Field Instruction. Any registered training organisation UETTDRCJ21A Lay ESI electrical cables. Before commencing work:

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1 6.10 Cable Installation Purpose This field instruction outlines the minimum cable installation requirements for all Horizon Power Workers, including Workers operating, servicing, and/ or maintaining (MPS) Micro Power Systems electrical equipment (inclusive of all generating methodologies) for the following activities; laying cable pulling cable bedding cable backfilling cable trenches Note: This work practice must be read in conjunction with the following: Main Roads Western Australia - Utility Providers Code of Practice for Western Australia (1 February 2010) Underground Distribution Schemes Manual (UDS) Underground Cable Installation Manual (UCIM) Familiarity with the above manuals is essential for personnel undertaking cable laying activities on behalf of Horizon Power. Safety Before commencement of work, a risk assessment must be carried out using the Risk Analysis Procedure (OSH ), to identify and document the hazards and risks associated with the task and ensure appropriate control measures are implemented. It is important that, appropriate control measures must be identified, documented and implemented in order to control hazards to As Low as Reasonable Practicable (ALARP). Authorisation Personnel performing cable installation work on Horizon Power worksites must conform to field instruction 1.3 Construction site access minimum requirements. The person in charge of cable installation at the worksite must, in addition to the above, have a Cable Layer authorisation. In order to achieve this authority, personnel must have attended and passed: Any registered training organisation UETTDRCJ21A Lay ESI electrical cables. Before commencing work: Ensure that all personnel comply with the minimum personal protective equipment (PPE) requirements when handling, loading, excavating, laying or pulling cables (see FI 2.6 Worksite Clothing / PPE Requirements) CS# FI 6.10 Cable Installation Page 1 of 10

2 Conduct a risk assessment and job briefing to consider the following: shoring excavations confined spaces vehicle and pedestrian traffic management using machinery (for pulling cable) work near other underground and overhead services stability of any structure near excavations public safety additional PPE requirements Note: Livestock behind fences must be kept secure. Private property must not be damaged. Services must not be damaged. If trees in the road verge must be pruned, the pruned limbs must be sealed and left in a reasonable condition. Instruction Planning All work planning must take place before excavation begins. The following must be notified at least five days before work commences: Main Roads WA Railway services Local shires Councils and affected public Use the Dial before You Dig service to obtain information from all utilities about the location of existing underground services within the proposed area of work. When planning to install new cable, the following site access requirements and limitations must be considered: Environmental impact Private property or utilities (gas, telecom, rail, etc.). Other Horizon Power services (overhead, underground). CS# FI 6.10 Cable Installation Page 2 of 10

3 For more information go to: Main Roads Western Australia - Utility Providers Code of Practice for Western Australia (1 February 2010) AS Installation of underground utility services and pipelines within railway boundaries Note: Pavement or any constructed portions of any road reserve must not be broken to any extent without prior approval. For more on this, see the Underground Cable Installation Manual (UCIM), Section 16.4 Restoration of Surface: Excavation and Directional Drilling The requirements for excavation and directional drilling are covered in FI 6.4 Excavation Work and Directional Drilling, and the Underground Cable Installation Manual (UCIM) Ploughing Ploughing technology allows cables to be ploughed into the ground with an envelope of clean backfill sand. Ploughing equipment has the capability of installing cables in the following arrangements: o o Three single core cables (not twisted) in flat or trefoil (triangular) formation. As a minimum, cores must be transposed at every drum change. Triplex (twisted) The cable configuration must be surrounded with clean sand that is free of rocks and other hard formations: o o o 150 mm underneath the cable 50 mm on either side of the cable 300 mm above the cable Lay orange marker tape over the clean sand, as described in the Marking the ploughed cable route section, below. Fill the trench and compact to ground level with remaining material (ensure that stones and rocks have been removed) CS# FI 6.10 Cable Installation Page 3 of 10

4 Marking the ploughed cable route Permanent above-ground cable markers must be installed along a cable route as described in Table 1 below. Table 1 Cable Marking Requirements Alignment category Description Marker tape required? (300 mm above cables) Above ground cable markers required? A Cable within the standard mm alignment Install cable at a depth of 850 mm. Use orange marker tape above cable. Yes No B Cable within the m alignment Install cable at a depth of 850 mm. Use orange marker tape above cable. Yes No C Cable outside road reserve (in remote area where there are no other services or infrastructure in the vicinity) Install cable at a depth of 1200 mm. Use orange marker tape above cables and above ground cable markers. Yes Yes When markers are required (per Table 1, above), they must be placed: on either side of the road at the crossing point wherever a cable crosses a boundary (e.g. road reserve property boundary, etc) and as close as possible to the cable installation For cables in paddocks and open spaces: place markers so that the impact or damage to agriculture (including livestock) is kept to a minimum place markers at the boundaries if a cable has to cross a paddock Markers should also be placed: to signify a change in direction of the cable route so that adjacent markers are visible from each other at a maximum distance of 150 m apart Cable Alignments If cables are placed on alignment marker tape must be placed above the clean sand. The marker tape must be wide enough to cover the cables. If cables are placed off alignment (outside the mm alignment or the m alignment) prior approval from Horizon Power and any other affected utilities must be obtained. CS# FI 6.10 Cable Installation Page 4 of 10

5 If cable is out of the nominal mm or m alignment use heavy duty ducts to provide mechanical protection. If off alignment cables are buried direct cable cover slabs must be placed on top of 75 mm clean sand above the cable so that they overlap the width of the cables. This is followed by a further layer of clean sand to a depth of 300 mm above the cable and then marker tape. Note: For more information, see: Main Roads Western Australia - Utility Providers Code of Practice for Western Australia (1 February 2010). Underground Cable Installation Manual (UCIM), Section 10 Cables on and off Alignment Underground Distribution Schemes (UDS) Manual, Section 5 General Design Policies Handling Cable Drums Cable drums and cable are easily damaged through poor handling. Drums must be carefully loaded and handled using either: A forklift (with tines long enough to reach under both drum flanges) A crane (use spindles through the drum centre holes in conjunction with crane slings, lifting beams or spreader bars to prevent side pressure on the drum flanges) Never drop cable drums off a vehicle. The rolling of cable drums must be kept to a minimum. On delivery, visually inspect the cable drum for damage. Ensure that the cable end seals are intact. Cables must be returned to the supplier if the armouring, serving or sheath is: damaged corroded Positioning the drum Align the drum in the direction of the cable pull. Suitably mount the drum on purpose-built jacks, trailer or stands (a stable base must be provided for the drum during pulling). Spool the cable off the top of the drum. Check the drum flanges and remove any protrusions such as nails and splinters that could pierce the cable sheath. Ensure that the cable does not rub against the drum flange. Ensure that the drum is level and rotates freely and evenly. CS# FI 6.10 Cable Installation Page 5 of 10

6 Provide adequate barricading around the drum to prevent unauthorised access. Note: Cable may be pulled off the bottom of the drum if there are space restrictions. Ensure that the reason for doing this is recorded on the risk assessment. Laying Cable Laying or pulling cable into trenches or ducts presents a risk of damage to the outer sheath of the cable. Also, bending a cable beyond a certain limit can damage the insulation which may result in shortened life or faults (see the cable manufacturer s instructions for minimum bend radii). Ensure that there is someone monitoring the drum during the pull to prevent overrun (two-way communications must be in place). When pulling cables, cable rollers must be used as they will: provide protection from abrasion assist with pulling cable around corners reduce friction and pulling tension In all instances, cables that are being drawn into place must be kept clear of abrasive surfaces by suitable means (e.g. rollers) to prevent any damage to the cable sheath. The cable must be placed in the trench without sustaining abrasion damage and without allowing rocks, etc. to fall into the trench and onto the cable. During cable installation, ensure that no twists, knots or kinks are formed. If the cable is being flaked directly into its final position in the trench and is not being pulled (i.e. the drum is moving) then rollers, etc. are not necessary. The cable must still be laid onto the required 150 mm of clean sand bedding (see the Bedding cable section, below). Pulling cable through ducts The cable outer sheath must not be damaged when pulling cables through ducts. A flared or belled entry must be used at the entry end of ducts during pulling to prevent damage to cable. For more information, see Underground Cable Installation Manual (UCIM), Section 13 Conduits Note: When pulling cable into a duct: It is recommended that personnel use specialised conduit rollers or flutes. Use a suitable lubricant to reduce friction between the cable and the duct. CS# FI 6.10 Cable Installation Page 6 of 10

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8 Pulling Tension Pulling tension must be regulated according to the size and type of cable. See the cable manufacturer s instructions for maximum pulling tensions. Pulling tensions can be limited using: breakaway swivel rated to the cable (pulling fuse) pre-set winch tension rated to the cable dynamometer (must be monitored) force gauge (must be monitored) Pulling speed must be limited to avoid drum overruns and damage to the cable. Pulling Methods When using power winches, there are four methods of attaching cable to the winch rope. The most suitable depends on the following: type of cable size length construction Armour pulling Uses the armour wires extended beyond the end of the cable and formed into a pulling eye. Stocking pulling Common for cables up to 33 kv. Care must be taken to not apply too much tension and stretch the cable sheath. Nose pulling For long cables and large cross section cables. Uses pulling eyes attached to the cable conductors. Used when stocking pulling exceeds sheath strength. Bond pulling Cable is lashed to steel wire rope to distribute pulling tension throughout its length (bonded). This method is only used when end pulling tensions for the cable are exceeded. Bend Radii Use rollers to reduce friction and provide an adequate bend radius when pulling cable around corners. Trenches must be wide enough to allow for the minimum installing bend radius (see the cable manufacturer s instructions for minimum bend radii). Cable sealing Cable that is not going to be terminated immediately must be re-sealed if the seal is damaged after pulling and/or removing any pulling eyes. Bedding cable The minimum cover for cables is 850 mm. This will ensure that a depth of 750 mm at the joints is maintained. CS# FI 6.10 Cable Installation Page 8 of 10

9 The cable configuration must be surrounded with clean sand that is free of rocks and other hard formations: 150 mm underneath the cable 50 mm on either side of the cable 300 mm above the cable For cables vertically above one another, the sand filling between them must be 200 mm and the top cable must be covered with a further 300 mm of soft sand. Backfilling When backfilling a cable trench, ensure that: the backfill material is free of stones, rocks and paving material rubbish, pipe or cable off-cuts are not buried in the trench the backfilled material is compacted in layers to the same density as the surrounding soil the backfill is the same level as the original, unexcavated land all surplus spoil is removed from site Surface restoration Any pavement or constructed surfaces that are damaged during excavation must be restored in accordance with the Restoration and Reinstatement Specification for Local Governments in Western Australia (see the References section, below). Restoration of surface includes restoration of footpath of all type of materials (e.g. bitumen, brick paving, liquid limestone) Where cement footpath slabs have been removed to allow cable trench excavation, they must be reinstated in accordance with the local council's requirements. All damage to private property must be repaired (within reason) to the landowner s satisfaction, this may include: trees (limbs cut, sealed and debris removed) fences and walls (protected from damage) structures (protected from damage) paving (restored back to former condition) reticulation systems (repaired) underground services (repaired) For more on this, see Underground Cable Installation Manual (UCIM), Section 16 Reinstatement, and Section 17 Damage to Property CS# FI 6.10 Cable Installation Page 9 of 10

10 References Occupational Safety & Heath Act 1984 Occupational Safety & Health Regulations 1996 SHMS OSH Job Risk Analysis (JRA) Procedure SHMS OSH Personal Protective Equipment 1.3 Construction Site Access Minimum Requirements 2.5 Other Personal Protective Equipment 2.6 Worksite Clothing / Personal Protective Equipment Requirements 2.23 Job Hazard and Risk Management (JRA) 6.1 Working Adjacent to Gas Mains 6.4 Excavation Work and Directional Drilling Section 9 of the Horizonpower s Instruction Manual Environmental UETTDRCJ21A Lay ESI electrical cables - Registered RTO Training AS (Installation of underground utility services and pipelines within railway boundaries) Main Roads Western Australia - Utility Providers Code of Practice for Western Australia (1 February 2010) Restoration and Reinstatement Specification for Local Governments in Western Australia 5E PDF Underground Cable Installation Manual Underground Distribution Schemes (UDS) Manual CS# FI 6.10 Cable Installation Page 10 of 10