Page 18 - SPARKS APRIL 2013 1-28 LOW RES

sparks
ELECTRICAL NEWS april 2013
18 motor control centres and motor protection
ACTOM Electrical Machines, a leading
South African designer, manufacturer and
supplier of electric motors, has completed
manufacture of all the customised low
voltage motors required for the air-cooled
condenser (ACC) units at Eskom’s newMe-
dupi and Kusile coal-fired power stations.
The company was awarded the ACC
units LVmotors contract for Kusile power
station near Delmas in Mpumalanga in
TwomembersofACTOMElectricalMachines’factorystaffareseenheredoingfinishing
touchestooneamonga largebatchof250kWsquirrelcage inductionmotorsawaiting
deliverytoSPXfor installation inair-cooledcondensersforKusilepowerstation.
LV motors contracts for Medupi and
Kusile completed
August 2009 by Johannesburg-based SPX
(DB Thermal), the ACC subcontractor to
Alstom Power, the main contractor for the
turbines of the new power station. This fol-
lowed the award in November 2008 of the
ACC units LVmotors contract for Medupi
power station near Lephalale in Limpopo
Province by GEA Aircooled System, the
ACC subcontractor to Alstom Power in
that instance.
The Medupi and Kusile ACCmotors con-
tracts together are worth close to
R100-million.
The contract, for design, manufacture
and supply of a total of 384 x 250kW four-
pole squirrel cage inductionmotors, along
with soft-starters, for the ACC units at Kusile
was completed well ahead of schedule,
while the Medupi contract, comprising a
total of 384 x 225kW four-pole squirrel cage
inductionmotors, has been completed on
schedule.
Tony Teixeira, ACTOM Electrical Machines’
general manager, says,“In tackling the
Kusile contract we benefitted greatly from
the experience we gained on the Medupi
contract, but it involved some unique chal-
lenges of its own.”
The earlier contract involved designing
and developingmotors that incorporated
additional equipment without compromis-
ing their efficiency. To ensure that this was
achieved the company first produced a
prototype motor, which it test ran to ensure
that the contract’s stringent performance
specifications were met before it went
ahead with production of the final product.
“The motors for Kusile follow the same
design concept as developed for Medupi’s
ACC units. However the soft-starters
required for the Kusile motors necessitated
a similar preliminary test exercise, for which
we developed a simulation process to test
the soft starter-motor-load combination
to ensure that it worked at optimum ef-
ficiency,”Teixeira explains.
“We designed and assembled a special
itemof equipment to simulate the actual
site conditions. These prototype tests were
witnessed and approved by SPX, Alstom
and Eskom.”
Enquiries: (011) 899-1081
Wesley Doorsamy (above) and Professor Willie Cronje
from the School of Electrical and Information Engineer-
ing at Wits University represented WITS at the recent IEEE
International Conference on Industrial Technology (ICIT
2013) held in Cape Town. They presented a paper titled,
‘Multiple fault diagnosis on a synchronous two pole
generator using shaft and flux probe signals’. The paper
deliberates ongoing work conducted on the develop-
ment of a system that utilises shaft voltage analysis as a
method of condition monitoring. The IEEE International
Conference on Industrial Technology (ICIT 2013), a major
annual conference of the IEEE Industrial Electronics So-
ciety, was held in Cape Town at the end of February and
included 322 presentations of high quality papers over 10
technical tracks.
Enquiries: (011) 717-7012
Wits EIE at ICIT
conference