South African electrical and mechanical services company Marthinusen & Coutts, a division of Actom, has bagged a contract for a second synchronous condenser unit for the state electrical utility Société nationale d’électricité (SNEL) in the Democratic Republic of Congo (DRC).

The new order follows Marthinusen & Coutts rehabilitating an identical 70 MVA synchronous condenser for Unit 1, which form critical components of the DC/AC converter station in Kolwezi in the DRC.

Power is transmitted from Inga hydroelectric power station in the north, and converted from AC to DC. This is then transmitted to Kolwezi and converted back to AC, with the power feeding the energy-intensive Copperbelt in the Katanga Province.

Richard Botton, divisional CEO, at Marthinusen & Coutts, explained: “Our initial contract was a stator rewind for Unit 1, in addition to some minor repairs to the pole coils and complete damper (amortisseur) winding change out. Based on the success of the first unit, we were awarded the second unit.

“We have completed the stator rewind for Unit 2 and are in the process of manufacturing four new pole coils and reconditioning a further four in our Cleveland, Johannesburg premises.”

Consortium of suppliers

Marthinusen & Coutts is working with a range of suppliers and OEMs on the project.

The stator coils were imported from National Electric Coil of Texas in the US, with additional components sourced from GE Canada.

A modular arrangement was adopted due to the size of the machines, with full assembly taking place on site.

The condenser has a stator inner diameter of 2.4m and a core length of 3m, while the rotor weighs 95 tonnes and the stator weighs 98 tonnes.

This immense weight and size meant that Marthinusen & Coutts had to supply an on-site solution for SNEL. Challenges included the total lack of facilities on site, with no access to either cranage or workshop facilities.

All the necessary equipment and tooling was shipped up from Johannesburg in four containers, which Marthinusen & Coutts will leverage over the long-term to provide an integrated service for power generation and mining clients in Africa.

African opportunity

Commenting on Marthinusen & Coutts’ long-term strategy to become a preferred integrated electrical and mechanical services provider for the mining industry and other industrial sectors in Africa, Mr Botton said: “With the constraints on power supply being experienced in the DRC in particular, we are now in a unique position to become a preferred solutions provider for such critical projects.

“This means our customers will have access to our technology, skills base and experience in a one-stop service.”

Marthinusen & Coutts started work on the second condenser unit in March this year and is aiming for completion by December.