1. All transformers are NOT created equal

2. Liquid vs. Dry Transformers
Meet safety codes, both indoors and out.
In the United States, the National Electric Code has been expanded to include a section on the
use of less flammable liquids for outdoor applications. This recognizes the value of specifying
these liquids—which have long been used indoors—for sensitive outdoor installations.
Unlike dry transformer designs, liquid designs using 561® Transformer Fluid from
Dow Corning cool as well as insulate, making them the ideal choice for a range of different
indoor and outdoor sites. Liquid transformers also run quieter and take up less space than their
dry counterparts.
Realize greater efficiency over dry types.
For years, utility companies have recognized the value of liquid transformers over dry designs. In
addition to reliability and long life, utilities also demand high efficiency.
Since all of the power delivered through a transformer directly affects its efficiency, a differ-
ence of only 0.5 percent in the efficiency of a 2,000 kVA unit running at 50 percent of rated load
can add up to 43,800 kilowatt hours each year. When you consider that a transformer’s lifespan is
typically 25 years or more, this adds up to a huge cost savings.
When you also consider that dry designs may be difficult, if not impossible, to repair and that
the coils may not be recyclable, the full advantage of liquid designs becomes obvious.
As you can see, a liquid transformer filled with 561 Transformer Fluid can easily pay for itself
and much more.
For the most efficient design ... choose LIQUID.
Comparing Liquid Alternatives
Achieve long-term performance and reliability.
561 Transformer Fluid is extremely stable, both electrically and thermally. As a result, it can
maintain its insulating and cooling properties for extended periods of time, even at very high
temperatures.
In addition, silicone transformer fluid has excellent oxidation resistance, which deters the
formation of degradation products or sludging. And its high chemical stability and crystal clarity
allow you to check for foreign materials at a glance.
This stability translates into less maintenance, which in turn adds up to lower costs for you.
561 Transformer Fluid R-Temp Fluid Mineral Oil
AV03209
AV032010
AV03208
561 Transformer Fluid (left) demonstrates superior chemical stability and clarity compared with R-Temp®1 fluid (middle) and
mineral oil (right). The samples show unaged material on the left and material aged for 500 hr. @ 100°C on the right.
1
R-Temp is a registered trademark of Cooper Power Systems, Inc.
©1998 Dow Corning Corporation. All rights reserved.
F.C. Photos: AV00215, AV03315, AV03314, AV02920, AV03308, 00605-5, AV00216

3. Protect people, buildings and equipment.
Silicone fluid has a significantly better fire impact profile than any other type of
material in its class. In fact, it has a significantly lower heat release rate, lower
smoke generation, and lower toxicity of combustion by-products than its
competitors.
Several studies by third-party investigators, including
Factory Mutual, Underwriters Laboratories, and
AV03261
Southwest Research Institute, have clearly concluded that
in the event of fire, silicone fluid is the best performing
material, when compared to mineral oil and High- 561® Transformer Fluid for
Molecular-Weight Hydrocarbon (HMWH) oil.
indoor applications helps
protect museum
With the help of 561
AV03211
Silicone transformer fluid pro- Transformer Fluid from
duced an average of one-tenth
High-Molecular- Dow Corning, the new $1
as much heat and one-fifth as
Weight
much carbon monoxide as High- billion Getty Center in
Hydrocarbon
Molecular-Weight Hydrocarbon
(HMWH) suburban Los Angeles
(HMWH) in a fact-finding
AV03212
investigation conducted at
provides a stable protective
Underwriters Laboratories.
561 Transformer Fluid environment for the
museum’s collections.
Address important environmental issues. The facility’s power deliv-
The potential for toxicity, bioaccumulation, and ultimate fate of a material ery system is a crucial part
during its useful life and beyond are important considerations. 561 Transformer
of the design. The system
Fluid is an excellent choice for low toxicity, non-bioaccumulation, and
recyclability. At the end of its useful life, 561 Transformer Fluid can usually must provide an extremely
be recycled. reliable, temperature-
In cases where 561 Transformer Fluid is exposed to the environment
and humidity-controlled
through spill or accidental release, it has low toxicity and will not bioaccumulate.
561 Transformer Fluid degrades in soil into silica, carbon dioxide, and water. climate, and help ensure
561 has extremely low water solubility and in the case of a spill into water, the critical fire safety.
fluid will initially float on the surface, aiding clean up. Eventually, any residual
will absorb onto particles and settle into the sediment where it will degrade. Specifiers chose 561
Ready biodegration of fluids can result in oxygen depletion in water and cause Transformer Fluid because
harm to aquatic life. 561 Transformer Fluid will not biodegrade in water, but
will degrade after settling into sediment at a rate that will not significantly silicone’s high flash point
deplete oxygen. and low heat release
Silicone fluid has a very favorable environmental profile. offered the museum an
2698
added measure of safety
For the best performing liquid insulation ... choose SILICONE. over competing materials.
561
®
It takes the heat,
so you don’t have to.
Silicone Transformer Fluid

4. When the answer is a silicone,
liquid-type transformer, rely on
561 Transformer Fluid.
561 Transformer Fluid is the only UL classified silicone transformer fluid
on the market. That means there’s no more wondering about whether your
transformer will meet code.
And, there’s no need to worry about disposal, either. In 1996,
Dow Corning initiated a Registration and Recycling program for
561 Transformer Fluid. This program can help reduce your concerns about
future disposal costs and provide a cost-effective, environmentally acceptable
alternative to disposal.
Selecting the best transformer may seem like a difficult task, but with
the right information—backed by Dow Corning’s proven applications and
more than 20 years of testing—a tough decision can be made easy.
We want to ensure you get what you want.
A full model specification can be obtained from Dow Corning at the
numbers below. However, the following points should be incorporated into
any specification for silicone fluid to make sure you get its full value:
■ The dielectric coolant shall be a listed, less-flammable fluid meeting
AV01783
the requirements of the National Electric Code 450-23, including a
With its high flash and fire points, 561 Transformer minimum fire point of 300°C.
Fluid presents a very low fire hazard. ■ The fluid shall be non-hazardous, non-bioaccumulating, and exhibit
low toxicity.
■ The fluid shall be degradable in soils and sediments.
■ The fluid shall not cause oxygen depletion (starvation) in water.
■ The fluid shall be approved per Factory Mutual P7825. Total heat
release rate shall not exceed 150 kW/m2.
■ The fluid shall be classified by Underwriters Laboratories as a dielec-
tric medium per UL category EOUV. The fluid shall also be classified
as a transformer fluid per UL category EOVK.
■ Liquid viscosity shall not exceed 100 mm2/s at 0° as tested per ASTM
D 445, D 2161.
For more information, or to speak to a Dow Corning representative, please
call: In the USA: 1-800-HELP-561 or 1-517-496-6000
In Canada: 1-905-826-9600
In Mexico: 1-525-327-1300
The information and data contained herein are based on information we believe reliable. You should
thoroughly test any application and independently conclude satisfactory performance before use.
Suggestions of uses should not be taken as inducements to infringe any particular patent.
Dow Corning and 561 are registered trademarks of Dow Corning Corporation.
Printed in U.S.A. AMPM0454/1297 Form No. 10-783-98
Dow Corning Corporation
Midland, Michigan 48686-0994