Square D is an
American manufacturer of
electrical equipment
Electric(al) devices are devices that functionally rely on electric energy ( AC or DC) to drive their core parts (electric motors, transformers, lighting, rechargeable batteries, control electronics). They can be contrasted with traditional mec ...
headquartered in
Andover, Massachusetts
Andover is a town in Essex County, Massachusetts, United States. It was settled in 1642 and incorporated in 1646."Andover" in '' The New Encyclopædia Britannica''. Chicago: Encyclopædia Britannica Inc.
An encyclopedia (American Engli ...
. Square D is a
flagship brand
A core product or flagship product is a company's primary promotion, service or product that can be purchased by a consumer. Core products may be integrated into finished product, end products, either by the company producing the core product or b ...
of
Schneider Electric
Schneider Electric SE is a French multinational company that specializes in digital automation and energy management. It addresses homes, buildings, data centers, infrastructure and industries, by combining energy technologies, real-time automation ...
, which acquired Square D in 1991.
The company was listed on the
New York Stock Exchange
The New York Stock Exchange (NYSE, nicknamed "The Big Board") is an American stock exchange in the Financial District of Lower Manhattan in New York City. It is by far the world's largest stock exchange by market capitalization of its listed ...
for 55 years prior to its acquisition without reporting financial loss in any calendar quarter, paying out 220 consecutive quarterly dividends to shareholders.
History

The company was founded on December 15, 1902 by Bryson Dexter Horton and James B. McCarthy. In 1903 they incorporated as the McBride Manufacturing Company. During the first decade of business, the company expanded into various other electrical products. In 1908, the company was renamed Detroit Fuse and Manufacturing. Horton, an 1895
electrical engineering graduate of the
University of Michigan
, mottoeng = "Arts, Knowledge, Truth"
, former_names = Catholepistemiad, or University of Michigania (1817–1821)
, budget = $10.3 billion (2021)
, endowment = $17 billion (2021)As o ...
, was credited with the invention of the safety switch, which encased high voltage switches and started the company's main line of business of circuit breakers and encased control panels. Their first enclosed safety switch was introduced in 1909.
Soon after their renaming to Detroit Fuse and Manufacturing, the company adopted their famous logo — a capital "
letter D" for
Detroit
Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at ...
, enclosed in a square. The logo was stamped on all Square D's switches and products. The combination of an easily remembered
monogram
A monogram is a motif made by overlapping or combining two or more letters or other graphemes to form one symbol. Monograms are often made by combining the initials of an individual or a company, used as recognizable symbols or logos. A series of ...
logo and their great popularity resulted in customers referring to their products as "Square D". Consequently, the company trademarked the logo and in 1917 they renamed the company Square D. Horton served as Square D's president until 1928
In the early 1920s Square D sold the majority of their
fuse
Fuse or FUSE may refer to:
Devices
* Fuse (electrical), a device used in electrical systems to protect against excessive current
** Fuse (automotive), a class of fuses for vehicles
* Fuse (hydraulic), a device used in hydraulic systems to prote ...
business in order to focus more on their safety switches and other safety products; advertisements with the tagline "Jones is Dead!" directed public attention to the lethal hazard of exposed electrical switches in factories. Square D hoped to capitalize on the growing concern of
factory safety.
By 1929, Square D merged with a Milwaukee-based industrial controller company and began producing
Westinghouse
Westinghouse may refer to:
Businesses Current companies
*Westinghouse Electric Corporation, the company that manages the Westinghouse brand, with licensees:
**Westinghouse Electric Company, providing nuclear power-related services
** Westingho ...
-licensed
circuit breaker
A circuit breaker is an electrical safety device designed to protect an electrical circuit from damage caused by an overcurrent or short circuit. Its basic function is to interrupt current flow to protect equipment and to prevent the risk ...
s. In 1935 Square D began producing its own range of circuit breakers for both commercial and residential uses.
In 1991, the company was acquired and became a subsidiary of
Schneider Electric
Schneider Electric SE is a French multinational company that specializes in digital automation and energy management. It addresses homes, buildings, data centers, infrastructure and industries, by combining energy technologies, real-time automation ...
.
In 2003, the Square D by Schneider Electric brand celebrated its 100th anniversary.
Today the company produces several lines of circuit breakers for domestic, commercial, and industrial applications.
Gallery
File:Square D plant in Detroit.png, The Square D plant on Rivard Street in Detroit
Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at ...
, 1920.
File:1917 square d enclose safety switch.png, A 1917 Square D enclosed 3-pole safety switch, utilizing cartridge fuses.
File:SquareD SafetySwitchAd JonesIsDead 1921.jpg, SquareD "Jones is Dead!" advertisement, 1921
File:Square D 20-Amp Double-Pole Breaker.JPG, A modern 20-ampere double-pole Square D circuit breaker
A circuit breaker is an electrical safety device designed to protect an electrical circuit from damage caused by an overcurrent or short circuit. Its basic function is to interrupt current flow to protect equipment and to prevent the risk ...
.
References
External links
{{Commons category, Square D
Square D products at Schneider Electric
Electrical wiring and construction supplies manufacturers
Companies based in Essex County, Massachusetts
History of Detroit
American companies established in 1902
Electronics companies established in 1902
Schneider Electric
1991 mergers and acquisitions
1917 establishments in Michigan