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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 % |, y; j% x5 G- T8 R7 O6 B: M
their uses and limitations becomes an important part related to reliable operation and protection of
8 D5 @: p( V1 t" y3 C8 X7 cthe motor and the personnel using the motor. 0 _) e6 y; z k9 n. Z$ f( l
) I$ j8 q5 [3 m, M; v1 a( N( pMotor Control Topics : B/ V, j1 U) o; W4 L1 ?1 M @
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There are four major motor control topics or categories to consider. Each of these has several 5 v0 ]2 T7 p( D0 I; Q4 @
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
( u6 z! K0 j% Q1 l Icontrol equipment can accomplish multiple functions from each of the topics or categories. 1 U' s- z; r: `, @
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The four categories include:
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0 h6 l" y8 F5 E6 d6 d9 J1 Y: I* N1) Starting the Motor
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Disconnecting Means & {2 z1 `5 a8 v0 Y g& C& l7 m
Across the Line Starting
7 o# e3 t: C, y! h* xReduced Voltage Starting 9 z) e, E( E( e# A8 w* ]! \0 q; T1 `4 `
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. e1 e) C9 i5 e6 z. w# ]) V2) Motor Protection ' _: T% ~: P$ w: a8 p
7 ^( e$ Q; s& O/ MOvercurrent Protection
$ [0 t2 P# |- ROverload Protection
8 e6 Q! @; o; v( F! a0 A* G9 mOther Protection (voltage, phase, etc) + o7 O9 |4 M$ |+ r
Environment # m8 _9 q+ j& v% \/ s$ u
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, t. W; T; f- C- O4 _+ d! S3) Stopping the Motor
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Coasting # D5 k C* ]& x* Q
Electrical Braking
( J4 @1 I4 R5 e; d$ l F \3 UMechanical Braking
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4) Motor Operational Control 4 ]3 O; I5 T, k
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Speed Control + X$ G0 E+ d5 q X* z
Reversing
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Sequence Control |
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