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ELECTRIC MOTOR CONTROLS
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7 A5 B! |7 `1 eOnce the proper motor is selected, understanding the many various control devices available and : N6 n4 z+ P9 K
their uses and limitations becomes an important part related to reliable operation and protection of 2 C' {8 q# x: H$ |+ D, S8 i* T
the motor and the personnel using the motor. & z+ G# D/ m. u. b0 z
2 F! W0 ]9 z; I- H4 o) `% vMotor Control Topics
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" L A# w) p% o+ _. I1 rThere are four major motor control topics or categories to consider. Each of these has several # p' h9 {3 m" C" l; n
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
" u/ p S3 @, L* |; Rcontrol equipment can accomplish multiple functions from each of the topics or categories. ( d$ s8 |9 n4 `2 G6 ]
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The four categories include: % B/ i9 t1 S. \$ }( ~# c5 k
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1) Starting the Motor
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`' {* p# J* a' ?' r$ q" gDisconnecting Means
$ U o& N6 P/ q: u$ U& nAcross the Line Starting ; N6 a, f/ ]" ?5 v# @% R0 e' S
Reduced Voltage Starting
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& T0 q ]$ K* e( L: p* V2) Motor Protection ; V0 o9 {$ ~& v" F) `
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Overcurrent Protection ! Z$ q: G' v( O3 U7 U
Overload Protection % r5 [ B0 a- s% C5 Z
Other Protection (voltage, phase, etc)
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- v: W6 f+ m: h3) Stopping the Motor & f* G! m! K, @: @3 s& Z* Q
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Coasting
* ~$ t/ f$ U6 rElectrical Braking ) ^% {( N! L. N# s& q7 D( ^
Mechanical Braking 6 w1 e# s: `6 `
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9 j% V ]# t8 M4 `- i2 m) c4) Motor Operational Control
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Speed Control
/ b4 |8 t0 z8 tReversing
* q* B+ @8 R% E: u4 D: XJogging 6 k- y g' H5 r0 Z* a; _9 n
Sequence Control |
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