Brochure

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Even stator coil spacing maintains the electrical and mechanical integrity of the machine.
Insulation
Mica composite, epoxy resin and
vacuum-pressure impregnation
(VPI) provide a robust and reliable
insulation system.
The advanced insulation system
on all large machines will typically
reward you with years of reliable
operation. GE’s insulation system is
designed to minimize the eect of
localized electrical stress and reduce
the eects of partial discharge
while increasing machine life and
reliability. Components are selected
to ensure reliability of the system as
a whole.
The insulation system can meet
applicable standards. All wound
stators undergo global vacuum-
pressure impregnation (VPI)
treatment. Curing binds the stator
components into a solid and rigid
structure with excellent dielectric
strength, dimensional stability and
mechanical strength. It also increases
the resistance of the winding to
thermal shock, moisture and other
contaminants.
The binding agent used is GE’s third
generation epoxy resin, selected and
tested to IEEE-1776 for chemical
compatibility, thermal/dimensional
stability, and electrical properties.
The coil turns in the slot section are
bonded using heat and pressure to
achieve dimensional accuracy of the
nished coil.
The mica composite insulation is designed for
uniform ground insulation dielectric strength.
Above 6000 volts, a semi-conducting
paint is applied to the slot portion and
graded beyond the core to provide
corona protection.
A protective armor of heavy
glass tape is used for protection
against mechanical shock and
abrasion.
Copper
Conductor
Ground Wall
Insulation
Turn
Insulation
Strand
Insulation
Coil Insulation
Once assembled, the coils are inserted
into the stator slots and the end
connections are brazed and taped.
GE’s coil lock bracing system supports
the coils and makes the entire
structure more rigid.