Envirotemp® FR3® Fluid Cold Temperature Performance

January 21, 2008

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FR3 Fluid Benefits

Environmental– Rapidly & Completely Biodegradable– Renewable Resource

Fire Safety– Easy Safety Code Compliance

• Indoors & Near Buildings

Enhanced Insulation Performance– Extends Paper Thermal Life – Asset Life Extension or Increased Loading Possible

FR3 Fluid = Innovative Transformer TechnologyFR3 Fluid = Innovative Transformer Technology

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FR3 Fluid Cold Performance

Higher Viscosity & Pour Point May Affect Handling & Storage Procedures– Heating Required for Pump Rates Similar to Mineral Oil

Water Saturation Very Unlikely– Significant Risk of Free Water in Cold Mineral Oil

Maintains Dielectric Strength at Low Temperatures

Reliable Cold Dielectric PerformanceReliable Cold Dielectric Performance

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Cold Performance - Distribution

Transformer Cold Start– Passed Sudden 100% Load Tests at – 30 C (- 22 F)– No Load Losses Sufficient to Warm Fluid

Distribution Transformer Components – Sectionalizing LB Switches – Full Ratings to -20 C– Bayonet & ELSP – Full Ratings to – 20 C– NL Tap Changer Operation to -20 C– VFI Operation to -10C– Magnex Operation to 0 C

CPS Voltage Regulators– Automatic Motor Operation Lock-Out at -10 C– No Load Losses Sufficient to Warm Fluid

No Cold Temperature Field Problems ReportedNo Cold Temperature Field Problems Reported

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Cold Performance Power Transformers

LTC

– Thermal Lock-Out at -10 C Recommended– Synthetic Ester Alternative (- 60 C Pour Point)

Forced Oil Cooling Pumps– Case-by-Case Approval, but typically OK– Overcurrent Protection Adjustments for Cold Start– Special Shutdown & Start-Up Procedures to Keep Oil in Radiators Warm

Radiators – Tests Confirm Self Clearing During Cold Start

Case-By-Case Evaluation – Typically PositiveCase-By-Case Evaluation – Typically Positive

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Climatic Data

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Climatic Data

Taken from NOAA data filesTypical parameters are:

– Annual record extreme minimum– Annual mean extreme minimum

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Annual Record Extreme Minimum

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Annual Mean Extreme Minimum

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Climatic Data By City

Lowest Daily Temp (Record Extreme) and Lowest Daily Ave Temp (24-hour period).

Number of occurrences at 1 and 3 day periods

Relate to FR3 fluid properties at time and temperature

Related to FR3 Fluid in a Transformer

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Typical Climatic Data

Historical Data: Chicago O’Hare 111549

From 1980-2001

Lowest Daily Temperature: -27FLowest Daily Temperature: -27F

Lowest Daily Average Temperature: -18FLowest Daily Average Temperature: -18F

14X 12X

1.1X 0.8X

0.2X 0.0X

14X 12X

1.1X 0.8X

0.2X 0.0X

Average Occurrences/year Average Occurrences/year for for 1-day and 3-day1-day and 3-day

FR3 fluid properties for a FR3 fluid properties for a given temperature and timegiven temperature and time

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Map of Climatic Data

Click on city name for additional details

Annual Mean Extreme Minimum Temperature

Albert Lea, MN

Lansing, MI

Fargo, ND

International Falls, MN

Minneapolis, MNPierre,

SD

Dubuque, IACedar Rapids,

IA

Fon Du Lac, WI

Milwaukee, WI Chicago, IL

Rockford, IL

Bangor, ME

Hightstown, NJ

Philadelphia, PA

Roanoke, VA

Boise, ID

Lincoln, NE

Olympia, WA

Salem, OR

Cheyenne, WY

Denver, CO

Billings, MT

Ft. Wayne, IN

Columbus, OH

Helena, MT

Salt Lake City, UT

Albany, NY

New York, NY

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Climatic Data

Conclusion: Periods of extended cold are less often and less extreme than intuitive

For example, Chicago:– Number of occurrences of –20C (-4F) are

only:• 1-day: Once/year• 3-day: Once every 2 years

– Number of occurrences of –25C (-13F):• 1-day: Only once every 10 years

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