installed into the stator of a machine much
The process begins with
more easily.
an initial assessment of the
components due for repair and
Maintaining the quality of every coil is
is followed by the design stage,
a continuous process that is applied to
which involves using the latest
all aspects of the production process,
3D CAD packages to produce a
including checks on all of the raw materials
series of manufacturing drawings
used in the manufacturing process. If there
for the coil shop. Precision and
are any perceived changes in the materials
accuracy of the drawings, coupled with
used in the insulation system, then a
the latest insulation technology allows
sample coil can be subjected, by customer
for improvements in coil design to be
request only, to voltage endurance testing
achieved.
Sulzer is the leading worldwide,
independent service provider for
large rotating equipment. With
technically advanced and innovative
service and maintenance support
solutions, Sulzer provides a turnkey
service that provides its customers
with the peace of mind to focus on
their core operations.
www.sulzer.com
in order to prove the insulation properties
and reliability are unchanged. Suppliers
have been known to change specifications
of their materials without providing such
information to the end users and so
periodic sampling is also conducted to
ensure the overall quality of the finished
product is maintained.
Precision and accuracy improve
performance
The use of B-stage resin rich coils is
predominant in the rewinding of larger
machines but this method also delivers
benefits for smaller machines. The
construction of the B-stage coils allows
the resin to flow in the end of the winding
and bond the layers of insulating tape to
produce a more homogenous insulation
and sealing of the winding. In most cases,
the use of modern insulating materials
will improve both the dielectric and
thermal performance when compared to
those used by the OEM during original
manufacture.
Quality starts with the raw
materials and Sulzer purchases
continuously cast copper rod and
uses its own in-house rolling and
annealing process, combined with
automatic shaping machines and
computer controlled heated
presses. The entire process can
operate 24 hours per day to deliver
consistently high quality coils with
very short delivery times. The coils
can then be dispatched from its
high-voltage coil shop, via freight
service, to any location worldwide
for delivery to site, ready for
installation.
By using the latest CAD software, the
bars or coils can be precisely designed
to ensure an exact fit in the stator
can be required to pass a 400 hour voltage
endurance test to provide evidence to
support their build quality.
slot, making the installation process
Modern insulation technology allows for
more efficient. Comprehensive testing
thinner layers that can withstand greater
techniques guarantee the reliability of the
dielectric stress and higher temperatures,
new coils, which is especially important
also allowing more space for copper within
for coils being used in marine, nuclear
the same slot area.
and hydro generators, where the coils
Is sue 21 PECM
5