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ELECTRIC MOTOR CONTROLS
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! ~' T9 R+ c3 p% {& @* _Once the proper motor is selected, understanding the many various control devices available and
2 {) ^3 @2 r# |1 [. P, Atheir uses and limitations becomes an important part related to reliable operation and protection of
3 k, `" f Q5 ]; D. [' G7 pthe motor and the personnel using the motor. : F- `, C9 j/ p6 f& ~. a
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Motor Control Topics ' m' Q5 k$ }6 s6 v( x1 ]
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There are four major motor control topics or categories to consider. Each of these has several
0 L7 p7 j1 M5 Hsubcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor 7 c' P, s% T( e- C; L% x9 s
control equipment can accomplish multiple functions from each of the topics or categories. $ |$ t& s7 y. k$ V+ ]# t
y% `; s# Y5 _' MThe four categories include:
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1) Starting the Motor
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' {1 F2 K5 @# ~( {. TDisconnecting Means 9 U0 t% W9 o, P+ W3 ]
Across the Line Starting
# @% x; o5 j3 V: W) lReduced Voltage Starting
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y! R: x( u/ w d+ @* x2 J4 e2) Motor Protection 1 i0 L3 I" u3 o3 ]1 ^% C
+ a l" R% K5 }Overcurrent Protection A! \! ]; {( H4 Q; h3 n
Overload Protection
# e n: @( c" W- Q8 J3 A- QOther Protection (voltage, phase, etc) ! ]( ^3 d& a3 M. k7 m7 Q
Environment
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3) Stopping the Motor
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Coasting : N I8 I. Q/ x9 O8 A
Electrical Braking ) i& A( S1 L6 g' ~5 p
Mechanical Braking
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6 f9 |7 ?# K; Q- I4) Motor Operational Control
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" z4 M; t, ^8 r. S/ v) OSpeed Control % T) i+ w+ X, F- J# j& M
Reversing . I6 O7 |9 [. _7 R8 M* [% `1 ^
Jogging 3 D/ M2 W8 e3 L2 C; j
Sequence Control |
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