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ELECTRIC MOTOR CONTROLS 4 A/ u. C/ J0 T% s
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Once the proper motor is selected, understanding the many various control devices available and
5 w7 C, Z( R1 S" Ftheir uses and limitations becomes an important part related to reliable operation and protection of 9 O. S; V: ]6 E0 s
the motor and the personnel using the motor.
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Motor Control Topics , s$ S9 X$ |- I1 F
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There are four major motor control topics or categories to consider. Each of these has several
8 l: k, X) ~( p# X) Fsubcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
. a4 M( q( W( n0 e3 Bcontrol equipment can accomplish multiple functions from each of the topics or categories. 5 y% d$ P" b/ f# T- b: L" f! B
/ \9 g) q6 t5 w% k$ Q" r8 `! IThe four categories include:
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) r( m$ R; K) o& z# d8 T1) Starting the Motor 9 o0 q9 e! F; d1 u* e
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Disconnecting Means 8 r6 W" w- H/ Y8 m2 `- f
Across the Line Starting 0 S- h4 k2 H k/ ~8 z/ l
Reduced Voltage Starting
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2) Motor Protection
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Overcurrent Protection
4 G* G- V( m2 b9 U- z" oOverload Protection
c# `) I. ^2 v& m- {4 v( {2 ^Other Protection (voltage, phase, etc) 8 J% K3 z! C' k; e
Environment
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3) Stopping the Motor
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) P& Y& a7 I: q/ K# @Coasting O& T1 o# [/ h' S7 ^4 O
Electrical Braking
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C( T: x) J5 s4) Motor Operational Control 3 m6 x& Z k, B# i- f0 i
% B& p- Y: K {! _ g. T' j2 xSpeed Control / C. b r7 a; J: l% h8 Y+ A1 C) D
Reversing
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8 B& K- X( ~6 e, iSequence Control |
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