When Marthinusen & Coutts’ longstanding customer, PPC called on the company to investigate the cause of smoke emitting from a 4000 hp, 11000 V, 163 A, 500 rpm Hitachi mill motor at its Hercules cement factory in Pretoria, the company visited the site and recommended that the motor be removed to its Cleveland repair facility for a full evaluation. PPC agreed and also asked this leading repairer of rotating electrical machinery to supervise the removal, loading and transport of the unit.

“The motor was exceptionally large and difficult to manoeuvre, however we were ready to assist with this special request from our customer to remove the motor,” Craig Megannon, Marthinusen & Coutts general manager, says. “The removal exercise involved hiring a 140 ton crane and an 80 ton low bed truck that was 4 metres wide, to accommodate this massive motor, complete with a traffic escort from Pretoria to Cleveland.”

Owing to its size and the technical risks associated with moving the motor, Megannon spent extensive time at the PPC site assisting with its removal and loading. Once at the Cleveland facility, the Marthinusen & Coutts team found that the motor’s rotor core had rubbed against the stator core, damaging the insulation of the rotor and stator windings and the interlamination insulation.

“Our assessment of the complete unit involved high-level testing of the cores and windings,” Megannon says. “These extensive tests found that, although the windings were still good electrically, both cores had been badly damaged and needed to be reinsulated and restacked. We will also send a team to the factory site to assist with installation and commissioning.”

The project was managed on behalf of PPC by Albert Fivaz, PPC Hercules engineering manager, and his team with assistance from Kobus Odendal, PPC group senior electrical engineer.

Marthinusen & Coutts, part of the Actom Group, is the leader in the repair and maintenance of rotating electrical assets throughout Africa. The company also manufactures motors under licence for some international OEM’s and has more than 300 of its own designs. The company 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 industry leading results.

PPC 4000 HP HITACHI PIC 01 : The 4000 hp 11000 V, 163 A, 500 rpm Hitachi mill motor from PPC's Hercules cement factory undergoing repair work at Marthinusen & Coutts' facility.