All ducting/cables shall be bedded, haunched and surrounded in accordance with the designed standard and the manufacturer’s specifications.
CS-21.6.1 Pipe/Cable Laying
Ducts/cables shall be accurately laid to the lines, levels and depths as shown on the approved drawings (as applicable).
All column installations shall be provided with approved internal termination junction boxes for terminating the lighting circuits. These are to be located at the gear openings of each column. Underground jointing will not be permitted.
CS-21.6.3 Termination, Joints and Connections for Underground Cables
- For underground cables the following jointing types shall be used:
- In-line joints at 11kV and 33kV - heat-shrink polymeric.
- For terminations at 11kV and 33kV - heat-shrink polymeric and cold shrink for single core 25mm² 11kV terminations.
Only Raychem brand terminations with shrink or re-enterable roll-on boots are approved for use with ABB SD switch units.
- In-line joints 400V - heat-shrink polymeric endless rubber sleeve with mastic.
- Tap-offs 400V - Resin-filled joint box normally (only in retro-fit situations where 400V reticulation is already in place).
- Cap joint compression in above ground connection box.
- For all the above joints and terminations except for the 400V resin-filled box, the conductor is joined or lugged using compression techniques.
- The 400V tap-offs from multi-core cable make use of a three-phase plus neutral insulation piercing connector and the resin-filled box noted above.
- Where aluminium cable is to be terminated onto an overhead line, an in-line compression joint shall be made using a connector blanked off in the centre to prevent entry of moisture into the cable by capillary action.
- Bi-metal connectors and lugs shall be used where appropriate.
- Underground connections to neutral screen cables are not permitted.
- For more information refer to UND 006: Jointing of overhead and underground cable.
CS-21.6.4 Low Voltage Cables
Table 1: Low Voltage Cables for New Distribution Lines lists low voltage cables to be used for new distribution lines.
Table 1: Low Voltage Cables for New Distribution Lines
|Cores and Size (mm2)
||Insulation and sheath
||Single Way in Ducts
|4 x 185
||Distrubution line and transformer looms
|4 x 120
|| Distrubution line and transformer looms
|4 x 95
|4 x 70
|4 x 70
||Distrubution line tee-off to customer
|1 x 16NS or 1 x 10NS
|1 x 4
CS-21.6.5 Column Installation
- Embedding depths for ground-planted columns shall comply with the manufacturer’s recommendations, section 6.0 of AS/NZS 4676 Structural Design Requirements for Utility Service Poles and TNZ M/19 Specification For Tubular Steel Lighting Column. A tolerance of ± 50mm in embedding depth is allowable. Columns shall be installed so the centreline of the columns is vertical within ± 0.5° and the outreach arm is perpendicular to the road. The column shall be oriented so that safe and convenient access is available to the gear access opening. Column foundation excavations shall be backfilled with suitable material either as excavated or imported and compacted in layers not exceeding 300mm.
- Concrete backfill shall not be used unless wind stability cannot be achieved by rammed earth backfill. It must be specifically approved by the Engineer/Council. If concrete backfill is used a cable duct must be provided to allow cabling to enter the column base. The duct shall be of sufficient diameter to allow for an additional cable.
CS-21.6.6 Outreach Brackets
- Streetlight outreach brackets shall be constructed as detailed on the manufacturer's drawing standard for the type of structure being used. Brackets are to be manufactured from steel and hot-dip galvanised. Alternative bracket materials may be used subject to approval from Council.
- The bracket backing-plate shall be attached by using the 4-bolt clamp system which has been designed to accommodate the older-style concrete poles with no holes provided for bolting. All brackets shall be bolted top and bottom of the plate. The bolts shall be 12mm diameter minimum.
- Stainless steel strapping will not be accepted.
CS-21.6.7 Wiring of Columns
- Any work undertaken on the streetlighting electrical system shall be undertaken by a Contractor authorised to do so by the utility operator.
- The equipment tray on the lighting columns shall be wired in accordance with the manufacturer's drawing standard for the type of structure being used.
- HRC fuse holders only shall be used. In areas where the mains cables are not looped in and out of the column it shall be permissible to terminate the phase conductor directly into the fuse holder. Crimp or compression lugs shall be used on all bolted terminations. Earth studs, washers and nuts shall be made of brass. Dropper cables from the luminaires shall be copper twin and earth TPS with a minimum cross-sectional area of 1.5mm².
- All cables connecting to a column shall be looped into the column using an approved connector. T-jointing below ground shall not be permitted unless specific approval is given by the local electricity network utility company.
- The fuses shall be appropriate to the wattage of the lamp and the incoming supply must go to the top of the fuse.
- The screen of the Neutral Screen cable shall be sleeved at each end.
- All cables from the column shall be terminated into a gyro-box, not into the existing underground pilot lines.
- Where a column is to be cabled to an overhead circuit pole the cable shall be installed in high impact PVC conduit secured up the pole with stainless steel bandit strap to the level of the 400V cross-arm. The cable-tails shall be terminated into the fuse supplied and fitted by the Contractor at the 400V cross-arm.
- All exposed PVC conduit shall be coloured grey.
CS-21.6.8 Wiring of Luminaires Attached to Existing Poles/Structures
Cables from each individual luminaire shall be connected via a fuse to the overhead wire. This becomes the isolation point for maintenance contract works. The Contractor shall install the cable from the luminaire to the fuse holder and the fuse holder itself. The Contractor shall note the requirement for any work on the electrical system to be carried out by the local electricity utility operator.
- All columns shall be earthed.
- Concrete columns shall have all exposed metal work earthed onto a separately driven earth spike with an earth resistance no greater than 10ohms.
- Steel or metal columns need not be separately earthed if the earth resistance of the standard itself is less than 10ohms.
- All metal-work shall be bonded together and to earth.
- Continuity shall be ensured between the cable and the equipment earth by continuity bonding.
- All cable bends shall be followed by a minimum of 50mm of straight cable before the cable enters a gland.
CS-21.6.10 Stockpiling of Streetlight Poles
Where required in the contract, streetlight columns shall be removed from the site and transported to the Council stockpile area at Te Maunga. Access to the stockpile yard shall be obtained through application to the Council.
Definitions in this section