Founded in 1954 by a group of recognised leaders in the repair and servicing of electric motors, Marthinusen and Coutts (M&C), a division of ACTOM,  has grown into a trusted service provider for the remanufacturing, repair and maintenance of rotating equipment, most notably for the rewinding of medium and low voltage AC and DC motors, generators, transformers and coils, along with advanced testing.

“We have extensive capabilities in power generation and mechanical engineering from seven well-equipped repair workshops in Southern Africa that now employ almost 450 people,” says M&C marketing executive Mike Chamberlain.

As well as the 9 500 m² Cleveland workshop in Johannesburg, M&C has a 

14 000 m² workshop in Benoni and a facility in Rustenburg. “We also operate through other ACTOM outlets across Africa, including Kitwe in Zambia, GEC in Harare, Namibian Armature Rewinders in Walvis Bay, amongst others,” he says.

“As well as being a leading repair business for all sizes of motors and generators, we also have a sister division on the mechanical side, ACTOM Turbo Machines, for repairing and re-engineering turbines and all types of large rotating machines,” he adds.

The Difference

“We can quickly respond to customers’ needs, be they onsite repairs and refurbishments of large motors or motor/generator rewinding and refurbishments at one of our facilities.”

For very large machines, the Benoni facility includes a 140 t Wagner lathe that can accommodate a 40-t, 11-m workpiece with a swing of 3.2 m. “We have also invested in specialised equipment and tooling for coil retaining ring removal, and we have a 90 t crane capacity and 1 000 t hydraulic presses for very large salient pole coils used for hydro and synchronous generators. At our Cleveland operation, we have the best-equipped rotating electrical machines load test facility in Africa and a 32 t balancing machine.

For windings, four insulation systems can be accommodated, along with three different vacuum pressure impregnation systems for void-free insulation, which enhances the dielectric and mechanical strength of the windings and delivers improved thermal conductivity.

“We offer full load testing of HV, LV and DC equipment, and onsite diagnostics, including electromagnetic core imperfection detection testing; turbine vibration analysis; partial discharge monitoring, and rotor flux analysis, amongst others. 

“We also have a highly skilled and well-equipped field service team that offers 24-hour field service support for breakdowns and continuous improvement programmes for our customers,” Chamberlain explains.

Notable Projects

M&C installs, services and repairs gearless mill drives (GMD) across the continent and as far as Panama and Indonesia. Chamberlain describes an installation of new GMDs at copper mines. A Perth-based mining client has mines all over the world, including in Kansanshi and Kalumbila, which are both in northern Zambia, and Minera Panama.

M&C was contracted to interconnect the electrical sub-assemblies for nine new ABB GMDs for a copper project in Panama. This mine’s life is estimated at more than 30 years, and it produces copper, gold and molybdenum, says Chamberlain, adding that M&C has become the preferred provider of GMD services to this mining house.

On the power generation side, he cites a success at the N’Zilo hydroelectric power station on a 26 MW, 18-pole stator rewind for a vertical AC synchronous generator in the DRC, a very remote and isolated location.

“Further complicating the work, the stator was lap-wound, which required a high level of expertise. 

The Reverse Engineering Approach

M&C’s design team, led by Rob Melaia, is the top motor design team in Africa. “They check the winding design of every motor/generator we rewind, looking for ways to improve reliability and performance. Our engineering teams have the experience and ability to apply practical insights gained from years of repairing and analysing motors across various industries.

In 2012, ACTOM acquired Marthinusen and Coutts. ACTOM is an industry leader and the largest manufacturer, solution provider, repairer and distributor of electro-mechanical equipment in Africa, and Marthinusen and Coutts is an independently run division of ACTOM.