Project Vicky

Gold Mining – 2018


As part of the demand side management strategy the mine had to reconcile the available compressors vs. the real demand for compressed air. A decision was made to run bigger more efficient units and to have smaller less efficient units on a standby basis. A 10.3MW compressor was selected and had to be brought back to the highest efficiency possible. The compressor was built in 1977 and was driven by a 40-year-old Parsons Peebles electric motor with previous repairs. The compressor was overhauled and the motor had to be replaced with the most recent technology which could yield additional energy savings by means of an increased efficiency level.


The customer wanted a new very efficient motor and the motor had to fit exactly in the place of the old motor without any modifications. The Motor is started directly on line thru a voltage reducing “auto” transformer


WEG designed a water-cooled motor with the latest technology available in the market.


The motor fitted perfectly, showcasing WEG’s ability to manufacture “Drop-in replacement” machines.

Due to a weaker supply network and troublesome voltages during the starting conditions, the rotor bar construction had to be revised during the commissioning process.

After the final commissioning the motor ran successfully with a 300kW demand reduction when comparing to the original motor yielding energy savings of approximately R2M per annum.


Much higher savings can be derived by using a WEG CFW 500 VSD in combination with a WEG motors for fan applications.


  • MGW 900 water cooled motor
  • 10,3MW 6 poles and 6600V
  • Motor efficiency of 97.4%