4.4 Selection of cables
4.4.1 General
4.4.2 Conductors
4.4.3 High voltage cables
4.4.4 Low voltage cables
4.4.5 Neutral connections
4.4.6 Route selection
4.4.1 General
Cables used in underground cable systems should comply with an appropriate Australian Standard.
In addition, consideration should be given to the following:
- safety;
- environmental conditions;
- life cycle assessment;
- insect or vermin attack;
- vibration;
- ultraviolet degradation;
- economic, security and reliability factors;
- forces incurred during installation;
- forces incurred during the service life of the cable; and
- corrosion protection of armouring and sheathing.
4.4.2 Conductors
When selecting the cross-sectional area of the conductors of an underground electric cable, keep in mind the:
- prospective load;
- voltage drop;
- fault currents;
- fault clearing times;
- proximity of other heat sources, e.g. cables; and
- thermal properties of the surrounding environment.
4.4.3 High voltage cables
High voltage underground cables should have integral metallic conducting screens or sheathing or both.
4.4.4 Low voltage cables
All conductors including the neutral should be insulated to the full voltage rating of the cable. Bare neutral conductors should not be used.
4.4.5 Neutral connections
The connections between neutral conductors should be designed and installed to ensure the connections maintain the required conductivity during the service life of conductors.
4.4.6 Route selection
Basic factors to be considered during the selection of an optimum cable route are set out in ESAA C(b)2.
In addition, consideration should be given to:
- EMF mitigation;
- Environmental impact issues.
Last updated July 22, 2005
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