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ELECTRIC MOTOR CONTROLS ( U( d+ J" U& |. m: t- c0 e
2 X& L- }+ q7 ]( F) S* VOnce the proper motor is selected, understanding the many various control devices available and ( {- f$ r* W* \1 {5 Q" |4 E
their uses and limitations becomes an important part related to reliable operation and protection of ) Z6 L! ]! b8 D) w7 ?& t; i% c7 R
the motor and the personnel using the motor. 6 b1 s8 o+ Z0 r+ q% d' T
) v5 h, w( ?% MMotor Control Topics
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; M# j% i3 e4 }0 i) H2 jThere are four major motor control topics or categories to consider. Each of these has several
0 q% I1 b8 P1 F# k+ osubcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
& A. l" u4 Q3 y( w! P3 \$ xcontrol equipment can accomplish multiple functions from each of the topics or categories.
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/ z8 Q6 o9 I# U: f$ v* oThe four categories include:
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: g; `, m& g# K5 F: a4 \. [1) Starting the Motor
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+ w; G/ U, u Q: d* LDisconnecting Means
1 `$ S3 N7 v+ ]" ? j) mAcross the Line Starting 8 I( i% i; U! `4 K- o
Reduced Voltage Starting ) y b( [$ R0 c+ [# r
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2) Motor Protection 8 x* j: T% R/ {/ s0 W& m8 S6 u
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Overcurrent Protection * a" ^# f1 b- R6 m% O
Overload Protection 5 }# d* @: d. B, w0 ?
Other Protection (voltage, phase, etc) % Y5 @! {8 T9 h( V
Environment
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$ y7 T( @* i: h& B3) Stopping the Motor 2 S( `/ c7 h" j* u! o9 r' k
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Coasting
8 `. c8 o. ?9 o: W7 c; J# j V# hElectrical Braking
9 R- |6 M! I! q; |: y# g) ]. dMechanical Braking
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4) Motor Operational Control 2 O% x# ^! v) G
) \* z( U# z4 p- xSpeed Control
M: R7 e6 v$ K0 d1 K/ sReversing
V$ s# S9 c2 p |/ a4 tJogging ( _/ t7 L' x% h
Sequence Control |
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