VPI HIGH VOLTAGE - Von Roll

VPI system
for high voltage motors

Introduction
Von Roll is strongly committed to developing materials and processes used in
insulating state-of-the-art electrical high-voltage motors as well as small generators
with equivalent design. We are aware of our customers’ continuously increasing
demand for higher performance and reliability together with low manufacturing
costs.
Von Roll provides a wide range of process equipment and materials to fi t the
exact requirements of high-voltage motors using both resin-rich (RR) or vacuum
pressure impregnation (VPI) technologies.
Insulation materials for high voltage motors
Many different materials are used in constructing a high-voltage coil or bar:
WINDING WIRE (A)
CONDUCTOR INSULATION (B)
STACK CONSOLIDATION (C)
MAIN WALL INSULATION : MICA TAPE (D) + VPI RESIN (H)
CONDUCTIVE PAINT OR TAPE (F)
STRESS GRADING PAINT OR TAPE (F)
FINISHING OR SEALING TAPES (E)
BRACING MATERIALS (G)
SLOT WEDGING MATERIALS (I)
Customers enjoy the following advantages:
• Single source for all components
• Proven compatibility for system components
• Testing at Von Roll for both components and systems
• Single source for technical support
In this document we propose a variety of insulating materials and process
equipment for large generators. The selection is by no means exhaustive. Please
do not hesitate to contact our technicians for further details.

Conductors
For conductors of high voltage coils, Von Roll offers a complete range of
products:
• Covered wires with impregnated Glass yarn (Silix ® )
• Covered wires with mixed Glass/Polyester yarn (Daglas),
impregnated or not
• Samicafilm-tape covered wires
Samicafilm tape covering on bare or enamelled wires is the preferred conductor
insulation for stator coils due to its large advantages:
• Better corona resistance
• Reduced insulation thickness
• Softer copper enabling an easier workability
• Greater manufacturing flexibility
Samicafilm products are based on Von Roll Samica ® mica paper impregnated
with modified epoxy resin, reinforced with one or two polyester film backings and
with or without adhesive coating.
Product name
Rated voltage (KV)
13.8
Thickness
(mm)
Weight
(gr/m 2 )
Mica
(gr/m 2 )
Composition
Adhesive
Samicafilm ® F60+ ■ ■ ■ 0.06 76 30 Film / Mica yes
Samicafilm ® F75 ■ ■ ■ 0.075 101 50 Film / Mica no
Samicafilm ® 315.14 ■ ■ ■ 0.09 131 75 Film / Mica no
Samicafilm ® 315.15-11 ■ ■ ■ 0.09 135 75 Film / Mica yes
Samicafilm ® F2 90 ■ ■ ■ 0.09 124 65 Film / Mica / Film no
Samicafilm ® F2 90+ ■ ■ ■ 0.09 126 65 Film / Mica / Film yes
Samicafilm ® tapes are applied butt-lapped or overlapped to the conductor.
Von Roll supplies both tape and taped conductors to its customers.
Product name
On bare wire
Insulation design
Rated voltage (KV)
Thickness
13.8 unpressed pressed
Adhesive
Samicafilm ® 315.14 2 butt lapped layers ■ 0.36 0.30 no
Samicafilm ® 315.15-11 2 butt lapped layers ■ 0.36 0.30 yes
Samicafilm ® F2 90 3 butt lapped layers ■ ■ 0.54 0.43 no
Samicafilm ® F2 90+ 3 butt lapped layers ■ ■ 0.54 0.43 yes
On enamelled copper grade 2
Samicafilm ® F2 90 1 1/2 lapped layer ■ ■ ■ 0.50 0.43 no
Samicafilm ® F2 90+ 1 1/2 lapped layer ■ ■ ■ 0.50 0.43 yes

The following products in the classical range are used for high-voltage motors.
Product name
Rated voltage (kV)
13.8
Dimensions
Description
Silix ® on bare wire ■ on request Glass lapped wire with or without B-stage overcoat
Silix ® on enamelled wire ■ ■ ■ on request
Daglas on bare wire ■ on request Daglas lapped wire with or without B-stage overcoat
Daglas on enamelled wire ■ ■ ■ on request
VS 220 / VS 240 ■ ■ ■ on request
Polyamide-imide or Polyimide enamelled flat copper
wire insulated with impregnated glass yarns
Yarn coverings are impregnated with varnishes based on epoxy, polyester-imide,
polyamide-imide, silicone or polyimide resins, depending on the thermal class
required. Special “B-stage” varnishes are also available for the conductor stack
consolidation.
Von Roll offers a wide variety of dimensions to meet
customer needs.

Coil production
Von Roll is heavily involved in every aspect of high-voltage technology, including
process equipment. For high-voltage motors Von Roll M Tec has developed a line
of coil-producing machines that use flat-coil technology. This line of equipment
includes the following units:
• Wire dispensing and preparation
• Loop winding
• Taping
• Coil forming
Coil forming machine produced by Vincent Industries
Stack consolidation
Depending on the system, stack consolidation may be included.
Employing Samicafilm with a hot-melt adhesive or glass lapped wires in B-stage
enables rapid consolidation of conductor stacks without the need for additional
consolidation products.
When using Samicafilm without hot-melt adhesive or non-B-stage wires, traditional
hot-press consolidation is preferred. This system can be achieved by overlapping
the stack with Thermopreg 251.78.
Von Roll standard materials for stack consolidation:
Product name
Form
Rated voltage (KV)
13.8
Thickness
mm
Description
Thermopreg 251.78 Tape ■ ■ ■ 0.1 Impregnated glass cloth
Glass fleece 101.74-07 Tape ■ ■ ■ 0.56 Non impregnated polyester fleece
Glasoflex 261.10-03 Tape ■ ■ ■ 0.5
Damival 15182 / 9030 Resin ■ ■ ■
Impregnated glass fleece with high
resin content
Solventless 2 component epoxy
resin

Main wall insulation
Von Roll recognizes the problems associated with improving the quality and cost
effectiveness of high-voltage insulation. With Samicapor ® , Von Roll has developed
a range of vacuum pressure impregnation (VPI) mica tapes that satisfy the
requirements of main wall and end-winding insulation, namely:
• High dielectric strength
• Corona discharge resistance
• Fast and easy impregnation
• Resin retention without draining
• Smooth application without creasing
• Both manual and fast-running machine application
• Full compatibility with predefined resin systems
Product name
Rated voltage (KV)
13.8
Thickness
(mm)
Weight
(gr/m 2 )
Mica
(gr/m 2 )
Composition
Resin compatibility and thermal class
Non accelerated
epoxyanhydride
Accelerated
Epoxy VPI
systems
Polyesterimide
Samicabond
System
Samicapor ®
366.55-10
Samicapor ®
366.58
Samicapor ®
366.58-18
Samicapor ®
366.58-20
Samicapor ®
374.04
Samicapor ®
374.15
Samicapor ® P
315.33
Samicapor ® P
315.45
■ ■ ■ 0.15 200 160 Glass / Mica F
■ ■ ■ 0.15 195 160 Glass / Mica F H
■ ■ ■ 0.15 213 180 Glass / Mica F H
■ ■ ■ 0.17 224 180 Glass / Mica F H
■ 0.18 241 160
■ 0.18 241 160
Glass / Mica /
Fleece
Glass / Mica /
Fleece
■ ■ 0.14 214 160 PET / Mica F
■ ■ 0.14 214 160 PET / Mica F H
F
F
F
Von Roll has a total commitment to mica
Careful and optimum application of Samicapor ® tapes can be obtained using
Von Roll M Tec taping machines.
Taping machine by our partner Micamation

Corona protection
All high-voltage machines require electrical stress control measures.
Von Roll has developed a number of products under the trade name CoronaShield ®
namely:
• Conductive tapes
• Semi-conductive tapes
• Conductive mastics
• Conductive varnishes
• Conductive tapes with Nomex ® technology
These tapes can all be used for:
• Internal corona protection (IGS) - in the conductor stack
• External corona protection (AGS) - within the slot
• End corona protection (EGS) - at the slot end
Product name
Form
Rated voltage (KV)
6 to 13.8 >13.8
Thickness
(mm)
Resistivity
(Ohm Sq)
Description
Conductive tape
215.51
Conductive tape
215.55
CoronaShield ®
250 N 125
Semi-Conductive tape
217.01/217.21
Semi-Conductive tape
217.31
Tape ■ ■ 0.1 200-400
Tape ■ ■ 0.085 200-400
Tape ■ ■ 0.125 250
Tape ■ ■ 0.22 Variable
Tape ■ ■ 0.25 Variable
Based on impregnated non woven
polyester fleece. Not compatible with
Epoxy Anhydrid VPI resin
Based on impregnated non woven
polyester fleece.
Non impregnated conductive tape with
Nomex technology
B-Stage semi conductive tape with
different characteristics
Fully cured silicone carbide filled resin tape
impregnated in a non woven fabric.
Conductive and semi conductive tapes

Finishing tapes
The mica tapes used in main wall and overhang insulation contain materials that
can easily be damaged and need to be protected against:
• Moisture
• Mechanical load
• Damage
• Resin flow
• Atmospheric pollutants
Product name
Form
Rated voltage (KV)
< 6 6 to 13.8 > 13.8
Thickness
(mm)
Description
Epoflex ® 324.03 Tape ■ ■ ■ 0.09
Polyester glass fabric with a Polyester film and
reduced binder quantity
Winding and bracing of machines
The simplicity of the winding process for machines with «dry» coils is a recognized
benefit of VPI technology. Substantial advantages obtain during the end-winding
bracing and support process. Von Roll has developed a range of ropes, cords,
and sleeves for «surge ring» intercoil lacing
The main benefits of these products are:
• Class C (glass) and F (polyester) applications
• Compressibility and resilience
• Glass or polyester yarn on the outside
• Wide range of dimensions
• Un-impregnated for use with VPI; no further processing
• Impregnated polyester shrink cord for use with RR technologies
Product name
Form
Rated voltage (KV)
< 6 6 to 13.8 > 13.8
Thickness
(mm)
Description
Isocord ® 151.10 Cord ■ ■ ■ From 1.8 to 50
Isocord ® 151.12 Cord ■ ■ ■ From 1.5 to 60
Braided silane E glass yarn outside
with staple glass filler
Braided polyester garn outside
with staple glass filler
Glass or glass polyester cords

Composite materials for high-voltage motors
Von Roll offers a variety of composite materials that can be delivered as
wedges, sheets, machined parts, or special components that are used
in different sections of a high-voltage rotating machine. The following are
just a selection. Please ask our specialists about additional products.
Product name
Form
Rated voltage (KV)
< 6 6 to 13.8 > 13.8
Stator Slot Insulation
Magnetic stator SW
Rotor Slot Wedges
Commutator
Vetronite ® G-11
Delmat ® Epoxy
68660
Delmat ® Polyester
68420
Commutator
Samicanite 41120
Machined component
or full size sheet
Machined component
or full size sheet
Machined component
or full size sheet
Machined component
or full size sheet
■ ■ ■ ■ ■
■ ■ ■ ■ ■
■ ■ ■ ■
■ ■ ■ ■
Mica Rings Part on design ■ ■ ■ ■
Vetroferrite ® 432.20 /
432.21
Machined component ■ ■ ■ ■
Von Roll makes composite parts to customer specifications and design

VPI resins
There are several families of resins with excellent electrical characteristics when
cured. The factors influencing the final choice of resin used are much more
complex. Important considerations are linked to the characteristics of the design
of the machines, the insulating system choice, the taping and VPI processes but
also on more basic parameters. Important criteria include:
• Resin thermal class
• Tank stability
• Storage conditions (cooled or ambient temperature)
• Moisture sensitivity
• VOC (Volatile Organic Compound)
• Impregnating Temperature
• Necessity of rotating curing
• Curing Time
• Total processing time
• Compatibility with mica tapes and the other materials
• Rated voltage
• Dielectrical properties
• Mechanical properties
• Thermal conductivity
• Continuous and maximum peak operating temperature
Von Roll offers a variety of high performance resins:
Product
Type
Thermal
class
Rated voltage (KV)
< 6.6 6.6 to 15 > 15
Impreg.
temp.
Curing
process
Description
Damisol ® 3340
Polyesterimide
(Samicabond)
H ■ 23°C
8h at
150°C
Highly reactive, yet highly stable
room temperature impregnating
resin. Good results on static curing.
Damisol ® 3032
Polyesterimide
(Samicabond)
H ■ 23°C
8h at
140°C
Highly reactive, yet highly stable
room temperature impregnating
resin. Good results on static curing.
Damisol ® 3308
Polyesterimide
(Samicabond)
H ■ ■ 23°C
8h at
140°C
Highly reactive, yet highly stable
room temperature impregnating
resin. Good results on static curing.
Damisol ® 3309
Polyesterimide
(Samicabond)
H ■ ■ 23°C
8h at
150°C
Highly reactive, yet highly stable
room temperature impregnating
resin. Good results on static curing.
Damisol ® 3313
Polyester/
Epoxy
H ■ ■ 23°C
8h at
150°C
High mechanical properties. Good
results on static curing
Damisol ® 3413
Epoxy/
Anhydride 2K
F ■ ■ 23°C
10h at
150°C
Low viscosity 2 K accelerated
epoxy resin with outstanding
mechanical properties.
Permafil ®
74038
Epoxy 1K H ■ ■
23 to
60°C
8h at
160°C
1K epoxy resin without diluent. Very
low organic emission (VOC

Drying and impregnation
The principles of air drying, controlled rate impregnation, pressuring, and curing of
resin are well understood by VPI process users and potential users.
Through M Tec, Von Roll offers VPI systems tailored to meet the needs of all
sectors of the rotating machine industry.
For new equipment or upgrading existing plants, M Tec ensures state-of-the-art
VPI technology.
Instrumentation for measuring capacitance, essential for in-line quality control of
impregnation, is built into the systems.
Impregnation unit by our partner Meier Prozesstechnik
Finishing coating
The Damicoat ® range of finishing and overcoat varnishes includes air-drying and
oven- curing solutions. They are all single-component for easy processing by
spray, brush, and even dipping and dip-rolling processes
Product Chemistry Colour
Rated voltage (KV)
< 6 6 to 15 15 to 22
Thermal
Class
Drying
Time
Description
Damicoat ®
2404
Damicoat ®
2407
Alky phenol N/RB/G ■ ■ F 15 - 20h
Alkyd
modified
RB ■ ■ F/H 1 - 2h
Highly chemical resistant overcoat
varnish.
High temperature resistant overcoat
varnish, used up to class H of high
voltage and traction machines.

Von Roll Switzerland Ltd. • CH-4226 BREITENBACH
www.vonroll.com
All information in this document is subject to the product liability clause as published in the Website www.vonroll.com under legal information.