Product Manual

Counter Electromotive Force: Voltage that opposes line voltage
caused by induced magnetic field in a motor armature or rotor.
Current, AC: The power supply usually available from the electric
utility company or alternators.
Current, DC: The power supply available from batteries, generators
(not alternators), or a rectified source used for special applications.
Duty Cycle: The relationship between the operating time and the
resting time of an electric motor. Motor ratings according to duty are:
• Continuous duty, the operation of loads for over one hour.
• Intermittent duty, the operation during alternate periods of load and
rest. Intermittent duty is usually expressed as 5 minutes, 30 minutes or
one hour.
Efficiency: A ratio of the input power compared to the output, usually
expressed as a percentage.
Enclosure: The term used to describe the motor housing. The most
common industrial types are: Open Drip Proof (ODP), Totally Enclosed
Fan Cooled (TEFC), Totally Enclosed Non-Ventilated (TENV), Totally
Enclosed Air Over (TEAO). (See Chapter IV for additional information).
Endshield: The part of a motor that houses the bearing supporting the
rotor and acts as a protective guard to the internal parts of the motor;
sometimes called endbell, endplate or end bracket.
Excitation: The act of creating magnetic lines of force from a motor
winding by applying voltage.
Explosion-Proof Motors: These motors meet Underwriters Laboratories
and Canadian Standards Association standards for use in hazardous
(explosive) locations, as indicated by the UL label affixed to the motor.
Locations are considered hazardous because the atmosphere does or
may contain gas, vapor, or dust in explosive quantities.
Field: The stationary part of a DC motor, commonly consisting of
permanent magnets. Sometimes used also to describe the stator of an
AC motor.
Flanged Reducer: Usually used to refer to a gear reducer having
provisions for close coupling of a motor either via a hollow (quill) shaft
or flexible coupling. Most often a NEMA C face motor is used.
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