INFRASET Reticualtion Poles Assist with Safe Power Delivery
Prestressed concrete poles, manufactured by INFRASET Infrastructure Products, have been successfully deployed for medium and low voltage reticulation at most of City Power’s electrification projects in City of Johannesburg including, the Alexandra metering project and the Pennyville housing project.
The Alexandra metering project entails the restoration of electricity supply to acceptably safe levels for both the customer and City Power, as well as the removal of illegal connections. The project forms part of the normalisation of the Alexandra electricity network and the installation of remote pre-payment metering and energy system for new and existing houses.
The Pennyville greenfield project entailed supplying electricity to approximately 3,000 newly constructed housing units. Three sizes of housing units, 36m², 40m² and 42m² variants were built in Pennyville, mainly as single-storey units, but also as double and triple storey units.
In most instances the poles were deployed using stayless technology, for example no stays were necessary to support the poles. To date a total of 2,526 reticulation poles have been supplied for the Alexandra metering project. These comprised: 1,220m x 7m 4kN poles, 417m x 7.2m 10kN poles, 710m x 7.5m 20kN poles, 117m x 10m 8kN poles and 62m x 11m 8kN poles. The poles were supplied to the three installation contractors, Malangeni Construction, Karebo Engineering and Tshepang Electrical.
INFRASET supplied 1,771 poles to pole installation contractor, Kusokhanya Electrical, for the Pennyville project. These comprised: 744m x 7m 4kN poles, 290m x 7.2m 10kN poles, 399m x 7.5m 20kN poles and 338m x 10m 8kN poles.
The poles are used to support the overhead arial bundle conductor (ABC) to feed power to individual housing units on both projects.
INFRASET railway products manager, Sizwe Mkhize, says that all the poles were manufactured with earthing bars (no additional earth conductor required) to protect them against lightning. He notes further that the high strength-to-weight ratio of prestressed electrification poles sets them apart from poles made from other materials.
“The resilience of prestressed concrete poles enables them to recover from the effects of a greater degree of overload than any other type of structural material. And experience worldwide has demonstrated that during their lifetime, prestressed concrete poles are maintenance-free, a major advantage. Unlike other materials, concrete suffers no loss of strength over the years, being resistant to insects, fire, rot and corrosion.
“Our poles have an attractive rectangular tapered I-section design and are cast in high-strength, high-density concrete with a smooth finish. They are functional yet relatively light, and this makes them convenient for contractors to handle,” says Mkhize.
INFRASET poles are manufactured at ISO 9002 accredited factories in a wide range of strengths and sizes to fill most requirements in MV and LV lines. They also comply with Eskom DTC 0106 and various SABS and Spoornet specifications.