The South African market is steadily recognising Marthinusen & Coutts’ capabilities in the area of restoration and modernisation of old electrical equipment to an “as new” status; this capability is also associated with significant cost savings.The latest company to make use of these services is Impala Platinum, who recently approached Marthinusen & Coutts to refurbish three mine winders for a new shaft being established.

Marthinusen & Coutts was contacted by Patrick de la Hunt, Impala Platinum Group’s mine winder engineer, to initially collect the winders to perform a detailed assessment in the company’s workshop. DRA was appointed as the project advisor to oversee the quality control and to carry out inspections. Rhys Castley, technical director of Technical Services winder system engineers, co-ordinated the DRA responsibilities.

The scope of work comprised major repairs to two AEG 3 850 kW mine winders and one Siemens
4 085 kW winder which were all previously owned by another mining company. Marthinusen & Coutts collected the three winders from the mine site and carried out the repair and refurbishment at its state-of-the-art facility in Cleveland, Johannesburg. The company will also assist the mine personnel with connecting and commissioning the equipment on site.

“These are massive mine winders,” Mike Chamberlain, Marthinusen & Coutts’ marketing executive, explained. “The Siemens unit is 4 metres in diameter and the AEG winders slightly smaller with 3.5 metre diameters. All three units were extremely complex to assess and it was a challenge to manufacture all the new spares and replacement parts required. There were literally thousands of different parts, which called for a great deal of attention to detail and specialist reverse engineering. It has also been a major task to document and control the status of all these parts.”

Repair work on the AEG winders includes restoration of the field frames, field and interpole coil replacement, damper bar replacements and reinsulation, as well as gang connector and field pole connector replacements. The armatures on both winders were also completely rewound.

“The armature core laminations on the Siemens 4 085 kW were damaged,” Chamberlain adds. However, the original armature core laminations on this winder were manufactured using an unconventional spiral segmentation method by machinery that is not available in South Africa. This method of lamination stamping meant that no two segments were the same and prompted some innovative ‘out of the box’ thinking from our engineering team, as well as input from our lamination supplier.” Chamberlain says that by refurbishing the mine winder motors instead of purchasing new motors, Marthinusen & Coutts’ motor could save the customers up to 70% of a new mine winder cost, plus the lead time for completion of the project can be substantially reduced.

Marthinusen & Coutts, a manufacturer and repairer of electric motors and components, has been in operation since 1954 and is the leading repairer of high-voltage motors in the southern hemisphere. The company also manufactures motors under licence for some international OEM’s and has more than 300 of its own designs. It has its own design department and has invested in critical equipment such as “full load” test facilities and crucial testing equipment that enable the Marthinusen & Coutts team to manufacture and repair motors with excellent results.

WINDER MOTOR REPAIRS FOR IMPALA WINDER PIC 01 : By refurbishing the mine winder motors instead of purchasing new motors, Marthinusen & Coutts’ motor could save the customers up to 70% of a new mine winder cost.