1. Purpose and Scope
This technical specification sets out the requirements for the manufacture, testing at works,
supply and delivery of aluminium castings, pole caps and pressed letters and numerals for
use on overhead electricity distribution systems in a totally exposed environment.
2. References
2.1 Applicable Standards
All items shall be designed, manufactured and tested with the relevant parts of the following
Standards and all amendments issued from time to time except where varied by this
specification.
| STANDARD | TITLE |
| AS 1154 | Insulator and conductor fittings for overhead power lines |
| AS 1734 | Aluminium and aluminium alloys – Flat sheet, coiled sheet and plate |
| AS 1874 | Aluminium and aluminium alloys – Ingots and castings |
| AS/NZS ISO 9001 |
Quality management systems – Requirements |
3. Drawings
3.1 Drawings by the Purchaser
The drawings listed in Appendix A.1 shall be read in conjunction with, and shall form part
of this technical specification.
3.2 Drawings by the Tenderer
The Tenderer shall supply with the tender, detailed drawings or pamphlets of the items
tendered.
4. Service Conditions
The items will be exposed to the following environmental conditions:
| Temperatures | 45oC summer day time -5oC winter night time |
| Solar Radiation Level | 1 000 W/m2 with high ultraviolet content |
| Precipitation | Tropical summer storms with gust winds above 160 km/h, and an annual rainfall in excess of 1 500 mm |
| Humidity | Extended periods of relative humidity in excess of 90%. |
| Pollution | Areas of coastal salt spray and/or industrial pollution with equivalent salt deposit densities in the range 2.0 to 3.0 g/m2 |
5. Design and Construction
5.1 Castings
Castings shall be manufactured from aluminium material grade BB 401 (or equivalent) to
AS 1874.
Full details of the type of aluminium to be used shall be submitted in the tender.
5.2 Workmanship
Castings shall be clean, free from harmful inclusions, blow holes and all other defects and
all fins shall be removed. The dimensions shall be in accordance with the dimensions
shown on the appropriate QESI/ERGON drawings or AS 1154.
All holes to accommodate bolts on pins in castings, shall be accurately drilled or cored
parallel sided, and in the same straight line.
5.3 Identification Reference
Where specified, all castings shall be permanently marked with the appropriate
identification reference and with the manufacturer’s name or trademark.
5.4 Mechanical Ratings
Castings shall have mechanical ratings as specified on the appropriate QESI/ERGON
drawing.
5.5 Pole Caps
Pole caps shall be cut from aluminium plate with alloy designation 1200 (or equivalent) to
AS 1734. The temper shall be 0.
Full details of the grade of aluminium plate to be used, shall be submitted in the
tender.
Mill finish only is required on pole caps.
5.6 Pressed Letters and Numerals
Letters and numerals shall be pressed from aluminium plate with alloy designation 1200 (or
equivalent) to AS 1734. The temper shall be 0.
Full details of the grade of aluminium plate to be used, shall be submitted in the
tender.
The aluminium sheet shall be of thickness 0.5 mm ± 0.05 mm and the letters/numerals shall
be of height 50 mm ± 2 mm. The letters/numerals shall be supplied with 2 off 4 mm holes
for mounting on to timber using screws or clouts.
The edges of the finished letters/numerals shall be smooth and free from any sharp
projections.