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ELECTRIC MOTOR CONTROLS {( w) Z8 |$ A
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Once the proper motor is selected, understanding the many various control devices available and 5 \8 z6 H% I. H \
their uses and limitations becomes an important part related to reliable operation and protection of ; j9 C4 ?' y9 w
the motor and the personnel using the motor.
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, G: x& r/ `2 x7 S: {Motor Control Topics
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There are four major motor control topics or categories to consider. Each of these has several 6 G3 n' f+ V; W& W4 C& b3 D+ g
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
& h4 N5 x! l5 h) `9 t, S4 Rcontrol equipment can accomplish multiple functions from each of the topics or categories.
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The four categories include: ( G: ?1 [, |) _7 S
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1) Starting the Motor
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5 v* o- `% ]9 d% r9 QDisconnecting Means P; g7 c9 B) I
Across the Line Starting
) Y; d3 o, x# R; ~Reduced Voltage Starting
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3 u7 K4 T' F1 i Y2) Motor Protection 5 \3 i1 C; ^+ Z6 M; I" T
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Overcurrent Protection
7 l5 Q, o. J8 ~' C5 SOverload Protection
+ T l& D* l4 ~Other Protection (voltage, phase, etc) ' F2 C1 M+ N# i8 e9 Q
Environment
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3) Stopping the Motor
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Coasting 6 A% X# i6 d. \* o
Electrical Braking & w1 A! `! k: F# C+ \0 @# W
Mechanical Braking
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4) Motor Operational Control 8 H8 x# N: s1 W7 D/ ?+ c0 p
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Speed Control
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Jogging 4 ^! D9 i( [! z' L2 l
Sequence Control |
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