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ELECTRIC MOTOR CONTROLS ! ~; ?, h% ~1 n7 @* ~
9 B. ^5 f, Z) cOnce the proper motor is selected, understanding the many various control devices available and
4 |# ?' Q! o6 p4 _! u& }their uses and limitations becomes an important part related to reliable operation and protection of - j& h/ f! H6 } E7 f
the motor and the personnel using the motor.
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Motor Control Topics % T6 {4 W4 v2 W( g
, E6 q5 D: @, d* H. ^9 lThere are four major motor control topics or categories to consider. Each of these has several 9 N) Q& l, e/ I" B' a! x
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
4 ~) Y9 M# U1 Scontrol equipment can accomplish multiple functions from each of the topics or categories.
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* g/ l! R/ f5 b) T: YThe four categories include:
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3 ]4 T* p% |6 ~5 H9 V2 S' ]1) Starting the Motor
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+ X+ C5 K( F' Q, Q8 W0 bDisconnecting Means
# L- t3 @9 e8 hAcross the Line Starting ! \ W# b+ v) d( L ]8 i
Reduced Voltage Starting
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2) Motor Protection ! B! u7 ?. P6 y( `, ~* _$ A# o
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Overcurrent Protection
' `- n+ R$ H; R/ jOverload Protection ~8 L8 t. j& a- F' i6 U. p
Other Protection (voltage, phase, etc) ' c) @" w# H2 ^) G6 Y" D" W
Environment
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8 @% v. K+ X7 `3) Stopping the Motor
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Coasting
/ l W" n; N8 f% C8 X) tElectrical Braking 4 j; {% K; |5 ?& R3 ?5 M! g
Mechanical Braking ( a" x' O3 I2 q& f
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4) Motor Operational Control 4 d* d) _; N5 i
* p- v' c2 r7 u* {7 zSpeed Control
$ P4 O0 O8 h; r5 H5 N0 C& `Reversing / f+ L1 S( [! w& J" b
Jogging / a* n$ e9 U* `+ z
Sequence Control |
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