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.
