Transformer-dry-type-handbook1

Dry Type Transformer Electronic, Power Supply or Distribution Applications Oil Filled Transformer Medium & Large Power Applications Additional informatin found in TGC’s Oil Filled

Relentlessly Responsive

DRY TYPE TRANSFORMER INSULATION HANDBOOK

ISO 9001: 2008 CERTIFIED FABRICATOR OF THERMAL INSULATION MATERIALS

THE GUND COMPANY

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Table of Contents I Introduction to the Gund Company Preface 4

Our Locations 5

Primary Customer Segments 6

Transformer Insulation Components Overview 7-8 II Transformer Coil Insulation Components Coil Insulation Overview

Winding Bobbins 11

Insulating Core Tubes 12

Conductor Insulation 13

Layer Insulation 14

Layer Insulation Tape 15

Intra-Coil Phase Barriers 16

Inter-Coil Phase Barriers 17

Winding Combs 18

Coil Shims 19

Air Duct (Axial) Spacer Sticks

III.Coil Support & Superstructure Components Coil Supports 22

Insulating Nuts & Bolts 23-27 Phase Barriers 28

Insulating Angles & Channels 29

Stand-off Insulators

IV.Tap Changer Components Tap Changer Components 32

V Material Data Sheets Laminate Sheet, Rod, & Tubing Glass Epoxy Laminate Sheet & Tubes (NEMA Grades G-10/FR4 & G-11) 34-35 Glass Polyester Molded Insulation Materials Glass Polyester Molded Sheets (NEMA Grades GPO-1, GPO-2, GPO-3) 36-39 Glass Polyester Molded Sheet, NEMA Grade N180

Glass Polyester Molded Sheet, DuraNohl™ N220 41

Glass Polyester Laminate Sheet, 220°C Grade SG-200 42

Glass Polyester Laminate Sheet, 220°C Grade HST-II 43

Glass Polyester Pultruded Angles & Channels 44-45

Glass Polyester Molded Stand-off Insulators 46-49

Glass Polyester Pultruded Shapes (Rods, Dogbones, & Squares) Fax (314) 423-9009

Nomex™ Insulating Materials

NomexTM Aramid Paper 51-53

NomexTM Paper Products 54

Other Flexible Transformer Insulation Materials

Quin-T Family of Products 55-60

PolyPro FR™, Flame Retardant Polypropylene 61

Other Transformer Insulation Materials

Glass Epoxy Filament Wound Tubing 62

VI Appendix

Dry Type Transformer Kitting Checklist 64-68 Winding Comb Order Sheet 69 Application Engineering 70 Contacting The Gund Company 71

Section I Introduction to The Gund Company

contain transformer insulation application information Section V contains the technical data

sheets for transformer insulation materials and Section VI, the final section, discusses Application

Engineering and contact information for The Gund Company

This handbook is intended for manufacturing engineers, repair specialists, field service technicians, purchasing agents, shop foremen, and everyone who may be involved in the

specification, selection, and use of electrical insulating materials for transformer equipment

The reader should be advised that this handbook does not represent a complete account of

The Gund Company’s products and services nor a complete record of all insulation materials

utilized in the many and varied transformer designs Instead, it is meant to be a collection of

technical information pertaining to the most commonly encountered insulation materials and

their application in transformers If a desired product or component cannot be found, please

contact us and we can discuss potential options

Please keep in mind that all information and data contained in this handbook is believed to

be reliable, but all recommendations or suggestions are made without guarantee Furthermore,

suggestions for use of material supplied shall not be construed as a recommendation or

inducement to violate any law or infringe on any patent

We hope that the product and application information along with the sample component drawings help involved individuals to make informed decisions The Gund Company welcomes

any comments, suggestions, or applications questions We sincerely appreciate the opportunity

to assist you in meeting your electrical insulation requirements

Our Locations

Cedar Lake, Indiana (Chicago)

• 30,000 Sq Foot Fabrication Facility

Milwaukee, Wisconson

• 50,000 Sq Foot Fabrication Facility

• 20,000 Sq Foot Molding Facility

Fergus, Ontario (Toronto)

• 55,000 Sq Foot Fabrication Facility

San Bernardino, California

• 20,000 Sq Foot Fabrication Facility Cedar Lake, IN (Chicago)

Mexico City, Mexico

St Louis, Missouri

• Corporate Headquarters

Winding kits including coil spacer sticks, coil wedges, step blocks, terminal strips, phase barriers, cable clamps, and bus supports Layer insulation options and PSA layer tapes

By focusing on understanding our customer’s specific application requirements, TGC has delivered solutions to customers around the world TGC exports to more than

32 countries including Japan, Korea, China, Austria, United

Power Supply

A natural extension of both the switchgear and transformer insulation business From Dry Type Transformer Components

to Chassis Liners and every insulator in between, TGC can provide kitting solutions

Switchgear Insulation

TGC is an integrated manufacturer of glass polyester laminates (GPO-3) with complete fabrication capability for phase barriers, terminal supports, bus bar supports, and cable clamps

Transformer Insulation Components Overview

The Gund Company manufactures insulating components for many types of electrical transformers including:

• Large Power Transformers

• Oil Filled Distribution Transformers

• Dry Type Distribution Transformers

• Dry Type Power Supply Transformers

• Electronic Transformers

Though transformers perform a similar role in the power distribution system regardless

of design, the various transformer insulation design parameters can be quite different For

example, an oil filled transformer used for outdoor power distribution applications requires

insulating components compatible with the dielectric fluid used in the transformer On the

other hand, a dry type transformer used for power distribution inside a building requires a

higher temperature insulation system typically rated for 180°C to 220°C While the design or

function of an insulating component may be similar in both oil filled and dry type transformers,

the material selection criteria can be completely different

The Gund Company has put together the Dry Type Transformer Insulation Handbook

to help serve as a reference tool for our customers involved in the manufacturing and repair

of transformer equipment We have attempted to gather information on the most common

insulation component applications as well as the most common insulating material alternatives

If we have not included a particular material or application of interest to you, please contact us

for a specific review of your requirements The Gund Company has also produced an Oil Filled

Transformer Insulation Handbook which may be requested by contacting The Gund Company

Over the years, The Gund Company has served as a partner for many of our customers interested in lowering the cost structure of their design By partnering with our customers,

we can review current insulation system designs in order to help identify areas for potential

cost reductions Many of our customers participate in our “Cost Reduction Initiative Program”

wherein we request design information, assembly drawings, and related information so that we

can make a proposal that may lower the cost of production

Whatever your transformer insulation requirement may be, The Gund Company has the material knowledge and technical capability to assist you in developing potential engineering

Dry Type Transformer

Electronic, Power Supply or

Distribution Applications

Oil Filled Transformer

Medium & Large Power

Applications

Additional informatin found in TGC’s Oil

Filled Transformer Insulation Handbook

Oil Filled Transformer

Distribution Applications

Additional informatin found in TGC’s Oil

Filled Transformer Insulation Handbook

Insulating Component

Conductor Insulation Layer Insulation Layer Insulation Tape Winding Comb Coil Wedges Air Duct (Axial) Spacer Sticks Phase Barrier

Coil Clamps Bus Bar Supports Winding Bobbins Insulating Nuts & Bolts Insulating Angles & Channels Stand-off Insulators

Conductor Insulation Layer Insulation Layer Insulation Tape Crossover Pad Insulation Core Insulation

Core Spacers Core Fastener Insulation Axial and Radial Spacers Punched Spacers Clamping Plates & Rings Lead Termination Insulation Lead & Cable Clamps Coil Supports – Step Blocks Insulating Nuts & Bolts Tap Changer Insulating Boards Lead & Cable Tubing

Tie Plate Bolt Insulation Layer Insulation Layer Insulation Tape Crossover Pad Insulation Phase Barriers

Insulating Angles & Channels Fuse & Terminal Boards Insulating Tubing

Common Materials

Slit Nomex Aramid Paper Coils Nomex™ Aramid Paper, Quin-T Glass Cloth Tape, TESA 4617 Glass Polyester Laminate, SG-200, N220 Glass Polyester Laminate, GPO-3 Glass Polyester Dogbone Rod Glass Polyester Laminate, GPO-3 Glass Polyester Laminate, GPO-3 Glass Polyester Laminate, GPO-3 Glass Epoxy Laminate, G10 / G11 Glass Epoxy Laminate

Glass Polyester Pultrusions Molded Glass Polyester Nomex™ & Creped Kraft Paper Diamond Epoxy Coated Kraft Glass Reinforced Polyester Tape Rag Paper Insulation – COPACO Glass Polyester Laminate, GPO-1 Glass Polyester Laminate, GPO-1 Glass Epoxy Laminate, G-10 Fabricated Pressboard Material Fabricated Pressboard Material Fabricated Pressboard Material, Laminated Wood Paper Phenolic Laminate, XXX

Paper Phenolic Laminate, XXX Fabricated Pressboard Material, Laminated Wood Glass Epoxy Laminate, G-10

Low Power Factor Paper Phenolic Paper Phenolic Laminate, XXX Glass Epoxy & Steel Assembly Diamond Coated Kraft Paper Glass Reinforced Polyester Tape Rag Paper Insulation – COPACO Glass Polyester Laminate, GPO-1 Glass Polyester Pultrusion, GPO-3 Glass Polyester Laminate, GPO-1, NEMA XXX Paper Phenolic Tubing, XXX

Section II Transformer Coil Insulation Components

Insulated Yoke Bolt

Adjustable Insulated Pressure Plate

Core

Cooling Duct Insulating Spacers

Insulating Pressure Collar

Low Voltage Winding

High Voltage Winding

Insulating Tubes

Insulated Core Bolt

Insulating Barrier Between Coils

Insulating Pressure Collar

Adjustable Insulating Pressure Plate

Transformer coils require a variety of insulation materials depending on the specific

design characteristics of the transformer, such as dry type or oil filled, temperature

rating, and application In general, coil insulation would include the different

insulations used between the core and the windings, between the windings

themselves, and around the coil itself The following pages will cover these insulation

applications including:

Core Insulation Layer Insulation Conductor Insulation

Winding Combs Spacer Sticks Pressure Collars

Air Duct (Axial) Spacers Lead Insulation Layer / Coil Tape

Pressure Plates Pressure Rings

Winding Bobbins

Description

Many dry type transformers for electronic and power

supply applications utilize winding bobbins in their design

Of course, almost all high volume electronic transformer

winding bobbins are molded from thermoset or

thermoplastic resins The Gund Company supplies

custom fabricated winding bobbins using thermoset

composites which offer excellent mechanical strength

and outstanding dielectric properties at elevated

temperatures Custom winding bobbins can be made in

quantities from a few to several thousand

Common shapes for custom winding bobbins include square, round, oblong, and rectangular

Most winding bobbins consist of an insulating tube bonded to a series of flanges made from

sheet material A bobbin may have multiple flanges to allow for the separation of phases

according to the transformer design

Materials

• Nomex™ Aramid Paper & Pressboard Material

• Glass Epoxy Laminate, NEMA Grade G-10/FR4

• Glass Epoxy Laminate, NEMA Grade G-11

• Glass Polyester Laminate, NEMA GPO-3

• Glass Polyester Laminate, Grade N220

Most transformer coils are wound around a mandrel The mandrel

often has an initial wrap of insulation material which can be as

simple as Nomex™ Aramid Paper taped around the mandrel or which

can be a filament wound tube

Historically, filament wound tubes were used as a common practice

for core tubes, but many companies evolved to using Nomex™

Aramid Paper for various reasons As the cost of Nomex™ has

increased over time, filament wound tubes are proving themselves

to be very cost effective for insulating core tubes

A filament wound core tube provides excellent mechanical strength with even a 0.030” wall

relative to Nomex™ Aramid Paper with a 0.060” wall Filament wound tubes do slide right on

the mandrel and can lower labor costs relative to the awkward process of taping 0.030” layers

on Nomex™ around a mandrel Also, filament wound tubes are extremely abrasion resistant

and can withstand the driving of the core shims to tighten the core / coil assembly Of course,

filament wound core tubes do need to be ordered with an advance lead-time of one to two

weeks and must be ordered to size whereas a Nomex™ core tube can be made and taped right

on the existing mandrel

Materials

• Nomex™ Aramid Paper

• Quin-T Family of Papers

• Filament Wound Glass Epoxy or Glass Polyester Tubing

Description

Most dry type transformers use a paper based insulation wrap over the conductor as a

secondary insulation in addition to the conductor’s primary varnish insulation Sometimes,

the Aramid paper insulation is wrapped around the bare conductor (with no varnish) as

the primary insulation The insulating paper material offers additional insulation protection

between the turns of the transformer coil while protecting the conductor from abrasion,

scratches, and cuts during the manufacturing process

The Gund Company custom slits insulating papers into coils for conductor insulation

applications Typical conductor insulation ranges in thickness from 001” to 003” and ranges

in width from 375” to 750” The Gund Company supplies coils on 3” ID or 10” ID coils with a

maximum O.D of 18”

For conductor leads that exit the winding, The Gund Company supplies insulating sleeving

and pressure sensitive tapes depending on the manufacturer’s design and insulation system

requirements

Materials

• Nomex™ Aramid Paper

• Quin-T Family of Insulating Materials

• Kapton Polyamide Film Tape

• Varflex Insulating Sleeving (for leads)

• Intertape Polymer Tape (for leads)

Conductor of a barrel wound transformer wrapped with Nomex™ Aramid Fibre Tape

Layer Insulation refers to the relatively thin (.005” - 020” typical) layers of flexible insulation

material used between the turns of conductor, most typically in bobbin wound coils Layer

insulation typically requires the use of pressure sensitive tape in order to help hold the layer

insulation in place These pressure sensitive tapes perform a largely mechanical role, but must

be compatible with the transformer’s insulation system

Top-Down view of a barrel wound transformer pointing out the Nomex™

Aramid Paper layer insulation

For dry type transformers, the most commonly used layer insulation material is Nomex™

Aramid Paper While Quin-T family of insulating papers has found application for dry

type transformer layer insulation, many companies have not approved Quin-T lower cost

alternatives Some dry type transformer designs also utilize a B-Stage glass cloth product For

additional information on various B-Stage glass cloth construction alternatives, please contact

The Gund Company

Insulating tape, used in conjunction with dry type transformer layer insulation typically, is

a glass cloth based tape with a rubber or silicone adhesive to reach the 220°C temperature

rating

Materials

• Nomex™ Aramid Paper

• Quin-T Family of Insulating Products

• B-Stage Epoxy Impregnated Glass Cloth

• Glass Cloth Based Rubber Adhesive PSA Tape

Layer Insulation Tape

Description

Most dry type transformers use a pressure sensitive tape for holding down the layers of

insulation as the coil is being wound In electronic transformers, pressure sensitive tape is

typically the layer insulation itself

Though not a complete representation of all electrical pressure sensitive tape in the

marketplace, the following tapes are commonly used for layer insulation tape applications

Dry Type Transformer Layer Insulation Tapes:

Designation Thickness Backing Material Reinforcement Adhesive

Intertape 4618 007” Glass Cloth Glass Cloth Silicone

Intertape 4617 007” Glass Cloth Glass Cloth Silicone

Intertape 4428 0022” Polyimide Film n/a Silicone

Intertape 4429 0035” Polyimide Film n/a Silicone

Please contact The Gund Company for a complete listing of pressure sensitive adhesive tapes

for electronic transformer applications Data sheets are available upon request for any tape

product

For applications between the primary and secondary winding, a flexible layer of

high-temperature glass polyester laminate such as Grade FHT or Grade N200F would be used in

thicknesses ranging from 0.030” to 0.093” Nomex™ Aramid Paper is also sometimes used by

layering up 0.030” material

Materials

• Nomex™ Aramid Paper

• High-Temperature, Flexible Glass Polyester Laminate, Grade N200F

• High-Temperature, Flexible Glass Polyester Laminate, Grade FHT

Top-down view of a transformer with the primary windings (1) insulated with N200F or FHT and the secondary windings (2) insulated with Nomex™

For applications between the coils of the transformer, Grade FHT or Grade N200F can be

wound into the outer layers of the coil on the side closest to the adjacent coil

Some applications for higher voltage transformers place the phase barriers outside the coil

winding between each coil These phase barriers are typically made from 0.125” or 0.187”

NEMA GPO-3

Materials

• Nomex™ Aramid Paper

• High-Temperature, Flexible Glass Polyester Laminate, Grade N200F

• High-Temperature, Flexible Glass Polyester Laminate, Grade FHT

• Glass Polyester Laminate, NEMA Grade GPO-3

Phase barriers made of GPO-3 between the coils of a disk wound transformer

Description

Winding Combs are used in disc wound dry type

transformers The winding comb mechanically

supports the turns of the coil while insulating each

turn from the others Although traditional designs

use 220°C rated material, some manufacturers have

successfully implemented 180°C rated materials in

some designs NEMA GPO-3, a 130°C rated material, is

commonly used for winding combs as well

The Gund Company custom fabricates dry type

winding combs with an automated CNC machining

center Each transformer’s combs are made

independently allowing for an infinite range of

designs This allows for a custom transformer winding configuration to meet the customer’s

requirements A normal transformer may require 24 to 36 combs depending on the design

Customers simply send a drawing, select a material, and receive a quotation A template

Winding Comb Order Form can be found in the appendix to facilitate a request for quotation

Typical lead-time for custom comb orders is two to four days

Standard features for The Gund Company’s winding combs include:

• Beveled, sharp edges to protect conductor

• Custom fabrication in small lot sizes

• Fastest lead-times in industry Please refer to the Appendix for a template Winding Comb Order Form for reference

Materials

• Glass Polyester Laminate, NEMA Grade GPO-3 (130°C)

• Glass Polyester Laminate, NEMA Grade N155 (155°C)

• Glass Polyester Laminate, NEMA Grade G-11 (155°C)

• Glass Polyester Laminate, Grade TWC-200 (180°C)

• Glass Polyester Laminate, Grade SG-200 (210°C)

• Glass Polyester Laminate, NEMA Grade N220 (220°C)

• Glass Epoxy Laminate, NEMA Grade G-10/FR4 (130°C)

• Glass Epoxy Laminate, Grade Isoval R (180°C)

Description

Coil shims are most commonly used in barrel wound dry type transformers The primary

purpose of coil shims is to tighten the coil windings in order to prevent potential vibration in

the unit

For dry type transformers, most company’s use a glass based laminate such as GPO-3 for

excellent mechanical strength

The Gund Company’s unique fabrication process for producing beveled or straight-edged coil

shims allows us to offer the lowest cost shims in the industry Custom shims can be shipped

within two to four days

Materials

• Glass Polyester Laminate, NEMA Grade GPO-1

• Glass Polyester Laminate, NEMA Grade GPO-3

• Glass Polyester Laminate, Grade N220, Grade SG-200, or Grade HST-II

Transformer coil wedges made with GPO-3 (Top) and GPO-1 (Bottom)

Air duct spacer sticks are used to provide clearances for the flow of air for the cooling

of transformer coils Their function is largely mechanical In large and medium power

transformers, spacer sticks are custom made to a particular profile and may be used in

conjunction with punched spacers to help position the conductor wire around the coil

In dry type transformers, spacer sticks are typically 220°C glass polyester pultruded rods often

called “dogbones,” appropriately named because of a commonly used version in that particular

• Pultruded Glass Polyester Rod Grade N155 or N220

• Pultruded Glass Polyester Rod Grade MTS, HIR, or SG-200

• Pultruded Glass Polyester Rod Grade

SuperSil™-“Dogbone” air duct spacer sticks between layers of Nomex™ on a barrel wound transformer

Section III Coil Support & Superstructure Components

Coil supports can be used throughout the transformer design to help add mechanical

strength and stability to a coil unit In most cases, coil supports are used to reduce potential

vibration while securing the coil firmly to the steel structural support of the transformer

Coil supports can be made to support the coil from the structural steel components from

above and below the coil depending on design

In dry type transformers, coil supports are typically made out of Glass Polyester Laminate

(NEMA GPO-1, NEMA High Temperature GPO-1 Grades, or NEMA GPO-3) For applications

requiring greater mechanical strength, Glass Epoxy Laminate, NEMA Grade G-10/FR4 or NEMA

Grade G-11 may be a better alternative

Materials

• Glass Polyester Laminate, NEMA Grades GPO-1, GPO-3

• Glass Polyester Laminate, Grades N220, SG-200, HST-II (NEMA GPO-1 High Temp Grades)

• Glass Epoxy Laminate, NEMA Grade G-10/FR4 or G-11

Coil supports on a dry type transformer made from GPO-3

Description

Insulating Fasteners including bolts, washers, and nuts are available from The Gund Company

in a variety of materials, sizes, and configurations Insulating fasteners offer high mechanical

strength and excellent dimensional stability at elevated temperatures

In many applications, insulating fasteners solve design issues by simplifying efforts to isolate

or ground conducting components of an assembly For instance, in some applications,

insulating nuts and bolts can replace a fastener assembly consisting of the metallic nut and

bolt as well as the required insulating bushing and insulating washer

Common applications include: transformer tap changers, transformer coil supports, lead

clamps, bus bar clamps, barrier supports, and many more designs requiring a non-conductive

fastener with excellent mechanical strength and stability at elevated temperatures

130°C

Switchgear applications, dry type transformer applications, motor lead clamp applications

Glass Epoxy High Pressure glass epoxy laminate with machined threads (Common

trade names include Durostone) 180°C

Power generator lead clamp applications, electrical furnace applications critical high strength / temperature applications

Insulating fasteners are available in English or Metric unit sizes Insulating bolts are

available with a full threaded bolt and a bolt with flat sides The flat side bolts allow

for easier threading, but provide less thread strength Standard nuts are square, but

hexagonal nuts can be manufactured at an additional cost upon request

Full Thread Bolt

Threaded rods are available with a full thread around the complete diameter of the rod This option offers the best thread strength

Flat Sides Bolt

Threaded rods are also available with flat sides

to allow for easier threading of the nuts This option can be produced more cost effectively, but provide less thread strength

Insulating Nuts & Bolts

Availability

Insulating fasteners are available in English or Metric unit sizes Insulating bolts are available

with a full threaded bolt and a bolt with flat sides The flat size bolts allow for easier threading,

but provide less thread strength Standard nuts are square, but hexagonal nuts can be

manufactured at an additional cost upon request

English Size Threaded Rods

Standard Thread Size Pressed Wood Glass Polyester Glass Epoxy

Metric Size Threaded Rods

Standard Thread Size Pressed Wood Glass Polyester Glass Epoxy

Tel (314) 423-5200 F

Insulating Nuts & Bolts

Availability

Insulating fasteners are available in English or Metric unit sizes Insulating bolts are available

with a full threaded bolt and a bolt with flat sides The flat side bolts allow for easier threading,

but provide less thread strength Standard nuts are square, but hexagonal nuts can be

manufactured at an additional cost upon request.

English Size Threaded Nuts

Standard Thread

Size Standard Thickness Range Standard Width Typical Description

¼” – 20 ¼” – ½” ½” ¼” thk x ¼”-20 ID x ½” Square 3/8” – 16 3/8” – ¾” 5/8” 3/8” thk x 3/8”-16 ID x 5/8” Square

½” - 13 ½” – 1” 7/8” ½” thk x ½” – 13 ID x 7/8” Square 5/8” - 11 5/8” – 1-1/4” 1” 5/8” thk x 5/8”-11 ID x 1” Square

¾” - 10 ¾” – 1-1/2” 1-1/4” ¾” thk x ¾” – 10 ID x 1-1/4” Square 7/8” - 9 7/8” – 1-3/4” 1-1/2” 7/8” thk x 7/8” – 9 x 1-1/2” Square 1” - 8 1” – 2” 1-5/8” 1” thk x 1” – 8 ID x 1-5/8” Square 1-1/4” – 11-1/2 1-1/4” – 2-1/2” 2” 1-1/4” thk x 1-1/4” – 11-1/2 x 2” Square 1-1/2” – 11-1/2 1-1/2” – 3” 2.5” 1-1/2” thk x 1-1/2” – 11-1/2 x 2.5” Square

Metric Size Threaded Nuts

Standard Thread

Size Standard Thickness Range Standard Width Typical Description

M6 6mm - 12mm 10mm 6mm thk x M7 ID x 10mm Square M8 8mm - 16mm 13mm 8mm thk x M8 ID x 13mm Square M10 10mm - 20mm 17mm 10mm thk x M10 ID x 17mm Square M12 12mm - 24mm 19mm 12mm thk x M12 x 19mm Square M14 14mm - 28mm 22mm 14mm thk x M14 x 22mm Square M16 16mm - 32mm 24mm 16mm thk x M16 x 24mm Square M18 18mm - 36mm 27mm 18mm thk x M18 x 27mm Square M20 20mm - 40mm 30mm 20mm thk x M20 x 30mm Square M24 24mm - 48mm 36mm 24mm thk x M24 x 36mm Square M27 27mm - 54mm 41mm 27mm thk x M27 x 41mm Square

ax (314) 423-9009

Insulating Nuts & Bolts

Description

The following chart indicates the typical properties for each of the insulating nut and bolt

materials All values indicated are typical minimum test values, but represent no guarantee It

is our recommendation to test all material in application prior to implementation.

Tel (314) 423-5200 F

Phase Barriers

Description

Phase barriers are used between the coils of a transformer to help prevent any phase

to phase faults The use of phase barriers helps to increase the creepage distance from

phase to phase allowing for closer placement of coils inside the transformer unit.

Dry type transformers use phase barriers manufactured from Glass Polyester Laminate,

NEMA Grade GPO-3 Typically, phase barriers are produced in thicknesses of 1/8”, 3/16”,

and 1/4” Phase barriers are custom fabricated as required according to the transformer

design.

Dry type transformers with attached switchgear also use phase barriers on the

switching side of the unit Phase barriers for switch side applications are most

commonly manufactured from Glass Polyester Laminate, NEMA Grade GPO-3.

Materials

Glass Polyester Laminate, NEMA Grade GPO-1

• Glass Polyester Laminate, NEMA Grade GPO-3

•

ax (314) 423-9009

Insulating Angles & Channels

Description

Insulating angles and channels are used in a wide variety of applications including:

Mechanically supporting bus bar

Insulating angles and channels are available in a wide range of standard sizes Typical wall

thickness for angles and channels varies from 1/8” up to 1/2” Along with a line of standard

angles and channels, The Gund Company can customize angles and channels to adjust leg

heights on channels and leg lengths on angles.

Channels and angles can be custom fabricated to include drilled holes, slots, and cutouts

according to the exact drawing requirements for a particular application.

Materials

Pultruded Glass Polyester, NEMA GPO-3

•

Tel (314) 423-5200 F

Stand-off Insulators

Description

Stand-off insulators are used to increase the creepage distance between two potentially

conductive components inside the transformer Some stand-off insulator designs incorporate

flanges to increase the arc distance Stand-offs may perform the following functions:

Mechanically supporting bus bar

• Insulating between steel structural members and current conducting components

• Providing non-conductive structural support

• The Gund Company supplies a wide range of stand-off insulators including the examples

shown below See the complete material data sheet information in the data sheet section of

this handbook

Materials

Compression Molded Glass Polyester, NEMA Grade GP0-3

•

ax (314) 423-9009

Section IV Transformer Tap Changer Components

Tel (314) 423-5200 F

Tap Changer Components

Description

The Gund Company can make a complete range of non-metallic, insulating components for

various tap changer designs including:

Terminal Boards Used for mounting contacts allowing for an insulating

medium to prevent current from passing between contacts.

Typical materials include:

Glass Polyester Laminate, NEMA Grade GPO-1 Glass Polyester Laminate, NEMA Grade GPO-3 Glass Polyester Laminate, Grade SG-200 Glass Polyester Laminate, Grade HST-II Glass Polyester Laminate, Grade N220 Low-Power Factor Paper Phenolic, NEMA Grade LPF206.15

Insulated Shafts for Drive

Mechanism

Used for mounting contacts allowing for an insulating medium to prevent current from passing between contacts.

Typical materials include:

Glass Polyester Laminate, NEMA Grade GPO-1 Glass Polyester Laminate, NEMA Grade GPO-3 Glass Polyester Laminate, Grade SG-200 Glass Polyester Laminate, Grade HST-II Glass Polyester Laminate, Grade N220

Non-metallic Gears To prevent current from passing along the drive

mechanism, non-metallic gears can be used.

Typical materials include:

Canvas Phenolic Laminate, NEMA Grade C Glass Epoxy Laminate, NEMA Grade G-10

Insulating Tubing Insulating tubing and bushings are used to insulate

metallic, conductive fasteners such as connecting rods and bolts Insulating tubing can also be used to protect routing paths for leads and cables.

Typical materials include:

Glass Epoxy Laminate, NEMA G-10/FR 4 Glass Epoxy Laminate, NEMA G-11

ax (314) 423-9009

Section V Material Data Sheets

Tel (314) 423-5200 F

MANUFACTURERS OF

ELECTRICAL INSULATION MATERIALS

INSULATING COMPONENTS FOR POWER SYSTEMS EQUIPMENT

The Gund Company, Inc

St Louis, Missouri – USA

TEL - 314.423.5200FAX - 314.423.9009

MATERIAL DATA SHEET

Description: NEMA Grade G-10/FR4 material is a continuous filament woven fiberglass sheet bonded with epoxy

resin The material has the ability to maintain excellent mechanical, electrical, and physical properties

at elevated temperatures to 130°C

IEC 60893MIL-I-24768

122 cm x 243.8 cm, 122 cm x 274.3 cm

Convolute Tubing: Available in an infinite number of inner diameter/outer diameter combinations

as per customer requirements

Fabricated Parts: The Gund Company custom fabricates insulation materials to the exact

specifications and drawings of our customers

Key Characteristics Test Method Units - English (SI) Typical Values

Tensile Strength (.125”) LW

CW ASTM D-638 psi (MPa) 40,000 (275)32,000 (220)Compressive Strength, Flatwise (.50”) ASTM D-695 psi (MPa) 66,000 (455)Flexural Strength (.062”) LW

CW ASTM D-790 psi (MPa) 65,000 (448)52,000 (358)Flexural Modulus (.062”) LW

CW ASTM D-790 ksi (MPa) 2,900 (19,995)2,600 (17,926)Shear Strength, Perpendicular (.062”) ASTM D-732 psi (MPa) 21,500 (148)IZOD Impact Strength LW

CW ASTM D-256 ft.-lbs./in.Notched 7.97.3

Breakdown Voltage (.062”) Condition A D-48/50 ASTM D-149 kV 6665Dielectric Strength (.062”) Condition A

D-48/50 ASTM D-149 V/mil 800750

All of the information, suggestions, and recommendations pertaining to the properties and uses of the products herein are based upon tests and data

believed to be accurate; however, the final determination regarding the suitability of any material described herein for the use contemplated, the manner

ax (314) 423-9009

MANUFACTURERS OF

ELECTRICAL INSULATION MATERIALS

INSULATING COMPONENTS FOR POWER SYSTEMS EQUIPMENT

The Gund Company, Inc

St Louis, Missouri – USA

TEL - 314.423.5200FAX - 314.423.9009

MATERIAL DATA SHEET

Description: NEMA Grade G-11 MC511AF is a high pressure laminate manufactured from a glass cloth substrate

impregnated with a high temperature epoxy resin system This grade meets or exceeds all specifications for NEMA G-11 material

IEC 60893MIL-I-24768

Fabricated Parts: The Gund Company custom fabricates insulation materials to the exact

specifications and drawings of our customers

Key Characteristics Test Method Units - English (SI) Typical Values

Tensile Strength, Lengthwise (.125”) ASTM D-638 psi (MPa) 41,000 (282.5)

Compressive Strength (.125”) ASTM D-695 psi (MPa) 50,000 (344.5)

Flexural Strength, Lengthwise (.125”) ASTM D-790 psi (MPa) 57,000 (392.7)

Shear Strength, Perpendicular (.062”) ASTM D-732 psi (MPa) 21,000 (144.7)

IZOD Impact Strength Lengthwise (.125”)

ASTM D-256 ft.-lbs./in.Notched 10.0

Temperature Index, Electrical

Mechanical °C 170180

Dielectric Strength, Perp - Short Time (.125”) V/mil 550

All of the information, suggestions, and recommendations pertaining to the properties and uses of the products herein are based upon tests and data

believed to be accurate; however, the final determination regarding the suitability of any material described herein for the use contemplated, the manner

of such use, and whether the use infringes any patents is the sole responsibility of the user There is no warranty, expressed or implied, including, without