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ELECTRIC MOTOR CONTROLS
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2 b, @. {% q# cOnce the proper motor is selected, understanding the many various control devices available and
' Y& H# D7 h& e/ w+ w% }their uses and limitations becomes an important part related to reliable operation and protection of " I! q% f/ T% g
the motor and the personnel using the motor.
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* v- n( _9 a; `6 @% x* fMotor Control Topics
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4 @# }2 B3 ^. S3 c& q! |% p( GThere are four major motor control topics or categories to consider. Each of these has several - ~" D- q6 C# s( G1 \) B* o8 l, T
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
6 O4 O: x/ m1 X! Hcontrol equipment can accomplish multiple functions from each of the topics or categories. : Q; S- e7 |" h. d; z, t7 Y
5 x! N& F, T7 {0 s( n0 S- ?8 l" |The four categories include: ' r+ b$ u9 e4 x1 g6 ?
) A0 K9 k* O" m, N/ j1) Starting the Motor
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( D$ ?4 R5 z7 I4 C3 p u: C; H; tDisconnecting Means , U- u- F4 O+ o+ W$ M
Across the Line Starting 1 \' H* M5 F) b/ [
Reduced Voltage Starting , f' l6 M Z! a. }
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% P" I# h/ s( m- W& m9 s$ q2) Motor Protection 8 s1 {: T3 ]! z' F3 y0 L
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Overcurrent Protection 0 L0 F2 _5 r( ^ H# F9 V
Overload Protection * t# A9 q& s0 W6 y4 d0 z2 l ]
Other Protection (voltage, phase, etc)
! X! ]* ^3 f3 h6 Y$ g5 \Environment
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% y$ V6 N) M K3) Stopping the Motor 8 d! ]2 `) c- r# A6 u8 _
) ]" C$ t6 u3 R- V. V6 y/ U7 ?Coasting " ~- H M- w2 I1 x1 u) h- @' @
Electrical Braking # y' n1 @1 W( q w% ?
Mechanical Braking
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4) Motor Operational Control
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Speed Control
9 J* o0 q# N. n; o, x- Y% dReversing
3 _6 t. q* s* {" t' S7 ]4 G- HJogging 6 _ B: ~! ~& b4 G6 G
Sequence Control |
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