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ELECTRIC MOTOR CONTROLS
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Once the proper motor is selected, understanding the many various control devices available and 4 F& h7 H( ~4 H6 Z' G+ r7 v
their uses and limitations becomes an important part related to reliable operation and protection of ( w* W6 L9 r$ P a
the motor and the personnel using the motor.
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Motor Control Topics
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There are four major motor control topics or categories to consider. Each of these has several 5 h2 m$ {( F' Q5 @$ d
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor ; a, T" O& J8 ^2 Y( m: f5 f
control equipment can accomplish multiple functions from each of the topics or categories.
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The four categories include: 9 Y. ~6 W( K. V p
5 ]$ b' P+ d: ]8 h1) Starting the Motor
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Disconnecting Means + r: W" [% d$ k1 n+ k& L( D
Across the Line Starting
( T2 a B- l& F) b1 c- mReduced Voltage Starting - k9 S" K0 a b% E6 Y4 K
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0 h$ y7 M. a5 T0 F( r, d2 j- c w2) Motor Protection 7 M- X% Y8 h( r: \$ V! j
. B' w" G, N; G% w/ f' J2 eOvercurrent Protection
3 d7 K) P' q$ w* iOverload Protection 9 n" L: _# j0 r" U& e c6 S6 Y
Other Protection (voltage, phase, etc)
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3) Stopping the Motor
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' L( ^" J0 a# I0 PCoasting
$ L& |. ^) t! q9 p* _' \Electrical Braking
]9 T% B7 g4 i9 e, _5 l% jMechanical Braking , g8 W$ t3 j3 S, p7 S Q
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. \$ H9 ]. p! n! P2 A, @- S' z8 f4) Motor Operational Control
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Speed Control - ]0 U- n. @$ p2 N3 d
Reversing 1 k Y" h! A1 h! W, @7 a
Jogging F; R3 |' n ]3 ]( F
Sequence Control |
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