Johannesburg — POWER and automation group ABB SA has won an R85m contract from Johannesburg electricity supplier City Power to supply medium-voltage ring main units.

City Power's investment in the power distribution products comes at a time when the power utility has been criticised for unreliable supply.

The power supplier, on the other hand, has partly blamed power cuts on ageing infrastructure.

ABB said yesterday that under the three-year contract, it would deliver 11kV medium-voltage metal-enclosed freestanding ring main units to City Power. Ring main units are switchgears that distribute electrical power.

City Power acting MD Silas Zamu said the power utility wanted to ensure the new switchgear had been tested to the latest International Electrotechincal Commission (IEC) standards.

The IEC is the international standards and conformity assessment body for all fields of electrotechnology. "ABB was the first to test to these standards in SA for freestanding RMUs (ring main units)," the company said.

The IEC 61330 test proved public and operator safety in the event of a power failure in the enclosure, it said.

ABB said the contract also included the provision of other equipment such as kiosks and plinths.

The company said about 200 units a year would be used, mainly in new developments and in the replacement of oil-based ring main units.

With oil-based ring main units reaching the end of their life cycle, switchgears presented a safer option, ABB said.

City Power has said that more than 70% of electricity cuts in the city were caused by the ageing infrastructure, some of which dated back to the 1940s.

It has embarked on Operation Vuselela, a five-year project to upgrade its network. Under the initiative, City Power has said it will spend about R2bn, an average of R400m a year.