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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
7 W& B/ E1 u% w. N5 _# Q5 Q) vtheir uses and limitations becomes an important part related to reliable operation and protection of , u: S6 C8 y d" f# G% y7 @
the motor and the personnel using the motor. ' i9 j1 O& ^9 [8 p& i# w! }
% x# M4 b5 w8 @Motor Control Topics
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There are four major motor control topics or categories to consider. Each of these has several
. U& I: H) {% X& X% d( @subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor , S! K! H( v; r( H' Y8 x
control equipment can accomplish multiple functions from each of the topics or categories. 0 ], ^8 N/ M" {; y$ t2 a7 C! t
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The four categories include: 6 ~; Z, D2 f T) s7 X
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1) Starting the Motor . K$ @6 ]8 w: _* H( \8 N* ?4 d% o
! D9 G: x" a W4 ^Disconnecting Means
7 e1 L$ c7 k7 q( O( Y* ]Across the Line Starting
% k! E( Z* ] sReduced Voltage Starting 7 {9 L% |" k# u! y+ c: J* y( |
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. G0 \& y( b, g) O2) Motor Protection
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Overcurrent Protection
' O4 j$ B0 S( L* Y+ [, DOverload Protection 3 [% u# t; u4 c
Other Protection (voltage, phase, etc)
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3) Stopping the Motor 3 r3 s5 p5 g. `6 o
" P1 p' c* K4 O4 @/ tCoasting y" L( X/ n+ _4 g9 J$ U3 H
Electrical Braking ! t! c7 k5 X* y" q) E+ m" R
Mechanical Braking + ?' \7 S/ M: \1 B+ g
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9 Y7 M7 ]" T* {4) Motor Operational Control ) Z( D; o H! b4 G* }( h+ P4 e
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Speed Control " L( a- Y6 j, T |
Reversing
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Sequence Control |
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