February 2014
MODERN MINING
19
COVER STORY
are tested to near destruction. “Very few com-
panies do type testing because it is extremely
expensive – it can easily cost R1,5 million to
test a new transformer model,” says Roets. “It
is also very time consuming, with the process
taking between three and six months. However,
we believe it is essential as it gives our custom-
ers the assurance that the product they have
bought will perform exactly as we say.”
Roets also points out that Kopex Africa is
audited every six months by SABS to ensure
that its flameproofing meets the relevant stan-
dards and adds that the company’s major
clients – Sasol Mining, BHP Billiton, Exxaro
and Anglo Coal, among others – also regularly
audit the company.
One of the big selling points of the Kopex
transformer range is the energy efficiency the
units offer. “We have achieved major improve-
ments over the past 20 years or so, with
efficiencies increasing from around 85 to 88 %
to 95 to 98 % today,” observes Roets. “Our
belief is that no other manufacturer can offer the
levels of efficiency our transformers achieve.
If you ask me how we have attained efficien-
cies this high, it is basically due to the years of
experience we have in the repair, design and
manufacture of transformers and our policy of
continuously improving our designs based on
this experience.”
Elaborating, Roets also points to the qual-
ity of construction. Cores are manufactured
from special, individually insulated plates of
sheet metal to stringent standards while the
windings consist of high-quality insulated
copper conductors. The coil construction is
separated by segments for cooling and sup-
ported by insulating spacers. The MV and LV
coils are impregnated with a silicone resin to
ensure a solid construction with high moisture
resistance. The transformers are all designed
and manufactured according to the IEC
(International Electro-technical Standard) 76,
which applies in Europe and the UK.
Apart from manufacturing new machines,
Kopex Africa also offers a full reconditioning
service which can bring aged machines to an
‘as new’ condition. Refurbishment currently
accounts for around 15 % of the company’s
business but there are plans in place to grow
this figure to 30 %.
On the subject of innovation, Roets says
Kopex Africa is well advanced with a proj-
ect to develop a new line of nitrogen-cooled
transformers with the delivery of the first three
units anticipated in June this year. “We’re
working closely with one of our customers on
this project,” explains Roets. “The benefits of
using nitrogen are that it is a more efficient
cooling medium than air and – being an inert
gas – the need for flameproofing is obviated,
thus allowing savings on weight and size. This
product definitely has the potential to revolu-
tionise the industry.”
The company is also looking at the possibility
of moving into the oil-cooled transformer busi-
ness. “We already supply transformers of this
type to customers but we have to outsource the
manufacture to sub-contractors,” says Roets.
“Although no final decision has been taken,
there is every possibility that we will buy a
company that makes oil transformers in order
to give us a foothold in this market.”
Looking ahead, Roets says that Kopex Africa
is currently nearing full capacity at its premises
in Apex Industrial Park in Benoni, where the
total property area is 15 000 m
2
. “If we want
to continue to grow we need to address this
issue,” he states. “One solution would be to buy
a new property but it is difficult to find suitable
premises in this area, particularly given the fact
that we need a high-capacity electrical sup-
ply because of the tests we have to undertake
on our products. The search for a property is
ongoing but if we are unable to secure suitable
premises we could look at moving the steel fab-
rication side of our business elsewhere, which
would allow the present factory – which has a
floor area of 5 000 m
2
– to be dedicated to final
manufacture and assembly, which is a more
high-tech process involving complex tasks such
as coil and panel winding.
“One way or another, we will resolve the
problem within the next few months. Putting
it in perspective, I think we’re fortunate that
the main challenge facing us is not selling our
products but ensuring that we have the capac-
ity to meet growing demand. Not many other
companies can say this in the present economic
climate!”
A Kopex worker puts the
finishing touches to a
dry type non-flameproof
transformer.
