Product Manual

Hertz: Frequency, in cycles per second, of AC power; usually 60 hz in
North America, 50 hz in the rest of the world. Named after H. R. Hertz,
the German scientist who discovered electrical oscillations.
High Voltage Test: Application of a voltage greater than the working
voltage to test the adequacy of motor insulation; often referred to as
high potential test or “hi-pot.”
Horsepower: A measure of the rate of work. 33,000 pounds lifted one
foot in one minute, or 550 pounds lifted one foot in one second. Exactly
746 watts of electrical power equals one horsepower. Torque and RPM
may be used in relating to the horsepower of a motor. For fractional
horsepower motors, the following formula may be used.
HP = T (in.-oz) x 9.917 x N x 107
where,
HP = horsepower
T = Torque
N = revolutions per minute
Hysteresis: The lagging of magnetism in a magnetic metal, behind the
magnetizing flux which produces it.
IEC (International Electrotechnical Commission): The worldwide
organization that promotes international unification of standards or
norms. Its formal decisions on technical matters express, as nearly as
possible, an international consensus.
IGBT: Stands for isolated gate bipolar transistor. The most common
and fastest-acting semiconductor switch used in pulse width modulated
(PWM) AC drives.
Impedance: The total opposition in an electric circuit to the flow of an
alternating current. Expressed in ohms.
Induction Motor: The simplest and most rugged electric motor, it
consists of a wound stator and a rotor assembly. The AC induction motor
is named because the electric current flowing in its secondary member
(the rotor) is induced by the alternating current flowing in its primary mem-
ber (the stator). The power supply is connected only to the stator. The
combined electromagnetic effects of the two currents produce the force
to create rotation.
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