Specifications

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Trip Unit The part of the circuit breaker that determines when the
breaker will trip. Many circuit breakers use a thermal-magnetic
or magnetic-only trip unit. Other circuit breakers have a solid-
state trip unit with multiple adjustments to custom fit the circuit
breaker’s time current curve to the application.
Solid State Breaker
Solid State
Tripping Unit
Trip
Signal
Magnetic
Latch
Breaker
Mechanism
Protected
Circuit
Power
Source
Current
Sensors
True Power Also called real power, true power is the power dissipated by
circuit resistance. True power is equal to I
2
R and is measured in
watts. True power is also equal to the apparent power multiplied
by the power factor.
Sonar Proximity Switch A type of sensing switch that uses high frequency sound to
detect the presence of an object without coming into contact
with the object. Sometimes referred to an an ultrasonic
proximity switch.
Target
Emitted Pulse
Echo
Sonar
Proximity
Switch
Underwriters Laboratories An independent product safety certification organization,
(UL) Underwriters Laboratories, Inc. develops standards and tests
products for safety. Products that pass UL tests can carry a UL
mark. UL has several categories of marks based upon the type of
product tested.
Var The basic unit for reactive power. Shortened from volt-ampere
reactive.
Variable Frequency Drive An electronic device used to control the speed a of an AC
(VFD) motor. A VFD controls the motor speed by varying the frequency
and voltage applied to the motor. Also called an AC drive.