Historic Philadelphia

Product developments and improvements
throughout the company’s history have led to its
current line of information systems, computerintegrated
industrial automation systems, defense
systems, instruments systems, semiconductors,
and other electronic components.
It is a far cry from Cutter’s double-push wall
switch and the first circuit breaker. The original
circuit breaker, which was attached to the wall,
looked like a black box of iron bars. It operated
with a shunt fuse for interruption. With a
principle of inverse time element, it opened the
circuit fastest when the greatest overload
occurred. After its development in 1890, most
air circuit breakers used this principle.
Acquiring a small factory in downtown
Philadelphia, Harrington and Cutter, soon joined
by William M. Scott and A. Edward Nelson,
began manufacturing the circuit breaker. They
continued to refine the design, and by 1905,
extended the principle to the direct acting limit
inverse time element (Dalite) for low-voltage air
circuit breakers. In 1908, the company acquired
a switchboard manufacturer, Walker Electric
Company, to add switchboards to Cutter’s line.
Numerous businesses were acquired from
1940 to the 1960s, and many products were
added and developed. The company grew to
become a full-line supplier of electrical power
distribution equipment ranging from 120 to
600,000 volts. A 1967 merger with Imperial
Eastman added fluid power control to the
I-T-E Imperial Corporation. Nine years later,
I-T-E Imperial merged with Gould, Inc. After
divestiture of two of the original I-T-E Imperial
divisions, Gould formed the Systems Protection
Division in Philadelphia, the company’s first
complete and separate business entity
responsible for its Navy products.
L-3 Communications, headquartered in New
York City, merged with SPD and its subsidiaries
in 1998. L-3 is a leading merchant supplier of
secure communications systems and products,
avionics and ocean systems, microwave
components and telemetry, instrumentation,
space and wireless products. Its customers
include the Department of Defense, select U.S.
government intelligence agencies, foreign
governments, aerospace and defense prime
contractors, and commercial telecommunications
and cellular companies.
✧
Top: SPD’s Actron Air Circuit Breaker ACB-
1606HRC was developed for Naval
applications. These air circuit breakers are
available in ratings from 600 amperes to
4,000 amperes, and offer state monitoring
of the electric system, which it protects.
State monitoring provides information on
ground faults, type and phase of last trip,
phase current, current data logging, and
functions such as bi-directional
communication and remote opening and
closing of the circuit breaker.
Middle: SPD’s Actron Molded Case Circuit
Breaker AQB-LF252 developed for naval
applications. These molded case circuit
breakers are available in ratings from 15
ampere to 1,600 ampere, and offer state
monitoring of the electric system which it
protects. State monitoring provides
information on ground faults, type and
phase of last trip, phase current, current
data logging, and functions such as bidirectional
communication and remote
opening and closing of the circuit breaker.
Bottom: SPD’s High Speed Circuit Breaker
has been specifically designed for use on a
variety of mass transit vehicles including
subway, commuter, and light rail systems. A
circuit breaker for use on Direct Current
applications, it is capable of over current
protection on the full range of system
voltages now in common use (600-3,000V
DC) and for currents up to 5,000 amps.
INDUSTRY &
MANUFACTURING
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