconnector 1 50mm 600mm Light pole 1 50mm 600mm Live tank CB 1 125mm 600mm Tx control cubicle 2 125mm 600mm Tx 11/22kV cables (up to 630mm2 XLPE/PVC) 1 per cable 125mm 1200mm Aux Tx, FI Plant, cap bank 11/22kV (up to 240mm2 3 Core, Al XLPE/PVC) 1 per cable 125mm 1200mm Aux Tx 240/415V(up to 185mm2 3 core, Al XLPE/PVC) 1 per cable 125mm 600mm Voltage transformer (VT) marshalling cubicle 1 80mm 600mm Communications (white) 1 50mm 600mm Control and protection cables within the switchyard area shall generally be installed in pre-cast cable trench and conduits. The main run across the yard shall be cable trench and conduits shall be used to run from the cable trench to the equipment. 11/22kV transformer cables generally shall be installed between the transformer and switchboard, in separate pre cast cable trenches. 11/22kV cables for capacitor banks, aux transformers, distribution feeders, and frequency injection plants shall be installed in conduits. Cable trenches and pits shall be pre-cast from polymer concrete or plastic and shall be of box section with removable covers. The covers shall be rated to carry 200kg point load without extra support braces in non-traffic areas. The pit and trench covers shall be made from Fibre Reinforced Polymer (FRP) solid top moulded grating. Concrete, fibrous cement sheeting or polymer concrete covers shall not be used. For traffic areas, trench sections and covers shall be suitably designed for a single 15 tonne GVM rigid vehicle. The trench may be constructed on-site from concrete and covers may be constructed from concrete or galvanised steel. The area designed for vehicle access shall be coloured or painted yellow and shall be shown on the trench layout drawings. Cable pits and trenches shall be placed so that the top of the cover is 50mm above the finished surface level. Where practical, conduits for LV and control cables shall be installed with a vertical separation of 100mm and horizontal separation of 200mm from the earth grid conductors. In general when precast cable trenches are utilised, conduits installed from the trench to the yard equipment shall be installed 100mm above the earth grid conductors, level with the base of the cable trench. Conduits for HV cables shall be installed at a minimum depth of 700mm to finished surface level. Conduits for LV and control cables shall be installed with a vertical separation of 300mm and horizontal separation of 400mm from HV cables. The conduits for LV and control cables should not run in parallel with HV cables where practical, it is preferred to maintain adequate separation PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 14 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 and for the conduits to cross HV cables at 90° to minimise the influence of induction on control cabling. Pits, cable trenches and conduits shall be excavated such that there is a fall from end to end so that rainwater can drain out in drainage lines. Conduits and pits shall be bedded on a layer of clean sand 50mm thick. Conduit trenches shall be back filled with clean sand to provide a minimum cover of 50mm above the top of the conduit; the trenches are then backfilled with the excavated material as trench backfill. The transformer cable design must ensure that the transformer cables maintain separation from cables of other transformers. If the cables need to cross or are placed adjacent to each other permanent fire proof barriers must be designed and installed. Where conduits terminate at a trench, pit, and masonry building or basement walls, bell mouths are to be fitted on the inside of the wall. The substation design group has developed a suite of template conduit, pit and trench drawings and shall be replicated as required. The cable trench, conduit and pit layout drawing shall be produced to indicate the types, sizes and locations of all conduits, pits and drainage lines. Trench sections drawings shall be shown detailing the installation depths, bedding materials and compaction. The drawing shall also include a material schedule listing the required types, sizes and numbers of conduits, pits, bends and bell mouths. 5.3.15 Landscape design The company has a comprehensive environmental policy that calls for all new installations to have a minimal visual impact. As such, all new substations are to be landscaped to improve their aesthetic appearance for the public. A landscaping drawing and specification is required to be produced. Where water sprinklers are required the design and installation is to be carried out by a single contractor. Care is to be exercised when designing the water sprinkler layout so as not to interfere with the earth grid, conduits, drains and cabling. Wherever possible, trees and shrubs used for landscaping purpose shall be Australian native plants, they shall also be suitable for both the climate and soil conditions prevalent in that area. The requirements of the local councils also need to be considered. Shrubs and trees to be planted beneath overhead feeders leading into substations are to be selected from tree management information provided on the company’s website. Special attention shall be made to high voltage underground cable duct routes. No trees or shrubs are to be planted within a 2 metre strip centred on underground service lines. Only ground covers are to be used in these areas. 5.3.16 Structural Steelwork Design The substation design group has developed a suite of template steelwork design drawings and shall be replicated as required. If a suitable steelwork design is not provided in the suite of drawings, a design shall be produced and certified by a qualified structural engineer. It is preferable that consistent types of materials, rag bolt assemblies, methods of manufacture and assembly are used. All steelwork is to be hot dipped galvanised. 5.4 Building design 5.4.1 General The types of substation buildings required by the company vary on a project specific basis. The project definition shall outline the building type and key requirements. The substation design group has developed four main substation building types: type 1 two story masonry switchboard and control building with cable basement; PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 15 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES type 2 type 3 type 4 Amendment No: 8 single story masonry switchboard and control building with cable pit; prefabricated switchboard building, mounted on piers with cable basement; and prefabricated control building placed at ground level with cable pit. The building design package shall include design drawings specific for the type of building nominated for the project, they shall include: floor plans; elevations; foundations and piers; structural layouts; concrete slab details; roof plans and sections; wall plans and sections; electrical & plumbing layouts; steps & landings; and door, fittings, window and finishes schedules. 5.4.2 Performance criteria It is the company’s requirement that the designed building: be able to provide an uninterrupted electricity supply during extreme weather events; is able to retain good post-disaster functions; and have a service life of 40 years and is to be constructed from materials which will require minimal future maintenance. The structural design must comply with the following minimum general design performance criteria: All structural design and documentation shall be the responsibility of an engineer qualified for corporate membership of the Institution of Engineers Australia and National Professional Engineers Register, registered with qualifications to undertake the work required Appropriate site investigations and reports are required to be obtained for the proposed building in accordance with AS 1726. An appropriately qualified geotechnical engineer shall carry out the site classification. Foundation design recommendations for the site shall relate to the latest edition of AS 2870 The structural design shall be undertaken in accordance with all relevant Australian Standards, the Building Code of Australia (BCA), building construction regulations, local council requirements, and Essential Energy’s project definition. The design shall not only have sufficient strength to resist the minimum loads specified by the above listed standards or regulatory authorities, but shall also be serviceable with respect to short term and long term deflections, vibrations and durability in accordance with industry best practice The building shall be able to support the loads of all equipment as well as the dead, live, wind, snow and earthquake loads defined in the AS/NZS 1170 series of standards. Special attention shall be given to the design details, construction methods, and workmanship to ensure weather tightness. As a minimum substation buildings shall comply with the provisions of the BCA, where relevant. The BCA does not have a specific class for substation buildings but they are generally considered as Class 8 buildings. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 16 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 Design equipment loadings The building shall be designed to accommodate all equipment static and dynamic loadings including point loads, vertical single loads, horizontal single loads in –X and –Y directions, vertical area loads and transport loads. Floor area over which the equipment must be moved to reach its final installed position must be designed to withstand forces applied by the equipment. For floor areas outside of the switchgear and transport area, a live load of p = 10kN/m2 in worst position must be taken into account. Serviceability requirements The building’s structure shall incorporate adequate movement joints to accommodate volumetric changes in the structural elements due to temperature and moisture variations, load deformations and foundation movement. The wall strength shall be sufficient withstand all static and dynamic loads due to normal operation of the installation and abnormal conditions associated with equipment failure. The building design shall address the serviceability and durability requirements of all relevant Australian Standards and shall ensure that deflections are within the limits of these relevant Australian Standards. The structural components shall be designed and constructed so that any deflections under service loads are within the limits for structural integrity and/or visual appearance, avoid excessive floor slopes, permit proper installation and operation of equipment within the equipment’s operating tolerances, prevent cracking of floors, walls and ceilings, are not noticeable to traffic or the building occupants, and avoid ponding of water. All vibration producing equipment shall be isolated from the structure to minimise any transfer of vibration where possible. Notwithstanding this, the building shall be designed to withstand vibration loads of all vibration producing equipment like switchgear for example. The structure supporting concrete or masonry walls is to be designed to ensure that any movement is within the requirements of AS 3700. The design shall ensure elements are provided which can direct and accommodate building movement without detriment to the wall’s appearance. The design shall incorporate structural tolerances. Construction tolerances for structural components are to be as nominated in relevant design codes and as required for the finishes applied over those structural components. All structural steelwork design and detailing shall conform to the latest or equivalent version of AS 4100. The surface preparation and priming of the structural steel shall be appropriate to the exposure of the steelwork. As a minimum all steelwork shall be hot dip galvanised after fabrication to satisfy the requirements of AS/NZS 4680. All roof designs shall ensure that the roof slope and deflection of roof members are within acceptable limits to avoid ponding and leakage to the roof. Adequate anchorage shall be provided against uplift forces and if necessary, the anchorage taken down to the floor slab or footings. All concrete elements are to be designed to AS 3600 and AS 3610 with special consideration to the following: minimum ratios of reinforcement in slabs and walls for shrinkage and temperature cracking control; and durability of all externally exposed reinforced concrete to achieve the specified design life of 40 years. 5.4.3 Fire risk & fire resistance level The fire resistance level requirements for the substation buildings shall generally be determined in the project definition. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 17 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 The fire risk for the company’s substation buildings is determined by assessing the risk of fire from external and internal fire sources. External fire sources can be controlled by ensuring the substation buildings have adequate separation or clearance zones from external fire sources such as the transformers and adjacent properties. Internal fire sources are managed by ensuring the substation buildings are constructed from non-combustible materials and modern indoor power equipment normally does not contain transformer oil. If a building is assessed to have a genuine fire risk, a fire resistance level shall be nominated in the project definition. The building shall then be designed and constructed to the relevant conditions as outlined in the Australian Standards and the BCA. The fire resistance design shall include floors, frames, walls, doors, door frames, shutters, roofs and cable penetrations. 5.4.4 Type 1 - two story masonry switchboard and control building with cable basement The type 1 substation switchboard and control building is used to house all control and protection equipment, batteries, employees amenities and the indoor type high voltage switchgear. The substation design group has developed a suite of template building layouts, floor plans and construction methods which are to be used as the basis of the final building design. The design of the building is to be pre-cast concrete tilt panel wall construction with steel roof frame and sheeting. All internal walls are to be concrete tilt panel construction. The building has been designed to be extended in variable sections up to 4 metres in width as determined by the specific requirements of each project. In accordance with the Code of Practice for Electricity Transmission and Distribution Asset Management, no provision has to be made for access to the substation buildings by persons not capable of safely performing the work to be undertaken and capable of rescuing and releasing another person. Segregation of equipment In general the building shall be divided into purpose built rooms and areas with specific design features. The building may include: 11kV/22kV switchboard room; 11kV/22kV frequency injection plant room; control room; amenities; battery room/s; cable basements; and first floor landings. 11kV/22kV switchboard room The 11kV/22kV switchboard room is designed specifically to only house the high voltage switchboard. The dimensions of the switchboard room shall be determined by the specific requirements of the switchboard and space for additional future panels as determined in the project definition. Generally the rear of the switchboard is to be located a minimum of 700mm from the external wall and a minimum of 2500mm is required in front of the switchboard. Switchboard room floors are to have a tolerance of +/-1mm in any 1 metre circular area and a tolerance of +/-3 mm over the entire switchboard length. This tolerance is required to meet switchgear manufacturer’s requirements. Prior to finalization of design, switchgear supplier requirements shall be confirmed. 11kV/22kV switchboard room floors shall be constructed using a high strength 40MPa concrete so as to provide the necessary durability for the switchgear. All areas containing 11kV/22kV switchboards are to be provided with pressure relief panels fitted to external walls so arranged that in the event of an internal pressure increase in the order of 0.4 kilopascals, they operate to relieve the pressure from the enclosure. The area of pressure relief PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 18 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 panels is in the ratio of 1 square metre of relief panel to each 60 cubic metres of room volume. In the event of the pressure relief devices operating during a storm, they shall be constructed so as to provide effective weatherproofing. The pressure relief devices shall be vermin and insect proof. The switchboard room shall have a minimum of one (1) external double equipment access door and one (1) external personal entry door and one (1) internal personal entry door to the control room. The two (2) access/exit doors must be spaced as far apart as practicable in accordance with relevant standards. The double equipment doors must provide sufficient clearance for installation and removal of the switchboard panels. Personal entry doors must have minimum dimensions of 2000 x 900mm. The company’s standard locks must be fitted to each external door. The company will provide final cylinders to all deadlocks. Internal doors shall be fitted with passage latches. A door-retaining device will be fitted to all doors to be held in the open position when required. The fixed door section will be fitted with a shooting bolt operated from a position two metres above floor level to firmly lock the fixed section of the double equipment doors, without the need to ascend steps. Dust sealing will be included on each door. Each external door must open outwards and the internal door must open in to the control room. Switchboard rooms will either be designed so that the room ambient temperature does not exceed 25°C or will be air conditioned using a reverse cycle split system. Type 1 buildings have floor penetrations designed for the installation of both high voltage cables and low voltage control cables. 11kV/22kV Frequency injection (FI) plant room The 11kV/22kV FI plant room is designed specifically to only house the FI plant. The dimensions of the FI plant room shall be determined by the specific requirements of the equipment and space for addition future panels as determined in the project definition. Pressure relief venting shall be provided as per the requirements of the switchboard room. The FI plant room shall have a minimum of one (1) external double equipment access door. The double equipment doors must provide sufficient clearance for installation and removal of the frequency injection plant. The company’s standard locks must be fitted to each door. The company will provide final cylinders to all deadlocks. A door-retaining device will be fitted to all doors to be held in the open position when required. The fixed door section will be fitted with a shooting bolt operated from a position two metres above floor level to firmly lock the fixed section of the double equipment doors, without the need to ascend steps. Dust sealing will be included on each door. Each external door must open outwards. There shall be a 300 x 300 Lexan 3mm clear perspex viewing window fitted to both faces of one of the doors. Control room The control room is designed to house the control and protection panels, SCADA, communication equipment, battery chargers and to provide a basic work area with desk, phone etc. Control rooms will either be designed so that the room ambient temperature does not exceed 25°C or will be air conditioned using a reverse cycle split system. The control room shall have a minimum of one (1) external double equipment access door and one (1) external personal entry door. The two (2) access/exit doors must be spaced as far apart as PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 19 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 practicable in accordance with relevant standards. The double equipment doors must provide sufficient clearance for installation and removal of the control panels. Minimum dimensions shall be 2400 x 1600mm. Personal entry doors must have minimum dimensions of 2000 x 900mm. The company’s standard locks must be fitted to each external door. The company will provide final cylinders to all deadlocks. Internal doors shall be fitted with passage latches. A door-retaining device will be fitted to all doors to be held in the open position when required. The fixed door section will be fitted with a shooting bolt operated from a position two metres above floor level to firmly lock the fixed section of the Double Equipment doors, without the need to ascend steps. Dust sealing will be included on each door. Each external door must open outwards. Type 1 buildings shall have floor penetrations to the basement to allow for the installation of LV control and communication cables. Amenities A toilet is to be provided for employees use. Hand washing facilities with hot and cold water is also required. An instantaneous electric over sink hot water dispenser shall be installed. Toilet rooms are to have floor tiles, floor waste, ventilation and have vermin and insect proofing installed. Battery rooms The battery room is designed specifically to only house the substation batteries. The project definition shall state the type and size of the batteries to be installed and if one or two battery rooms are required. Battery rooms shall be fitted with ventilation to the outside of the building. The rooms shall be limited to 2% concentration of hydrogen at maximum battery charging current. The preferred method natural ventilation using low wall/door and roof vents. The battery room shall have a minimum of one (1) external equipment access door and one (1) internal personal entry door opening in to the control room. The access/exit doors must be spaced as far apart as practicable. The external equipment door must open outwards and must provide sufficient clearance for installation and removal of the batteries. The company’s standard locks must be fitted to the external door. The company will provide final cylinders to all deadlocks. Equipment access door must have the minimum dimensions of 2000 x 1200mm. Personal entry doors must have minimum dimensions of 2000 x 900mm. A door-retaining device will be fitted to all doors to be held in the open position when required. Dust sealing will be included on each door. Battery room lighting including emergency exit lighting shall be a bulkhead or fully enclosed style suitable for the area. The deluge safety shower/eye wash shall be located in close proximity to the battery room, if this is not practical, a dedicated wash facility shall be provided adjacent to the battery room exit. Cable Basement The purpose of the cable basement is to provide a suitable area to install, fix and support low voltage control, communication and high voltage cables. Generally the high voltage cable will be fixed in position on the floor of the basement and the low voltage cables shall be located on cable tray fixed to the ceiling. The cable basement shall be designed with a minimum clearance height of 2400mm from basement floor to ceiling. The basement floor level is to be approximately 1200mm below the switchyard’s finished surface level. A minimum of two access doors at opposite ends shall be provided to the basement. If required, one double door for equipment access shall be provided with access via a ramp suitable for vehicle access. The basement shall have a minimum of one (1) external double equipment access door and one (1) personal entry door. The two access/exit doors must be spaced as far apart as PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 20 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 practicable. The double equipment doors must have minimum dimensions of 2200 x 1800mm and may have vehicle access via a concrete ramp if required. Personal entry doors must have minimum dimensions of 2000 x 900mm. The company’s standard locks must be fitted to each door. The company will provide final cylinders to all deadlocks. All doors shall open outwards. Openings shall be provided on the basement wall, above ground level to provide cable pulling access and to provide basement ventilation. The opening shall be fitted with removable louvers or grates and shall be insect and vermin proof. They shall be located on opposite walls to all conduit entry points. A perimeter drain and sump shall be designed to continuously drain any water from the basement to the substation stormwater drainage system. First floor landings First floor landings are to be designed to ensure that emergency egress is not impeded by opening any or all of the first floor external doors or deluge showers. Safety railings are required on basement steps, ramps, balconies or loading docks where required under the building code. In all cases ensure water is not trapped where railings and their fittings meet or penetrate the concrete. Railings across loading docks are to be removable. Loading dock heights are generally to be 1300 mm above road level to suit the company’s vehicle tray heights. Entry areas shall be sloped out of the building to avoid water ingress. The area shall be finished to allow a smooth transition into the building with a trolley or pallet jack. All loading docks are to be provided with a “drip nose” to prevent staining of brickwork . 5.4.5 Type 2 - single story masonry switchboard and control building with cable pit The type 2 substation switchboard and control building is used to house all control and protection equipment and batteries and the indoor type high voltage switchgear. The substation design group has developed a suite of template building layouts, floor plans and construction methods which are to be used as the basis of the final building design. The design of the building is to be pre-cast concrete tilt panel construction with steel roof frame and sheeting. . All internal walls are to be concrete tilt panel construction. The building is single story and includes a High Voltage cable pit and Low voltage cable trench. The building has been designed to be extended in sections of 4 metres as determined by the specific requirements of each project. Segregation of Equipment In general the building shall be divided into purpose built rooms and areas with specific design features. The building may include: 11kV/22kV switchboard room; 11kV/22kV FI plant room; control room; amenities; battery rooms; and high voltage cable pit. The specific design criteria for the switchboard, FI, battery rooms and amenities are the same as detailed for type 1 buildings. Control room The control room is designed to house the control and protection panels, SCADA, communication equipment, battery chargers and to provide a basic work area with desk, phone etc. Control rooms will either be designed so that the room ambient temperature does not exceed 25°C or will be air conditioned using a reverse cycle split system. The control room shall have a minimum of one (1) external double equipment access door and one (1) external personal entry door. The two (2) access/exit doors must be spaced as far apart as PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 21 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 practicable in accordance with relevant standards. The double equipment doors must provide sufficient clearance for installation and removal of the control panels. Minimum dimensions shall be 2400 x 1600mm. Personal entry doors must have minimum dimensions of 2000 x 900mm. The company’s standard locks must be fitted to each external door. The company will provide final cylinders to all deadlocks. Internal dors shall be fitted with passage latches. A door-retaining device will be fitted to all doors to be held in the open position when required. The fixed door section will be fitted with a shooting bolt operated from a position two metres above floor level to firmly lock the fixed section of the double equipment doors, without the need to ascend steps. Dust sealing will be included on each door. Each external door must open outwards. Type 2 buildings shall have a low voltage cable trench. The purpose of the low cable trench is to provide a suitable area to install, fix and distribute low voltage control cables between equipment in the building such as the batteries, battery chargers, control & protection panels and the switchyard equipment. The cable trenches are to be designed into the floor under the control panels to cable pits. Under floor conduits from other sections of the building and external conduits from the switchyard shall be terminated in the cable pits. They are to be as wide as the base access of the control panels that rest on them. The trenches shall also be deep enough to hold at least twice the max quantity of cables expected to be installed. The cable pit shall be continuously drained to the substation stormwater drainage system. High voltage cable pit Type 2 building shall have a cable pit located behind the switchboard. The purpose of the cable pit is to provide a suitable area to install, fix and support high voltage cables to the indoor switchboard. The cable pit shall be designed to suit the minimum bending radius of the cables and cable pull in anchors shall be designed and installed to provide ease of cable installation. A minimum of two access steps at opposite ends shall be provided to the pit. Removable pit covers shall be designed for pedestrian access to the rear of the switchgear and suitable ventilation shall be provided. The cable pit shall be continuously drained to the substation stormwater drainage system. 5.4.6 Type 3 - prefabricated switchboard building, mounted on piers with cable basement The type 3 substation prefabricated switchboard building is designed to house the 11kV or 22kV switchboard only. Switchboard building The design of the building is a transportable prefabricated steel framed construction with steel colorbond or equivalent or equivalent cladding and linings to suit the external environment and the internal function. The building shall be provided with overpressure shutters. The building shall be mounted on piers and generally will achieve a floor height of 1200mm above ground level. Generally the switchboard and prefabricated building shall be purchased by the company on a major equipment supply contract. The manufacturer shall provide the final building and pier layout drawings and the company is required to provide the foundation/cable pit design drawings. The substation design team has developed template foundation/cable pit drawings which are to be used as the basis of the final design. The dimensions of the switchboard building shall be determined by the specific requirements of the switchboard and space for addition future panels as determined in the project definition. Generally the rear of the switchboard is to be located a minimum of 700mm from the external wall and a minimum of 2000mm is required in front of the switchboard with the circuit breaker trucks placed in front of the switchboard. Switchboard room floors are to have a tolerance of +/-1mm in any 1 metre circular area and a tolerance of +/-3 mm over the entire switchboard length. This tolerance is PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 22 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 required to meet switchgear manufacturer’s requirements. Prior to finalization of design, switchgear supplier requirements shall be confirmed. All areas containing 11kV/22kV switchboards are to be provided with pressure relief panels fitted to external walls so arranged that in the event of an internal pressure increase in the order of 0.4 kilopascals, they operate to relieve the pressure from the enclosure. The area of pressure relief panels is in the ratio of 1 square metre of relief panel to each 60 cubic metres of room volume. In the event of the pressure relief devices operating during a storm, they shall be constructed so as to provide effective weatherproofing. The pressure relief devices shall be vermin and insect proof. The switchboard room shall have a minimum of one (1) external double equipment access door and one (1) external personal entry door. The two access/exit doors must be spaced as far apart as practicable. The double equipment doors must provide sufficient clearance for installation and removal of the switchboard panels. Personal entry doors must have minimum dimensions of 2000 x 900mm. The company’s standard locks must be fitted to each door. The company will provide final cylinders to all deadlocks. A door-retaining device will be fitted to all doors to be held in the open position when required. The fixed door section will be fitted with a shooting bolt operated from a position two metres above floor level to firmly lock the fixed section of the double equipment doors, without the need to ascend steps. Dust sealing will be included on each door. Each external door must open outwards and the internal door must open in to the control room. Switchboard building shall be air conditioned using a reverse cycle split system have and be designed so that the room ambient temperature does not exceed 25°C. The building has floor penetrations designed for the installation of both high voltage cables and low voltage control cables. Cable basement The purpose of the cable basement is to provide a suitable area to install, fix and support low voltage control, communication and high voltage cables. Generally the high voltage cable will be fixed in position on a cable support frame and the low voltage cables shall be located on cable tray. The cable basement shall be designed with a minimum clearance height of 2400mm from basement floor to the floor structure of the building floor. A minimum of two access steps at opposite ends shall be provided to the basement. A perimeter drain and sump shall be designed to continuously drain any water from the basement to the substation stormwater drainage system. Steps and landings Steps and landings are to be designed to ensure that emergency egress is not impeded by opening any or all of the external doors. Safety railings are required on basement steps, ramps, balconies or loading docks where required under the building code. In all cases ensure water is not trapped where railings and their fittings meet or penetrate the concrete. Railings across loading docks are to be removable 5.4.7 Type 4 - prefabricated control building placed at ground level with cable pit The type 4 substation prefabricated control building is used to house all control and protection equipment, batteries and employees amenities. The design of the building is to be a transportable prefabricated steel framed construction with steel colorbond or equivalent or equivalent cladding and linings to suit the external environment and the internal function of each room, The substation design team has developed a suite of template building layouts and floor plans which are to be used the basis of the final building design. Generally the control building final design drawings shall be provided by the building manufacturer and the company is required to provide the foundation/cable pit design drawings. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 23 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 Segregation of equipment The type 4 - prefabricated control building shall be divided into purpose built rooms and areas with specific design features. The control building may include: control room; amenities; battery rooms; and cable pit. Control room The control room is designed to house the control and protection panels, SCADA, communication equipment, battery chargers and to provide a basic work area with desk, phone etc. Control rooms will either be designed so that the room ambient temperature does not exceed 25°C or will be air conditioned using a reverse cycle split system. The control room shall have a minimum of one (1) external double equipment access door and one (1) external personal entry door. The two (2) access/exit doors must be spaced as far apart as practicable in accordance with relevant standards. The double equipment doors must provide sufficient clearance for installation and removal of the control panels. Minimum dimensions shall be 2000 x 1600mm. Personal entry doors must have minimum dimensions of 2000 x 900mm. The company’s standard locks must be fitted to each external door. The company will provide final cylinders to all deadlocks. Internal dors shall be fitted with passage latches. A door-retaining device will be fitted to all doors to be held in the open position when required. The fixed door section will be fitted with a shooting bolt operated from a position two metres above floor level to firmly lock the fixed section of the double equipment doors, without the need to ascend steps. Dust sealing will be included on each door. Each external door must open outwards. Amenities A toilet is to be provided for employees use. Hand washing facilities with hot and cold water is also required. An instantaneous electric over sink hot water dispenser shall be installed. Toilet rooms are to have floor waste, ventilation and have vermin and insect proofing installed. Battery rooms The battery room is designed specifically to only house the batteries. The project definition shall state the type and size of the batteries to be installed and if one or two battery rooms are required. Battery rooms shall be fitted with ventilation to the outside of the building. The rooms shall be limited to 2% concentration of hydrogen at maximum battery charging current. The preferred method natural ventilation using low wall and roof vents. The battery room shall have a minimum of one (1) external equipment access door and one (1) internal personal entry door opening in to the control room. The access/exit doors must be spaced as far apart as practicable. The external equipment door must open outwards and must provide sufficient clearance for installation and removal of the batteries. The company’s standard locks must be fitted to the external door. The company will provide final cylinders to all deadlocks. Equipment access door must have the minimum dimensions of 2000 x 1200mm. Personal entry doors must have minimum dimensions of 2000 x 900mm. A door-retaining device will be fitted to all doors to be held in the open position when required. Dust sealing will be included on each door. Battery room lighting including emergency exit lighting shall be a bulkhead or fully enclosed style suitable for the area. Low voltage cable pit The purpose of the low cable pit is to provide a suitable area to install, fix and distribute low voltage control cables between equipment in the building such as the batteries, battery chargers, control & protection panels and the switchyard equipment. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 24 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 A low voltage cable pit design is to be incorporated into the building foundation design. It is to be located behind and under the building, below the control panels. Internal and external conduits from the switchyard shall be terminated in the cable pits. They are to be as wide as the base access of the control panels that rest on them. The trenches shall also be deep enough to hold at least twice the max quantity of cables expected to be installed. The cable pit shall be continuously drained to the substation stormwater drainage system. 5.4.8 Masonry buildings design criteria (Type 1 & 2) Floor construction All concrete floors are to be steel trowel finished to class 2 as per AS3610 and sealed with a polyurethane sealant. The switchboard room floor tolerances are critical and shall be as specified in section 4.4.6.1. A set down in the floor slab is required to house the height adjustable unistrut that the switchboard sits on. This unistrut is installed after the slab is poured. The set down concrete is poured using the unistrut to screen to. This is to be noted on the detailed construction drawings. Entry areas shall be sloped out of the building to avoid water ingress. The area shall be finished to allow a smooth transition into the building with a trolley or pallet jack. A minimum of two earth ferrules connected to the steel reinforcing on all concrete floors shall be installed. They are typically located at opposite corners. Wall construction All walls are to be concrete tilt-up panels as per AS3850-2003, with finish Class 2 as per AS 3610. Design and construction of the tilt-up walls shall be as per AS3850-2003. Internal walls shall be painted off white interior flat acrylic paint. External walls shall be painted with exterior long lasting and durable mineral silicate masonry paint. Cast in ferrules are to be provided for fixing points or attachment points, where required. A minimum of one cast in earth ferrule connected to the steel reinforcing on all concrete tilt panel sections and be installed. Roof and guttering construction The roof must be gable construction and must have a minimum slope of 10 degrees. Colorbond or equivalent guttering and downpipes must be included. The roof must be insulated with R1.5 fibreglass insulation material. The roof must be clad with BlueScope Colorbond or equivalent custom orb or equivalent fixed to purlins using 0.48 BMT roofing screw. The roof must be finished with colorbond or equivalent barge capping and guttering. The roof and gutter colour will be selected from available standard BlueScope Colorbond or equivalent sheeting. 5.4.9 Prefabricated buildings design criteria (Type 3 & 4) Floor joists and floor construction Floor joist construction must be designed to allow transportation and lifting of the building with the switchboard or control & protection panels installed. The floor structure must consist of compressed cement fibre sheeting covered with hard wearing commercial grade vinyl. Areas in front of 11/22kV switchboards may require additional floor protection such as metal sheeting such as stainless steel, to allow for easy removal and manipulation of the circuit breaker trucks. An unrestricted and sealable cable entry opening must be available for the installation of high voltage and low voltage cables. Wall and ceiling construction External wall cladding must be BlueScope Colorbond or equivalent sheeting. The colour will be selected from available standard BlueScope Colorbond or equivalent. Internal wall and ceiling must be lined with BlueScope Panel rib Colorbond or equivalent 0.35 BMT cladding. The ceiling colour PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 25 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 shall be ‘Off White’. Fixing shall be flat head self-tapping screws. Wall and ceiling insulation must be provided with 75mm thick fibreglass batts and provided with a moisture barrier such as sarking. Roof and guttering construction The roof must be gable construction and must have a minimum slope of 5 degrees. Colorbond or equivalent guttering and downpipes must be included. The roof must be insulated with R1.5 fibreglass or equivalent insulation material. The roof must be clad with BlueScope Colorbond or equivalent Trimdeck fixed to purlins using 0.48 BMT roofing screw. The roof must be finished with colorbond or equivalent barge capping and guttering. The roof and gutter colour will be selected from available standard BlueScope Colorbond or equivalent sheeting. 5.4.10 Building services Electrical Wiring must be terminated at a 415V AC distribution board supplied and fitted on an internal wall. The 415V AC distribution board must be supplied complete with main switch, circuit breakers & residual current device’s (RCD). Emergency exit lights must be installed above each external door. Emergency exit light fittings above doors must be twin 10W fluorescent type. Interior light fittings must be twin 36W fluorescent type, surface mounted to the ceiling. Interior light fittings must provide illuminance of 300 Lux at floor level. Interior emergency light fittings must be twin 36W fluorescent type, surface mounted to the ceiling with one tube maintained on battery pack. A minimum of 2 emergency light fittings must be provided. All interior light fittings must be provided with polycarbonate diffusers. Exterior light fittings must be twin 18W fluorescent type, pole mounted to the outside wall. Auto/manual switch and photo-electric sensor must be installed. A minimum of four (4) general purpose outlet’s (GPO’s) must be installed in Control rooms and a minimum of two (2) in each switchboard room and must be twin 240V, 10A with three flat pins, single pole switch and 30mA RCD protection. Each Control & Switchboard room shall also be fitted with One 3 phase GPO must be 415V, 16A with five round pins, heavy duty switch and 30mA RCD protection. Wiring to lights, switches and power outlets must be concealed within wall spaces when possible. The electrical layout drawing shall be produced to provide the location and reference information for the installation and wiring of the light, power, air conditioning, smoke and thermal detectors, hot water service, pumps, fans and any other permanently wired electrical equipment. Fire management A minimum of 2 smoke detectors, with clean contacts for remote indication in addition to shutting off any air conditioning, must be provided in each control and switchboard room. Each battery room shall have a minimum of one thermal sensor. All other rooms shall have a minimum of one smoke sensor. There shall be a minimum of one Brooks sounder base installed in each room for the purpose of alerting on site personnel in the event of any sensor being activated. The sensors will be connected to a Brooks Fire Tracker 1 FT1-SB panel. The fire panel system shall provide clean contacts for remote indication to the substation SCADA system and contacts to shut off any air conditioning. Fire extinguishers of type CO2 are to be installed in the substations to Australian Standards. The fire extinguishers are to be mounted adjacent to entry and exit doors in the control building. All cable penetrations of walls or floors shall be sealed to prevent the spread of fire, smoke and corrosive fumes. Plumbing The plumbing layout drawing shall be produced to provide the location and reference information for the installation of all water, drainage and sewerage pipes and fittings. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 26 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 Finishes A finishes schedule shall be produced to provide detail for all materials, finishes and fittings required to construct the building. Information provided shall include: wall, ceiling and floor finishes, painting, waterproofing, sealing and tiling; roofing, guttering, downpipes, barge capping; doors, door frames and door furniture; windows, screens, louvers, vents; air conditioners – (industrial/commercial quality); switchboards, GPOs, lights, exit lights and light switches; fans, water pumps and other electrical equipment; toilets, hand basins; and fire extinguishers. 5.5 Primary system design 5.5.1 General The primary system design package shall be designed in accordance with the relevant Australian standards and reference shall be made to the conditions and or control measures detailed in the environmental assessment. The primary system design shall provide all the required information for the installation of the primary system equipment. This shall include plant and equipment layout, safety clearances, high voltage connections & fittings, busbar manufacture, earthing connections and safety screens or barriers. Primary system equipment shall include but not be limited to, the following equipment: power transformer; auxiliary transformer; circuit breakers and switchboards; capacitor bank; frequency injection plant; disconnector; earth switch; fuse; current transformer; voltage transformer; rigid and flexible overhead busbar; underground cables; lightning masts; insulator; surge arrestors; yard lighting; and security fence. The size, type, quantity of primary system equipment will be identified in the project definition. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 27 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES 5.5.2 Amendment No: 8 Primary system design drawings The primary system design package shall contain, but is not limited to the following drawings: general arrangement plan view of substation; general arrangement elevation views within the substation; substation site plan; substation lightning protection layout; high voltage busbar fabrication drawing; high voltage power cable schedule; earthing connection drawings for yard equipment; and primary system equipment schedules. The substation design group has developed a suite of template primary system design drawings and shall be replicated as required. All the template designs are to be assessed as suitable for the specific situation. Information and recommendations from the project definition shall be used to review and complete the design. General arrangement drawing – plan view The purpose of the general arrangement drawing is to detail an overall plan view of the substation. All major equipment items, including but not limited to, buildings, switchgear and capacitor banks are to be shown. A table is to be included documenting all major equipment items quantities, details and any other relevant details required for procurement. The GA plan view must also include section markers for elevation views of the transverse bus, transformer and feeder bay. Only one section marker is required for each identical bay. All equipment is to be dimensioned from the set out lines. General arrangement drawing – elevations The elevation views show the layout of transverse busbars and each bay configuration and are to itemise all equipment to allow for the production of the bill of materials. Details of each Item, including total quantities, are to be included in the table listing all major equipment items. Identical bay layouts shall be shown on the same elevation. Substation site plan The purpose of the site plan drawing is to detail the location and arrangement of the substation on block of land. The benchmark location is shown and dimensions to the substation set out lines are detailed. The drawing also shows the access roads, vegetation buffer zones and HV power line locations. Lightning protection drawing The lightning protection drawing is to consist of a plan view, and a section view detailing the extent of lightning protection coverage within the substation security fence. The plan view of the lightning protection drawing is to include an elevation section marker between two adjacent lightning spikes separated by the greatest distance. The elevation section is to highlight the lightning protections lowest point of coverage is still above heights detailed in clause 3.5.5 HV busbar fabrication drawing HV busbar fabrication drawings are to include all material details, sizes, specifications and relevant information to allow for correct manufacture and assembly for all busbars. HV power cable schedule The HV cable schedule identifies each HV cable, its origin and destination, size, type and length of cable, any relevant drawing references and cable termination kit details. Each HV cable is to be identified by a unique cable number. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 28 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 Primary system equipment schedule The primary system equipment schedule is the bill of materials required for construction of the entire primary electrical system. The schedule is to include all information required to purchase equipment on the list including all quantities. 5.5.3 Clearances To ensure uniformity of design, the following standard clearances are listed below and are to be used whenever possible. Bay centres may however, be varied to suit the site when required. CLEARANCES Ground safety clearance Phase to earth (non flashover) Phase to phase Feeder bay centres Transformer bay centres (or bus section CB) Section safety clearance Busbar phase centres Feeder/ transformer busbar height Transverse bus busbar height Spacing for fire protection, transformer to transformer or transformer to building Spacing from equipment & buildings to fence (internal) Security clearance zone outside substation fence 11kV 22kV 33kV 66kV 2500 420 695 475 790 6000 10000 12000 14000 2620 2750 2860 3200 1000 1500 3000 3500 4000 5000 - - 10000 132kV 1430 1625 17000 21000 3900 2800 4000 6000 15000 Min 5000 to closest piece of equip/building Min 5000 (to closest plant/object/climbing aid) Minimum clearances in all situations shall be as per AS2067. Air insulated 11 or 22kV outdoor equipment will be fitted with 33kV insulators. This may require the use of 33kV equipment. 5.5.4 Lightning impulse withstand voltage level To ensure uniformity of design, the following standard lightning impulse withstand voltage levels are listed below. System voltage Rated voltage Lightning impulse voltage 5.5.5 11kV 12kV 95kV 22kV 24kV 150kV 33kV 36kV 200kV 66kV 72.5kV 325kV 132kV 145kV 650kV Primary system equipment Power transformers Power transformers are to be positioned such that the radiators face the access road. A barrier may be required to shield the HV from road using vehicles should statutory clearance not be available. The convention to follow when numbering transformers is, when standing on the access road facing the transformers reading left to right, the numbers are 1,2,3,4 etc. Auxiliary transformers The number and power ratings of the auxiliary transformers shall be determined in the project definition. Generally, the company’s standard padmount transformers shall be used which include a built in oil bund, 11/22kV fuses and LV fuse switches. The 11/22kV supply connections for the auxiliary transformers shall be determined in the project definition and shown on the single line diagram. Typically there are several options; they can be supplied by a discrete high voltage circuit breaker, or piggy-backed off an 11/22kV capacitor bank, PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 29 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 FI plant or distribution feeder circuit breaker. If two auxiliary transformers are required, they are to be fed from different sections of the 11/22kV busbar. Where possible, to allow for connection to oil filtration equipment, auxiliary transformers are to be located no more than 40 meters from any power transformer bund. Circuit breakers & switchboards Outdoor circuit breakers are to be positioned such that all safety clearances are to be maintained at all times. Indoor switchboards are to be positioned within the control building to allow for safe access to the switchgear during both operation and maintenance. When facing the switchboard inside the control building, shall be numbered left to right, eg Feeder 1 (Fdr), Tx1, Fdr2, Bus-Sect, Fdr3, Tx2, Fdr4 etc. Capacitor bank Capacitor banks are to be positioned within the substation with consideration of operating noise. Sound attenuating walls may be required to reduce impact to neighbouring properties. FI plant Load control details will be detailed in full within the project definition. Reference shall be made for load control – document CEOP8085. Typically, 11 or 22kV FI plants are indoor units are to be installed within the substation building. Where this is not possible, the FI unit shall be located in a separate weatherproof enclosure. Typically, 33 or 66kV FI plants have outdoor coupling units and indoor transmitter/control cabinets. Sound attenuating walls may be required to reduce impact to neighbouring properties. Disconnectors & earth switches Outdoor disconnectors and earth switches are to be positioned such that adequate clearance is maintained from other equipment whilst opening and closing via operating handles. Earth mats shall be installed at each operating handle. Current & voltage transformers Outdoor current and voltage transformers are to be positioned such that adequate clearance is maintained from other equipment and that they can be easily isolated for maintenance purposes. Rigid and flexible overhead busbar Busbars in outdoor switchyards shall generally consist of two types – round aluminium tube or stranded aluminium conductors. A damping conductor must be installed in all round aluminium tube. Every length of tube busbar is to have one free joint to allow for thermal expansion. Standard sizes to be used as shown in table 2 below, unless otherwise agreed to by the company. Description Outside Diameter Max Unsupported Length Material 100mm 8 metres Alloy 6101-T6 210mm² 18.8mm 4 metres AAAC 506 mm² 29.3mm 5 metres AAC CSA 100mm round x 4mm thick 19/3.75 stranded Al conductor (Neon) 61/3.25 stranded Al conductor (Uranus) A maximum of three (3) conductors shall be used for any one (1) phase conductor. Where earthing switches are not installed to earth busbar sections, flexible and solid busbars shall be fitted with earthing stirrups for connecting portable earth sticks. These stirrups shall be located PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 30 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 at both sides of all isolation points to provide protection of employees and equipment from inadvertent re-energisation, or induced voltages. The stirrup shall be approx. 25mm diameter with a connection area approximately 75mm long. A hand operated earthing attachment is required for connecting the portable earth stick leads on the closest steel structure. All aluminium busbars are to be left in its natural state, ie, no painting is to be carried out. 11/22kV transformer busbar to be insulated by approved method. Terminal palms on all busbar to comply with AS 62271-301. In any one installation, all main circuit terminal palms shall be of the same size to standardize connections. The following sizes shall be used in all cases except where approval has been given to deviate from these standards: Terminal 5 or 7 for currents up to 1250A(Preferred palm for most applications) Terminal 8 currents up to 2000A Terminal 9 for currents up to 3150A. If adaptor plates are needed to match the terminal palm design given above, consideration will be given to welding the busbar to the adaptor plate rather than connecting the busbar via bolts. Underground cables Standard sizes to be used as shown below, unless otherwise agreed to by Essential Energy. Description 11/22kV Transformer secondaries 22kV Transformer secondaries 11kV Feeder 22kV Feeder 11/22kV Auxiliary transformers (315kVA) 11kV Capacitor bank (7.5MVAR) 22kV Capacitor bank (7.5MVAR) 11/22kV Frequency injection 66kV Feeder 132kV Feeder Cable Type 630mm² XLPE (Cross Linked Polyethylene) Copper (Cu) single core 500mm² XLPE Aluminium (Al) single core 300mm² XLPE Cu or 500mm² Al three core 240mm² XLPE Al three core 95mm² XLPE Al three core 300mm² XLPE Cu three core 185mm² XLPE Al three core 95mm² XLPE Al three core 630mm² XLPE Cu single core 630mm² XLPE Cu single core Cables shall be installed with minimum separation of 250mm. All cables are to be separately supported adjacent to joints and terminations. Sufficient supports shall be provided throughout the route of all cable runs to prevent excessive strain being imposed on the cables. The spacing of supports shall not exceed one metre. A high voltage cable schedule shall be produced indicating cable routes throughout the substation yard. All types of cable termination kits, lugs and fittings are to be identified on this drawing, including product codes and quantities. Lightning protection equipment All points of change in impedance ie exposed incoming and outgoing lines and power transformer connections are to have surge arrestors fitted. The power transformer surge arrestors shall be installed as close as possible to the transformer bushings. Connection to surge arrestors are to be via straight flexible connections. Surge arrestors are not to be used as busbar supports. The company utilizes the rolling sphere technique with a radius of 30 meters for calculation of the area protected by lightning masts. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 31 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 The lightning protection drawing is to show the area of protection to minimum design heights of 7 meters for up to 66kV and 8 meters for 132kV substations. All equipment inside the substation fence, including buildings, is to be protected by adequate lightning masts. Earthing of equipment and structures Drawings detailing the specific earthing requirements of each type of primary equipment and structures shall be produced. The substation design group has developed a suite of template earthing detail drawings which shall be replicated as required. Labelling of primary equipment All indoor and outdoor primary electrical equipment shall be identified by labelling. The labelling of operable equipment shall be as shown on the single line diagram. The company’s procedure CEOS5033 defines the identification codes to be applied to all station operable equipment. The company’s procedure CEOP8042 defines the requirements for outdoor and indoor operational labels to be used in zone substations. Phase identification markers are required on all outdoor equipment. 5.6 Secondary system design 5.6.1 General The secondary system design package shall be designed in accordance with the relevant Australian standards and reference shall be made to the company’s documents - High Voltage Protection Guidelines, Design Guidelines for SCADA and DSA and Zone Substation Design Reference Manuals. The substation design group has prepared a suite of template drawings which are to be replicated as required. The secondary system design package shall provide all the required information for the installation and connections of control and protection equipment. The secondary system design package shall include design drawings specific for the project and will consist of: AC and DC circuit diagrams for the following (including but not limited to): AC and DC distribution panels; feeder control and protection; busbar control and protection; transformer control and protection; battery system control and protection; voltage transformer changeover scheme; metering; capacitor bank control and protection (if required); and frequency injection control and protection (if required). Low voltage and control cable schedules; Cable tray layouts; SCADA schedule; Control, protection & metering panel layouts (including panel label list); PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 32 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 Connection diagrams for the following equipment and associated control and protection panels (including but not limited to): circuit breakers; switchboards; power transformers; voltage transformer marshalling cubicles; busbar protection system; AC and DC distribution panels; disconnector & earth switch auxiliary switches; battery chargers; auxiliary transformers; metering equipment; fire detection alarm panels; capacitor bank (if required); and frequency injection (if required). Switchyard lighting layout; Secondary equipment schedules. 5.6.2 Low voltage and control cabling General A LV and control cable schedule shall be produced to indicate the types, sizes, lengths and locations of all cables. Identification Each control cable shall be identified with unique number. Typically cable numbers depict the operational number of the primary equipment and are detailed in the substation design reference documents. Control cables which have more than four cores, the individual cores shall be identified with numbers embossed in words and numerals at intervals of not greater than 75 mm. Identification shall be with black characters on white insulation. For power cables, the phase insulation shall be identified by colours of red, white and blue, with black neutral. Screening and earthing of control cables and protection relays To reduce the effect of transients and interference, all installations are to have AC, DC and SCADA wiring run in separate cables. Cables fitted with an overall screen, are to be earthed at one end only (preferably the source ends). Earthing conductors shall be stranded copper of minimum cross sectional area of 2.5 square millimetres with the standard green-yellow coloured insulation. All SCADA cabling shall be run in screened multi-core twisted pair cable. Pulsed output signals shall not be run in the same screened cable as digital input or analogue input signals. It is permissible to run digital input signals in the same cable as analogue input signals PROVIDED that the cores carrying the different signals are not in the same twisted pair. All protection relays will have the case and I/O cards earthed strictly in accordance with the manufacturer’s instructions. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 33 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 Cable Selection Cables shall be selected from those available on the company’s stores system. The standard control cables to be used in a typical Substation are: Conductor Stranding Use CSA No. of Cores Overall Screen 7/0.67 2.5mm2 2+E No VT secondaries 7/0.67 2.5mm 2 4+E No CT secondaries (except Tx LV) 7/0.85 4.00mm2 4+E No CT secondaries (Tx LV) 7/1.04 6mm2 4+E No CB heaters/yard GPOs Control cables 7/0.67 2.5mm SCADA cables 7/0.30 0.5mm2 DC supply cables 7/1.85 10mm2 4+E 10+E 19+E 20+E 4pr 8pr 2+E Telephone (UTP – unshielded twisted pair) 1/0.9 0.9mm2 Pr 2 Yes Yes No No Note: The cables sizes listed above are standard sizes only. The size of all cables must be checked for the appropriate current rating and voltage drop. The CT cable sizes are to be used except where the zone substation designer calculates that the loop impedance on the CT circuit is less than 1 ohm and confirms with the assigned protection officer for the particular project in question that it is adequate to reduce the standard CT cabling size. 5.6.3 Cable ladder General A cable tray layout drawing is to be produced highlighting cable tray routes throughout the substation. All types of cable tray, fittings, and bends are to be identified on this drawing, including product codes and quantities. Design requirements All cable ladders shall have a spare capacity of at least 25% of ladder capacity after all cables are installed. The route shall be designed to be clear of pipes and valves and shall not obstruct access to plant and equipment. The cable ladder shall be designed for straight lines parallel to walls and floors. Where cable ladders are installed one above the other the minimum spacing between each level of ladder shall be 300 mm. Where cable ladders are installed in plant rooms or across walkways the minimum clear height from floor or ground level to underside of ladder shall be 2.1m. Factory fabricated bends, risers, tees and crosses shall be used for all connections and changes of direction. All fittings shall maintain the specified minimum bending radius for the largest cable to be installed on the ladder run. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 34 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES 5.6.4 Amendment No: 8 Control and protection panels General The substation design group has prepared a suite of template control panel drawings which are to be replicated as required for every panel. Panel arrangement drawings shall detail all equipment mounting information, label information and provide a detailed material list required for the panel manufacture. Control panels shall be generally designed so that the front of the panel is used for the flush mounting of relays, meters, fuses, switches and provision at the rear of the panel for the termination of control cabling. The substation design group has developed a standard control and protection panel specification which shall detail the specific requirements for the panel types. Types of panels The type of panels to be designed shall be determined in the project definition. Typically the company has two types of control and protection panels: front entry/swing frame: Rear panel is fixed and all access is achieved via the hinged reinforced front door with 19 inch rack incorporated; and rear entry: Hinged door is located on the rear of the panel for all access. Front is fixed with 19 inch rack incorporated. New control panels shall generally be 2000 mm high, 600mm deep and 800 mm wide. Panels shall be mounted on a 100mm high plinth. Floor panels in the base of cabinets shall be constructed of aluminium plate. The company has many existing substations which have control & protection panels that have been constructed to various design standards. One of the most common panel systems is the Ex ECNSW tunnel board style using “E” type panels. The tunnel board has a large walk through design. Control panels face outward on both sides of the cabinet and are fixed. For modifications in existing zone substations it may be required to design and install new panels to match the existing system. Layout Control and protection panels shall have a clear delineation between the number 1 protection which will always be mounted at the top of the panel and the number 2 protection which will be mounted on the bottom half of the panel. All control functions shall generally be located at the very top of the panel. All panels except AC distribution shall utilise the 19 inch racking system for the mounting of equipment. For certain functions such as metering, half panels may be used as long as provisions are made so that the other half panel can be used at a later date. Panels shall be orientated so that AC panels and FI controllers are located remote from the SCADA panel. This is to prevent the possibility of interference in the SCADA RTU. The following panel grouping shall be used as a guide to configuring the panel arrangement within the control room: AC/DC supply panels; FI controller (SFU-K); general control and protection panels; and SCADA & communications panels. Usable voltages All new control panels shall have only one source of 240VAC. This is to supply the panel light. There shall be no possibility of live 240VAC exposed within the control panel without the use of specific tools, ie no fuse carriers or shrouded terminals. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 35 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 All other acceptable voltages shall be: 110VAC; 110VDC; 48VDC; 32VDC; and 24VDC. All exposed terminals on fuses and links connected to 110V AC supplies shall be protected with a clear perspex covers. Control panel lighting Each panel is to be fitted with internal fluorescent panel lighting. The panel lights are to be wired with one circuit of double insulated cables looped between each panel and are to be controlled by a switch mounted on the AC distribution panel. 5.6.5 Protection links and wiring The test link type shall be Eugaquip STL5 - M5 three (3) studs and the following colour code is to apply: PROTECTION LINK COLOUR CODE TABLE COLOUR BLACK PURPOSE DC trip inputs DC trip outputs DC supplies Trip isolation of local backup and CB failure protection schemes CT links WHITE VT links GREY RED The links are to be mounted so that if the sliding section is loosened, it will fall to the closed position. Links associated with #1 and #2 protections are to be segregated if mounted on the same panel and the following wiring conventions are to be adopted: CT and VT circuit links Connections from associated CTs or VTs are to be wired to bottom of the link. Connections to protection relays are to be wired to top of the link. DC circuit links Connections to and from adjacent panels are to be wired to the bottom of the links. Connections to associated relays are to be wired to the top of the links. Protection relay links All protection relays are to have test links in the AC and DC circuits for testing contacts and isolating supplies. 5.6.6 Fuses Panel mounted fuse holders shall be an NS offset tag type – Alstom Safeclip SC32. Fuses shall be HRC type complying with AS/NZS60269.1-2005. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 36 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES 5.6.7 Amendment No: 8 Control panel labels The substation design group has standard, unique numbers and descriptions to be used for each link and fuse on all control and protection panels. Label layout, arrangement and manufacture details can be found on the panel layout drawings in the suite of template control panel drawings. 5.6.8 Standard wiring code The substation design groups document Substation Design and Projects Wiring Code CEM7051, has been created to define the Standard Wiring Code. This manual is to be referenced when augmenting existing or creating new design drawings. The template drawings have been created using the standard wiring code. 5.6.9 Moulded Case and Miniature Circuit Breakers Moulded case circuit breakers (MCCB) with fault capacities of 10 kA or more shall comply with AS2184. Miniature circuit breakers (MCB) with fault capacities less than 10 kA shall comply with AS3111. All MCCBs shall be selected from the one manufacturer. The type and tripping characteristic of MCCBs shall be selected to ensure full discrimination between series combinations of MCCBs and MCBs at all fault current levels up to the maximum prospective fault level. MCCBs with rated frame sizes in excess of 200 A shall have inbuilt adjustable thermal and magnetic trip units with separately adjustable thermal and instantaneous settings. Earth leakage circuit breakers (residual current devices) shall consist of MCB with built in core balance earth leakage tripping mechanism where shown on the drawings. 5.6.10 Indication and control equipment Control Relays Relays shall comply with IEC60050-445 and shall be of the plug-in type unless otherwise approved. Plug-in relays shall be enclosed in a clear, polycarbonate dustproof housing with DIN rail mounting moulded socket for 8 or 11 round pins and fitted with spring retaining clip. Relays shall have 2 or 3 sets of silver plated copper wiping action changeover contacts in accordance with the drawings. Contact rating shall be a minimum of 4A, 240V AC to utilization category AC-11 for switching AC and 5A (inductive) at 125V DC for switching DC. For relays switching low level signals (less than 24 V DC or 5 mA) to Programmable Logic Controllers (PLC) or computers, gold plated silver contacts shall be used. The mechanical endurance shall exceed 20 million no load operating cycles. Relays shall be provided with status indication via LED connected across the coil as well as a mechanically actuated flag. Both shall be visible through the front of the relay case. Relays shall have an inbuilt surge suppression device permanently connected across the coil. Relays shall have a means to manually actuate the relay mechanism through the front of the relay case. Pushbuttons Pushbuttons shall comply with AS60947.5.1-2004. Pushbuttons shall be of “oil tight” design with coloured buttons and engraved label plate suitable for single hole mounting with a 22.5 mm hole (size D22 to AS60947.5.1-2004.1). Emergency stop push buttons shall have a large mushroom operator, coloured red, with approved mechanical latching device. Contacts shall be silver plated copper, wiping action type with a minimum rating of 4A, 240 V ac to utilization category AC-11. Pushbutton operators shall be of the following colours: Green - circuit breaker open; Red - circuit breaker close; and Black - reset. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 37 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 Indicator lights Indicator lights shall comply with AS60947.5.1-2004. Indicating lights shall be of “oil tight” design. The indicator light shall utilize single hole mounting with a 22.5 mm hole (size D22 to AS60947.5.12004.1). Lamp replacement shall be from the front only, without disturbance to wiring or lamp holder. The lens shall be coloured glass or heat resistant plastic. Each indicator light shall have an engraved label plate mounted directly above the lens. Indicator lights shall be of the LED type, operating at the same voltage level of the device to which it is connected. Where not identified on the drawings the lens colour of indicator lights shall be in accordance with the following: red - dangerous condition eg circuit breaker closed; green - safe condition eg circuit breaker open; yellow/amber - abnormal condition or fault; and blue or white - any other condition as approved. Selector switches Selector switches shall be fabricated in a modular form allowing multi-pole switches with switching configurations in accordance with the schematic diagrams to be made up from standard components. Switch bodies shall be moulded from self-extinguishing plastic materials. Terminals shall have captive screws and integral screwdriver guides. Switches shall have an escutcheon plate with an engraved label identifying the function of the switch in accordance with the schematic diagrams. Each switch position shall be engraved on the escutcheon plate. Direction of operation of switch handles shall comply with the following conventions: clockwise rotation - increase, raise or close and anticlockwise rotation - decrease, lower or trip. Contact systems shall be adequate for the voltage and current ratings of the particular circuit. Minimum ratings shall be: For general purpose control circuits operating on ac voltages the rating shall be 240 V, 5 A to a utilization category of AC14. Contacts shall be silver plated. For switches which operate directly in extra low voltage control circuits such as PLC or instrumentation inputs the rating shall be 24 V, 5 A or 110 V, 2 A. In addition where continued low contact resistance is considered essential to correct operation of the system the contacts shall be gold plated. Commonly used switches for standard secondary circuits have been identified and make, model and ordering information is detailed on the template panel arrangement drawings. 5.6.11 SCADA General The SCADA requirements for each project shall be identified in the project definition. Typical SCADA equipment would include a 48V or 24V battery system, DC distribution panel, SCADA RTU panel and a desk mounted HMI Touch screen. The company’s SCADA group are responsible for supplying the SCADA Panel and programming the RTU. The SCADA input and output points shall be connected serially or hard wired to the RTU. Microprocessor based protection relays shall be connected via serial communications. Refer to Essential Energy policy document CEOP8084– Design Guidelines for SCADA and DSA for more information. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 38 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 A SCADA schedule shall be produced to detail all hard wired inputs and outputs to be connected to the SCADA RTU. Information such as cable, core and wire numbers, a description of the function of each input and output and control routines shall be nominated. The substation design group has developed a template SCADA schedule with typical I/O points and it shall be used to create the project specific schedule. SCADA control routines The SCADA RTU’s may be required to perform control routines such as transformer voltage regulation, Tx parallel operation, cap bank control, SEF control, auto changeover schemes, CB supervisory open/close and CB auto reclose. 5.6.12 Transformer voltage regulation The standard voltage regulation scheme employed by the company utilises the SCADA RTU to perform the control routine. Typically the following equipment/devices are used: a voltage transducer is used to provide transformer voltage levels; tap Position encoders are installed in or adjacent to the transformer tapchanger cubicle; tapchanger inputs such as cam switch position, raise and lower limit switches, local/remote switch indication and TC motor alarms are wired to the SCADA RTU; and raise and Lower interposing relays are connected to relevant tapchanger circuits to perform the control functions An 110VAC monitoring meter relay is used to produce high and low voltage cut out to assist in preventing the voltage regulation (VR) scheme from raising or lowering the voltage outside acceptable ranges. 5.6.13 VT supply changeover scheme The voltage transformers which are not dedicated feeder VTs may require the secondary supplies to be controlled via a changeover scheme. These supplies are typically for suppling 110V AC to metering and 11/22kV feeder protection relays. The substation design group has developed a VT changeover scheme and template drawings which are to be replicated as required. 5.6.14 Substation metering The company requires statistical metering for substations, and in some instants revenue shall also be installed. The project definition shall outline the metering requirements and equipment specifications. The substation design group has developed a suite of template metering drawings which are to be replicated as required. 5.6.15 CT and VT secondary connections Marshalling cubicles Marshalling boxes shall be installed for all outdoor CTs and VTs. Each three phase set of outdoor CTs shall be provided with one local marshalling box mounted on the supporting structure. The marshalling box shall be complete with terminal strip, earth bar and gland plate. PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 39 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 Each three phase set of outdoor VTs shall be provided with one local marshalling box mounted on the supporting structure. The marshalling box shall be complete with fuses and links for secondary circuit protection and isolation, terminal strip, earth bar and gland plate. Busbar Protection (BBP) summation cubicles BBP summation cubicles shall be installed for all busbar protection schemes utilising outdoor current transformers located in the switchyard. Busbar schemes on indoor switchboards will not require a summation cubicle. BBP summation cubicles are to be located in an accessible situation in the switchyard and are fitted with isolation links for each set of CTs connected to the BBP scheme. Cubicle material specifications Marshalling cubicles shall have a degree of protection of IP65 be stainless steel construction. Gland plates shall be manufactured using aluminium. The substation design group has developed a suite of standard template drawings and a marshalling cubicle specification reference document which shall be detail the specific requirements for the different cubicle types. Earthing of CT and VT secondary circuits The voltage transformer 110V AC neutral conductor shall be earthed in the VT marshalling cubicle or in the 11/22kV switchboard protection panel. The secondary circuit for each core of every current transformer shall be earthed in one location only. Unused cores shall be shorted and earthed in the CT marshalling cubicle (if used) or at the secondary terminals. The non-polarity conductor for standard protection cores shall be earthed at the control and protection panel via a slide link. BBP cores shall be earthed at the summation point via a slide link. When schemes use a summation cubicle the earth point will be in the cubicle, if the CT summation point is on the BBP panel, the earth point will be on the panel. The non-polarity conductor for metering cores shall be earthed on the metering panel. 5.6.16 Substation auxiliary AC supply Each substation requires the design and installation of an auxiliary 415V AC supply. The 415V cabling from the auxiliary transformers is supplied to an AC distribution panel generally located in the control room. An AC changeover scheme controls the supply and ensures that auxiliary supply is available whenever possible. The substation design group has prepared a suite of template AC distribution scheme drawings which detail the required changeover schemes and distribution panels and are to be replicated as required. Panel arrangement drawings shall detail all equipment mounting information, label information and provide a detailed material list required for the panel manufacture. Circuit diagrams and connection diagrams shall detail all circuit wiring and control schemes including the automatic AC changeover scheme. All wiring is to be in accordance with SAA Wiring Rules. All switches and plug sockets are to be labelled with their circuit number. All conductors are to be multi-stranded. All devices required to be fitted with earth leakage protection, shall have that facility fitted. The battery charger supply protective devices shall either be motor start fuses or “D” curve circuit breakers. Auxiliary transformer LV panel The standard distribution panel in the pad mounted substation is an isolator, one fuse strip of adequate rating for station supply and a second 400A fuse strip to facilitate the provision of the oil filtering supply. The No.1 power transformer oil filtering supply shall be fed from the No.2 power PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 40 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 transformer. If the No.1 section fed auxiliary transformer is located adjacent to the No.2 power transformer, the oil filtering unit will be connected to the busbars by the 400A fuse strip with 250A fuses. Alternatively, a 3 phase outlet of suitable capacity fed from the alternate power transformer supply shall be provided as close as possible to the power transformers to allow oil filtering. Switchyard lighting Switchyard lighting shall be sufficient to provide illumination to allow employees to move around a switchyard safely, and operate equipment from ground level. The level of illumination in the switchyard shall be approximately 64 Lux at 1 metre. A switchyard lighting layout drawing shall detail all lighting equipment, switching, mounting information and provide a detailed material list required for the supply and installation of the lighting. Switchyard Power One single phase outlet and one three phase 32A 5 pin outlet is to be installed at each power transformer, one single phase outlet at each HV circuit breaker. 6.0 RECORDKEEPING The table below identifies the types of records relating to the process, their storage location and retention period. Type of Record Approved Branch Procedures, Workplace Instructions and Forms Storage Location Branch Process Coordinator where nominated, otherwise Divisional Process Coordinator Retention Period* To be determined * Content Coordinator must liaise with the Records Manager to validate the retention period is compliant with the relevant disposal authority. 7.0 AUTHORITIES AND RESPONSIBILITIES Manager Project Development has the responsibility for: Approving this procedure; Approving and archiving of branch level documents; Assigning appropriate responsibility to managers to carry out their functions in accordance with this procedure Informing employees and contractors of their responsibilities under this procedure; and Monitoring compliance with this procedure Substation Design Manager has the responsibility for: To act as the content coordinator for this procedure; Informing employees and contractors of their responsibilities under this procedure; Monitoring compliance with this procedure; Identifying interaction and relevance of other company policies and procedures with this document; ensuring a thorough review of this procedure is carried out in accordance with the company’s policy and procedure framework; and liaising with the relevant Process Coordinator to assist with complying with the requirements of the company’s policy and procedure framework PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 41 of 42 TRANSMISSION AND ZONE SUBSTATION DESIGN GUIDELINES Amendment No: 8 Employees have the authority and responsibility for complying with the requirements of this procedure 8.0 DOCUMENT CONTROL Content Coordinator: Manager Project Development Distribution Coordinator: Network Development Process Coordinator PO Box 5730 Port Macquarie NSW 2444 I Telephone: 13 2391 I essentialenergy.com.au CEOP8032 Uncontrolled if printed Page 42 of 42