Global Energy Solutions Frequent Questions Answers for

Global Energy Solutions Frequent Questions & Answers for Du. Pont. TM Reliatra. N® Version 1 dated June, 2003 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 1 PERFORM WHEN THE HEAT’S ON

Global Energy Solutions n Contents n What is Reliatra. N® n Reliatra. N® page 5 ~ 6 Criteria page 7 n What is NOMEX®? page 8 ~ 15 n. What are the major advantages of page 16 n What are the benefits to the users of page 17 n How does Du. Pont maintain the high quality page 18 ~ 20 Reliatra. N ® Brand Transformers ? and reliability of Reliatra. N® transformers? n How does Reliatra. N® perform under moisture? page 21 ~ 27 2 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Global Energy Solutions n Contents n. How does Reliatra. N® perform under dirty condition? page 28 ~ 29 n What’s the meaning of load loss by various insulation class? page 30 ~ 33 n How is dielectric withstand of Reliatra. N® ? page 34 ~ 35 n How well does Reliatra. N® perform during overloading? page 36 ~ 37 n How well does Reliatra. N® withstand short circuit ? page 38 n What is the fire behavior of Reliatra. N® ? page 39 ~ 45 3 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Global Energy Solutions n Contents n How is Reliatra. N® environmentally friendly ? page 46 ~ 48 n What does partial discharge mean to dry type transformer ? page 49 n What is VPI process ? page 50 ~ 51 n What is the maximum rating of Reliatra. N® n Index transformers? page 52 page 53 4 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Global Energy Solutions n What is Reliatra. N® ? Reliatra. N® is poised to be the chosen brand for value-added transformer solutions that apply to various distribution transformer applications. n 5 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Providing Global Energy Solutions to the Electrical Industry Du. Pont. TM Reliatra. N® Brand Transformers are manufactured with UL® Certified Insulation Materials , by a global network of ISO 9001 Certified Manufacturers, meeting the highest of International Standards for Quality, Design, Construction and Performance Du. Pont. TM Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 6 PERFORM WHEN THE HEAT’S ON

Global Energy Solutions n Du. Pont. TM Reliatra. N® Criteria The Reliatra. N® standards are continuously reviewed to incorporate new experience, materials, test procedures, etc or to adapt new requirements n 7 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Global Energy Solutions n What is NOMEX® ? n. The superior electrical properties of NOMEX® paper and pressboard provide unique capabilities for electrical equipment, resulting in new classes and ratings. This includes: n n High Level of Safety Increased Load Capability Reduced Size and Weight Long Term Reliability 8 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Global Energy Solutions NOMEX® Electrical Insulation has been used in the most critical applications in all types of electrical equipment. n Resin Cast Transformers Ventilated Dry Transformers Generators AC/DC Motors Reactors Gas Filled Transformers Liquid Immersed Transformers Hermetic Motors 9 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Global Energy Solutions The Advantages of NOMEX® The unique capabilities of materials made from Nomex® aramid polymer are a result of it’s superior Thermal, Chemical, Mechanical and Electrical properties 10 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Global Energy Solutions The Advantages of NOMEX® THERMAL n n Long Term Stability up to 220°C Short term exposures up to 350°C is possible Stable properties over a wide range of temperature and humidity conditions Will not Melt, Flow or Support Combustion below 250°C, with no toxic or corrosive Off-Gases below 750°C NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 11 PERFORM WHEN THE HEAT’S ON

Global Energy Solutions The Advantages of NOMEX® O CHEMICAL N H O N C H C n n No weak C-H bonds creates a strong resistance to chemical attack by acids and alkalis n Compatible with all oils, resins, varnishes, fluorocarbons, refrigerants 12 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Global Energy Solutions The Advantages of NOMEX® MECHANICAL n n n High tensile strength and tear resistance prevent manufacturing problems High abrasion and cut resistance prevent production and operational failures Good compression resistance provides a stable and rigid structure during short circuit or other mechanical stresses 13 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Global Energy Solutions The Advantages of NOMEX® ELECTRICAL n n The low Dielectric Constant enables better distribution of stresses between the insulation and the cooling medium The low Dissipation Factor, even at high temperatures, reduces dielectric loss High Resistivity at high temperatures up to 250°C in use Excellent Dielectric Strength under 50/60 Hz and under impulse conditions 14 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

The Advantages of Nomex® is a Du. Pont Registered Trademark 15

n What are the major advantages of Du. Pont. TM Reliatra. N® Brand Transformers ? n These State-of-the-Art ventilated dry type transformers provide the best solution in reliable and versatile equipment • Safe equipment which can be placed close to the load • Flexibility in variable load situations • Increased overload emergency capability • Reduced Size and Weight for better space utilization • Economical solutions for the distribution of power Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 16 PERFORM WHEN THE HEAT’S ON

n What are the benefits to the users of Du. Pont. TM Reliatra. N® Brand Transformers ? n n n Highest Quality Standards • Du. Pont standards for design and manufacture exceed the local and global standards to ensure high quality and reliability / long life Longest Warranty • Du. Pont’s network of qualified manufacturers of Reliatra. N® transformers offer unprecedented five (5) years warranty Cost Savings • Lowest total owning cost from purchase to disposal over the lifetime of the equipment Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 17 PERFORM WHEN THE HEAT’S ON

n How does Du. Pont maintain the high quality and reliability of Du. Pont. TM Reliatra. N® transformers? n n Du. Pont provides the most updated technology on design, manufacturing and testing to partners and continuously monitors and audits all aspects of production to deliver quality without any failure. Simple processing enables OEMs to produce constant quality and reliability. All processes are visible to detect any potential defect of transformer. Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 18 PERFORM WHEN THE HEAT’S ON

Coil Manufacturing Process Cast coil VDT Assemble mold - Preheat resin - Weigh resin Sophisticated process/ - many parameters to Mix resin quality impact Simple process/ - less parameters pouring curing Disassemble mold Impregnation(VPI) to quality impact drying 19

1. n One of the special requirements for the transformer installed at Nuclear Power Plant is longer life ( 40 years). VDT had been used in many Nuclear Power Plants in US due to reliable long life Failure rate of VDT at field is less than half of that of other dry transformers in US. Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 20 PERFORM WHEN THE HEAT’S ON

n How does Du. Pont. TM Reliatra. N® perform under moisture? n n n NOMEX® itself has high resistance under high humidity. VPI processing assure that windings are well protected against harsh environment such as moisture and dust. Many tests and historical cases at operation sites have proved that VDTs were safe to operate without outage at high humid conditions. Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 21 PERFORM WHEN THE HEAT’S ON

n If a dry type transformer is energized after long storage period under high humidity, it is recommended either to wipe dirt and moisture or to energize without loading before placing a load on transformer. n We do not recommend starting or operating a transformer with free moisture on the coils as there may be surface deposits that are conductive when wet. Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 22 PERFORM WHEN THE HEAT’S ON

Relative Volume Resistivity of Materials (ohm - cm) 1020 Nomex® { 50°C 1016 220°C 1012 108 100 10 -6 10 -10 } } Insulators Semiconductors Conductors Superconductors Nomex® is a Du. Pont Registered Trademark 23

Relative Volume Resistivity of Materials (ohm - cm) 1020 Epoxy Resin { 50°C 100°C 150°C 1016 1012 108 100 10 -6 10 -10 } } Insulators Semiconductors Conductors Superconductors 24 Nomex® is a Du. Pont Registered Trademark

Superior Humidity Resistance * Relative Dielectric Dissipation Volume Humidity Constant Factor Resistivity (%) (60 Hz) (ohm- cm) ___________________________ Dry 2. 5 0. 006 1016 50 2. 7 0. 006 1016 95 3. 2 0. 011 1014 * Properties for Nomex® 10 mil (0. 25 mm) T-410 Nomex® is a Du. Pont Registered Trademark 25

Moisture resistance of VDT insulated with NOMEX® A 1000 KVA ventilated dry type transformer with NOMEX® insulation was used in a special moisture demonstration by exciting the transformer at full voltage immediately after being in a thunderstorm. Transformer description It is 1000 KVA rated 13800 volts primary and 480 Y volts secondary. The temperature rating is 150 C rise at a max. ambient of 40 C. The BIL rating of the high voltage is 95 KV. The prior history of the transformer includes a short circuit test and impulse test following the short circuit test. The transformer was then subjected to higher impulses and subsequently flashed over at 138 KV. The partial discharge inception voltage when tested as individual coils was 1. 9 times rated voltage at 400 Hertz excitation. The Demonstration The transformer was placed outdoors during an extremely severe thunderstorm. The thunderstorm lasted about one hour and 1. 5 inches of rain fell. Immediately there after, the transformer was brought to the testing area and excitation was applied. The transformer withstood its full operating voltage with no sign of imminent flashover. Nomex® is a Du. Pont Registered Trademark 26

Moisture resistance of VDT insulated with NOMEX® Conclusion The NOMEX® insulated ventilated dry type transformer with VPI treatment exhibits superior moisture resistance and can be used in outdoor locations in a properly designed outdoor enclosure. The thunderstorm demonstration was performed to show the superior moisture resistance of coil construction. Case study by Southern Transformer Co. Alexander D. Kline, President Nomex® is a Du. Pont Registered Trademark 27

n How does Du. Pont. TM Reliatra. N® perform under dirty condition? Coil structure is well constructed to separate each disk, which will not allow cumulative dust collection between disks. n Enough cooling space in LV, gap between LV/HV and HV ensure effective cooling even at harsh environment such as cement plants and mines n One ASEAN power utility has operated several VDTs for more than 15 years without any maintenance at all, though a thick layer of dust covered windings. n Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 28 PERFORM WHEN THE HEAT’S ON

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n What’s the meaning of load loss by various insulation class? The higher insulation class makes it possible to build smaller size of coils, eventually leading to smaller transformer size. n The one of the advantages of H class dry type transformer is compactness and lower no load loss with more load loss compared with other transformers below H class. n Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 30 PERFORM WHEN THE HEAT’S ON

n Most of transformers operate at significantly below the full rated load(average 60%) which benefits lower no load loss in terms of economic view. n Therefore, higher temperature designs more fully utilize the raw materials and optimize losses, which is the growing trend in the West. n Reliatran® can be built for specific load loss, lower than standard class H transformer by request. Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 31 PERFORM WHEN THE HEAT’S ON

0. 94 32

n Higher winding temperatures allow smaller coils and smaller magnetic cores, saving cost, space and weight. Temp. Class Coil Size Comparison (% of Class H) Class B Class F Class H Class C 130 115 100 90 33 NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

n How is dielectric withstand of Du. Pont. TM Reliatra. N® ? n Due to lower dielectric constant of NOMEX® than other insulation materials, It has better distribution of stresses throughout transformer n There is no thick layer of Epoxy resin which means “No cracking” on coils. One of the common problems with cast coil is cracking to cause failure. Disk winding structure distributes the voltage stress evenly and efficiently to meet BIL requirement of all is a Trademark of E. I. Du. Pont de Nemours and Co. 34 standards. n Reliatra. N® NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

NOMEX® Brand Paper & Pressboard The Dielectric Constant of NOMEX® sheet insulation is very low compared to most insulating materials. Nomex® Inorganics Glass Epoxy 1. 5 -2. 5 3. 0 -5. 0 -6. 0 4. 0 -6. 0 Air Mineral Oil Silicone Cellulose 1. 0 2. 2 2. 7 4. 5 The closer to the cooling medium(air), the better the distribution of stresses throughout the transformer. Nomex® is a Du. Pont Registered Trademark 35

n How well does Du. Pont. TM Reliatra. N® perform during overloading? Based on GB standard, the average winding rise is 125 C and max. hottest temperature is 180 C. n In this case there is temperature margin which is 40 C differential between thermal capability of Nomex(220 C) and max. hottest temperature(180 C). This contributes to higher overloading capability. n For certain cases, one can put dual ratings on the name plate for flexible operation either with lower load loss or higher capacity. n Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 36 PERFORM WHEN THE HEAT’S ON

• Steady State Loading on the Basis of test temperature rise (Quoted from ANSI C 59. 96 -IEEE Guide for Loading Dry type distribution and power transformer) Rated average winding temperature rise For each degree C below the rated temperature rise, increase rated load by 80 C 0. 57% 115 C 0. 43% 150 C 0. 35% If a 1000 KVA is 100 C average winding temperature rise, the additional rating for over loading can be calculated. (115 C - 100 C) x 0. 43% + (150 C - 115 C) x 0. 35% = 18. 7% ===> 1000 KVA x 1. 187 = 1187 KVA * Note: In general, Reliatra. N® provides about 30% additional capability for overloading based on practical design. Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 37 PERFORM WHEN THE HEAT’S ON

n How well does Du. Pont. TM Reliatra. N® withstand short circuit ? Design principles utilized for these transformers minimize axial and radial mechanical forces in case of short circuit accident. n Transformers using this design have passed short circuit tests mechanically and thermally for more than 30 years (in the US). n VPI process with varnish enhances mechanical strength of coils to prevent failure by short circuit accident. n In addition, the disk structure in HV coil can hold winding robustly. n Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 38 PERFORM WHEN THE HEAT’S ON

n What is the fire behavior of Du. Pont. TM Reliatra. N® ? Aramids do not melt (hence it will not help the fire to spread) and generate little or no smoke and emit no toxic gas. n Epoxy resin may emit some toxic gases when decomposed by fire such as SO 2, hydrogen sulfides and halides [Ref. 1] n Specialty tests like CENELEC HD-464 indicate that VDT had less smoke, less weight loss, quicker self extinguishment , less support to combustion than cast coil n Nomex does not support combustion and can only be burned with difficulty - even at elevated temperature is a Trademark of E. I. Du. Pont de Nemours and Co. 39 (LOI >> 21%) n Reliatra. N® NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. PERFORM WHEN THE HEAT’S ON

Quoted from “Development of Insulating Systems in Distribution Transformers - Improvement of Fire Resistant Characteristic” by G. LE ROY and F. SANDOZ “Full size testing of distribution transformer behavior under fire has been possible thanks to the building by the French Coal Board Research Center (CERCHAR) of a “fire gallery” guaranteeing against all environment pollution risks” n n“Class H VDT: only slight effects occurred after some times - pyrolysis of the superficial varnishes and metal frame paints ---. Let us note that this good behavior is a consequence of the choice of materials done on this equipment, on the basis of systematic fire test on samples(oxygen index at various temperatures, combustion gas analysis). Class B cast coil: Contrary to class H VDT, this equipment behavior was rather disappointing and even, in some way, surprising. About 3 minutes after being exposed to fire, whilest temperature reached only about 150 C , the transformer went into flames. In spite of the radiating panels being switched off, combustion self supported itself until insulating matters complete destruction. Conclusion: “ Especially the class H VDT, the only one having shown a completely satisfactory behavior during the full size fire test. ” n 40

Quoted from “Development of Insulating Systems in Distribution Transformers - Improvement of Fire Resistant Characteristic” by G. LE ROY and F. SANDOZ Transformer type VDT Cast coil Silicon Ugilec T Class H(Aramid) Class B 630 - 400 - 250 190/40 First fire occurrence (min): 30 3 30 20 Fire end (min): 40 70 110 55 Rating(KVA): mass tank/vessel (kg): Total energy measured at 12 m from the fire (MJ after 40/60 min): Energy emitted by radiating panels (MJ): 225/225 700/4900 143 ** 80 336 95 338/60 400/500 Combustible destruction part (%) 20 100 336 55 20 Released carbon dioxide mass(kg): 10 0. 15 100 300 75 Transformer part in total energy (%): Released HC 1 mass(kg): Released soot And dust mass (kg): 336 <1 600/640 250 Liquid 0. 5 ** Panels shut off owing to fire evolution 180 25 1. 5 41

Flammability of insulation materials in transformer Limiting Oxygen Index (%) Limiting Oxygen Index vs. Temperature 40 0. 13 mm. Nomex 0. 13 mm PET Film 6 mm Epoxy/Filler 30 20 100 200 300 Temperature (°C) NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 400 42 PERFORM WHEN THE HEAT’S ON

CENELEC Norm HD-464 Testing for the European Community 1. Severe Environments [ E ] • Humidity Saturation at 50°C / 95% RH / 72 Hrs - Must Successfully pass lightning impulse, power frequency withstand voltage, and measurement of partial discharge • Saline Condensation at 93% RH / Saline Haze of Na. Cl / 144 hrs / Running with water - Must successfully pass overvoltage and power frequency withstand voltage 43

CENELEC Norm HD-464 Testing for the European Community 2. Thermic Impulse Test [ C ] • Thermic Impulse test from -25°C to + 100°C within 40 minutes - Must pass impulse and partial discharge tests 3. Fire Testing [ F ] • Winding subjected to pilot flame with heat source of 800°C for 40 minutes - During test, measure toxic off-gasses and smoke emission - After flame removal, measure time to extinction, and weight loss 44

NOMEX® Insulated Transformer Coil Subjected to CENELEC HD-464 Fire Test [%] [K] Fire Test Behavior According to HD 464 Temperature Rise and Optical Transmission Factor [OTF] 45

n How is Du. Pont. TM Reliatra. N® environmentally friendly ? n When disposing NOMEX® by burning or burying, it does not emit toxicity to contaminate soil and air. Therefore NOMEX® can be recycled for fuel as energy source, which was certified by European Cement plant n Burying waste of epoxy resin is costly. Incineraton of epoxy is not recommended due to potential hazardous off-gases NOMEX® can be incinerated at common furnace is a Trademark of E. I. Du. Pont de Nemours and Co. operating temperatures. n Reliatra. N® NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 46 PERFORM WHEN THE HEAT’S ON

n There is no waste of varnish after impregnation process while cast coil should over-prepare epoxy resin to fill cast mold with redundancy against shrinkage/leakage. The waste at mixer and cast mold should be disposed carefully not to impact environment. n Cast coils leave particlulates with Epoxy resin and glass materials when disposed. These materials are not present in VDT coils. n When cast coil is ground for removing sharp edges, the dust which is mixture of glass and Epoxy resin may impact comfortable environment. Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 47 PERFORM WHEN THE HEAT’S ON

n There are no materials in VDT coils causing allergy and itch to human body n The quantity of materials requiring disposal is significantly less than with cast resin coils (> 4 times) n Compact size with lighter weight require less active parts, which contributes for energy saving and green environment. (Production of silicon steel/copper wire entails fossil fuel consumption resulting in air/water pollution. ) Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 48 PERFORM WHEN THE HEAT’S ON

n What does partial discharge mean to dry type transformer ? n Reliatran® has a thinner layer of varnish without any possible air bubble inside and is designed to have low voltage stress far below corona inception voltage. n Cast coil transformers assume the epoxy resin fill the gaps and therefore design for epoxy dielectric, assuming no air if any air bubbles appear, there will be high stress on the air and partial discharge will develop. It may cause insulation breakdown resulting in transformer failure. Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 49 PERFORM WHEN THE HEAT’S ON

n What is VPI process ? n This is the most evolved technology to produce high quality coils with advanced equipment and material. n Impregnation is done inside tank under vacuum/pressure condition and there are no varnish drops outside tank. Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 50 PERFORM WHEN THE HEAT’S ON

n During curing , there is some evaporation of solventless varnish due to cross linking process between monomers and resin. The vapor is not toxic and is exhausted out by oven chimney. Varnish does not cause skin irritation or allergic reaction to people. n Excess varnish can be returned to storage the tank after impregnation process without any waste. Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 51 PERFORM WHEN THE HEAT’S ON

n What is the maximum rating of Du. Pont. TM Reliatra. N® transformers? n VDT transformers have been produced up to 15 MVA and 35 KV voltage class. Most popular range of product is up to 3000 KVA. In general, Power Utilities limit electricity supply to users below 10 MVA as max. due to distribution reliability and economic reasons. Du. Pont. TM Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 52 PERFORM WHEN THE HEAT’S ON

n Index n 1. ”Safety Aspects of Using Aramid and Paper and Pressboard in Dry Type Transformer” Dr. J. W. Rothuizen/ Switzerand n 2. ”Development of Insulating Systems in Distribution Transformers Improvement of Fire Resistant Characteristics” G. LE Roy/ F. Sandoz/France n 3. “Moisture Resistance of Nomex - Insulated “Glazed Coils”” Alexander D. Kline/USA n 4. ANSI C 59. 96 - IEEE Guide for Loading Dry Type Distribution and Power Transformer n 5. CENELEC Norm HD 464 - Specialty test for Severe Environments, Thermic Impulse and Fire Reliatra. N® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 53 PERFORM WHEN THE HEAT’S ON

PAPER AND PRESSBOARD UL RECOGNIZED Global Energy Solutions Du. Pont. TM Reliatra. N ® is a Trademark of E. I. Du. Pont de Nemours and Co. NOMEX ® is a Registered Trademark of E. I. Du. Pont de Nemours & Co. 54 PERFORM WHEN THE HEAT’S ON