SPARKS October_2016

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SPARKS
ELECTRICAL NEWS OCTOBER 2016
CONTRACTORS’ CORNER
16
MILL MOTORS REPAIRED CHOP-CHOP
MARTHINUSEN & Coutts, a division of Actom, recently repaired
two large mill motors for leading uranium producer, Rössing Uranium
in Namibia.
Marthinusen & Coutts’ field service team was requested by Ross-
ing to inspect two brush mill motors on site. The team found that
the starting cage winding on one of the motors had moved and
rubbed against the stator winding, while an insulation test conduct-
ed on the second motor indicated that the stator winding was down
to earth. This necessitated having both motors repaired at Marthi-
nusen & Coutts’ facility in Cleveland. As no spare motor would be
available to the mine in the event of a further breakdown while the
two spare motors were being attended to by Marthinusen & Coutts
in Johannesburg, the first of the two 1 586 kW 3 300 V, 187.5 rpm,
brush motors to be repaired was treated with the greatest urgency.
Craig Megannon, Marthinusen & Coutts’
general manager says the repairs carried
out on the two motors consisted of rewind-
ing the stators incorporating use of a resin-
rich winding system, overhaul of the rotors
and complete replacement of the rotors’
electronic diode and synchronising hub.
Repair of the second motor was com-
pleted at the end of March. In addition to
the stator rewind with resin-rich windings,
the rotor was overhauled and the quad-
rants on a damaged damper winding of
the rotor were replaced.
Enquiries: +27 11 607 1700
Alpheus Mtshali, from Marthinusen & Coutts, is pictured
with the 1 586 kW 187.5 rpm, 3 300 V, 278 A stator.
The new Makita EK8100WS 405 mm indus-
trial power cutter is a valuable addition to in-
dustries such as construction, road building,
civil engineering, emergency services and other ap-
plications where there is a need to cut precisely and
effectively through concrete, stone, asphalt, steel
and other building materials. With the possibility of
power outages and load shedding always present,
utilising this petrol model makes perfect sense, as
work can continue unhindered.
The EK8100WS power cutter has been de-
signed for continuous heavy duty use. It is per-
fectly balanced and weighs only 10.6 kg. The
power cutter is powered by a 81 cc engine and
features a five-stage, foam-paper-nylon system
that uses advanced directional air flow to provide
clean air for a better saw performance.
It is easy to change the cutting arm position
from centre position to flush (outboard) position,
allowing for cuts that are directly adjacent to curb
edges, walls or directly above the ground. The on-
off-choke operating switch is located on one sin-
gle lever for added operator convenience.
An improved decompression valve and meter-
ing spring provides for precise fuel regulation, en-
hanced by a microchip controlled carburettor en-
gineered to compensate engine timing according
to work load. The ignition coil with start support
function, stores electrical energy with each pull
for a more efficient and easier start up.
Operator comfort is taken care of by utilising
four vibration-absorbing rubber engine mounts
as well as two mass-dampening systems that
deliver reduced vibration. The improved exhaust
has emissions are achieved with the Scavenging
Losses Rejection (SLR) muffler which recyles un-
burned fuel vapour and improves fuel consump-
tion by up to 15%. The Makita EK8100WS is sup-
plied with an abrasive wheel for cutting stone.
For further information or your nearest Makita
dealer, visit or
Enquiries: +27 11 878 2600
Petrol power cutter
takes the rough with
the smooth