Cable Installation Information

General
All cables must be installed to comply with the latest Australia Wiring Regulations.

Moisture
It is important that precautions are taken during installation to ensure that moisture is not permitted to enter the cable. Cut ends or opened areas must be protected from moisture at all times, including during pulling in. Cables, after cutting, must be re-sealed for storage, by an effective method such as a heat shrinkable cable cap.

Single Core Cables
The following points relating to single core cables should be noted:

1. Single core cables carrying the phase currents of a single circuit must be installed as closely as possible together, to minimise inductive reactance and voltage drop. The preferred formation for three phase conductors is a “trefoil” or cloverleaf pattern although flat touching formation is also acceptable. Sheaths should be in contact with one another in either case.

2. A single core cable generates an alternating magnetic field around itself which can cause large increases in voltage drop and power loss due to “transformer effect” when ferrous metal (iron and steel) is allowed to encircle the cable. Steel racking or ladder will not induce this effect, but the following must be observed:

• a. Cable cleats may be of wood, plastic, or nonferrous metal but steel saddles should not be used on single cores.
• b. Where three single phase cables pass through a steel bulkhead, they must all pass through the same hole. Where glanding is required, it is usual to cut out a panel and replace this with a nonferrous (metal or plastic) plate in which the three or four glands are mounted.

Cable Support
Under fault conditions, single core cables used as phase conductors in a multi-phase system may be subjected to large electromechanical forces which tend to drive them apart. Generally, properly designed cleats spaced at 1500mm intervals will provide adequate support to the cable under normal operating conditions. However special consideration may be required if fault currents in excess of 15 kA are anticipated.