This designation shows that a product such as a motor or
control meets European Standards for safety and environmental protection. A CE mark is required for products used in
most European countries.
CIV (CORONA INCEPTION VOLTAGE)
The minimum voltage amount that begins the process of ionization
(corona) of motor windings.
Canadian Standards Association like U.L., sets specific standards
for products used in Canada.
A type of flange used with close-coupled pumps, speed reducers
and similar equipment where the mounting holes in the flange are threaded to
receive bolts. Normally the “C” flange
is used where a pump or similar item is to be connected on the motor.
The “C” type flange is a NEMA standard design and available with or without
feet.
A protective cover placed on the top of a motor being mounted
vertically to protect it from liquids or solids that might drop onto the motor
(functions as an umbrella for the motor).
A device which, when connected in an alternating-current circuit,
causes the current to lead the voltage in time phase. The peak of the current wave is reached ahead
of the peak of the voltage wave. This
is the result of the successive storage and discharge of electric energy used
in single-phase motors to start, or in three phase motors for power factor correction.
A single-phase induction motor with a main winding arranged
for direct connection to the power source, and an auxiliary winding connected
in series with a capacitor. There are
three types of capacitor motors: capacitor
start, in which the capacitor phase is in the circuit only during starting;
permanent-split capacitor, which has the same capacitor and capacitor phase
in the circuit for both starting and running; two-value capacitor motor, in
which there are different values of capacitance for starting and running.
The capacitor start single-phase motor is basically the same
as the split phase start, except that it has a capacitor in series with the
starting winding. The addition of the
capacitor provides better phase relation and results in greater starting torque
with much less power input. As in the
case of the split phase motor, this type can be reversed at rest, but not while
running unless special starting and reversing switches are used. When properly equipped for reversing while
running, the motor is much more suitable for this service than the split phase
start since it provides greater ability at less watts input.
A centrifugally operated automatic mechanism used in conjunction
with split phase and other types of single-phase induction motors. Centrifugal cutout switches will open or disconnect
the starting winding when the rotor has reached a predetermined speed and reconnect
it when the motor speed falls below it. Without such a device, the starting winding
would be susceptible to rapid overheating and subsequent burnout.
A mechanical device for engaging and disengaging a motor.
It is often used when many starts and stops are required.
A term used to describe non-uniform and angular velocity.
It refers to rotation occurring in jerks or increments rather than smooth
motion. When an armature coil enters the magnetic field produced by the
field coils, it tends to speed up and slow down when leaving it. This effect becomes apparent at low speeds.
The fewer the number of coils, the more noticeable it can be.
The electrical conductors wound into the core slot, electrically
insulated from the iron core. These
coils are connected into circuits or windings, which carry independent current.
It is these coils that carry and produce the magnetic field when the
current passes through them. There are
two major types: “Mush” or “random” wound, round wire found
in smaller and medium motors where coils are randomly laid in slot of stator
core; and formed coils of square wire individually laid in, one on top of the
other, to give an evenly stacked layered appearance.
A cylindrical device mounted on the armature shaft and consisting
of a number of wedge-shaped copper segments arranged around the shaft (insulated
from it and each other). The motor brushes
ride on the periphery of the commutator and electrically connect and switch
the armature coils to the power source.
Designed with both a series and shunt field winding, the compound motor is used where the primary load requirement is heavy starting torque and variable speed is not required. Also used for parallel operation. The load must tolerate a speed variation from full load to no-load.
Industrial machine applications include large planers, boring
mills, punch presses, elevators and small hoists.
A material such as copper or aluminum which offers low resistance
or opposition to the flow of electric current.
The metal container usually on the side of the motor where
the stator (winding) leads are attached to leads going to the power supply.
A designation for variable speed motors used for loads requiring
the same amount of horsepower regardless of their motor speed during normal
operation.
Refers to loads with horsepower requirements that change linearly
at different speeds. Horsepower varies
with the speed, i.e., 2/1 HP at 1800/900 RPM (seen on some two-speed motors).
Applications include conveyors, some crushers and constant-displacement
pumps.
A DC motor which changes speed only slightly from a no-load
to a full-load condition. For AC motors,
these are synchronous motors.
The iron portion of the stator and rotor made up of cylindrical
laminated electric steel. The stator
and rotor cores are concentric and separated by an air gap, with the rotor core
being the smaller of the two and inside to the stator core.
This is the electrical discharge breakdown of a winding through
the application of excessive voltage.
COUNTER ELECTROMOTIVE FORCE (CEMF)
The induced voltage in a motor armature caused by conductors
moving through or “cutting” field magnetic flux. This induced voltage opposes the armature current and tends to reduce
it.
The mechanical connector joining the motor shaft to the equipment
to be driven.
This time rate of flow of electrical charge and is measured
in amps (amperes).
One complete reverse of flow of alternating current per rate
of time. (A measure of frequency.) 60 Hz (cycles per second) AC power is common
throughout the US and 50 Hz is common in many foreign countries.