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ELECTRIC MOTOR CONTROLS k% y2 S5 H# ~& q9 y" G+ J) X
' v( X8 R/ @9 g$ \: GOnce the proper motor is selected, understanding the many various control devices available and
# Y5 Z! [ p5 B& f' Ptheir uses and limitations becomes an important part related to reliable operation and protection of ( L/ o+ W4 d. o- o
the motor and the personnel using the motor.
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/ }' d- ^% q( H0 F2 h- eMotor Control Topics
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There are four major motor control topics or categories to consider. Each of these has several
, v7 I7 ?0 B* s, ?+ w0 psubcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
1 `5 y4 O" e' n/ t# L, v. R5 p% {9 l( E9 p. mcontrol equipment can accomplish multiple functions from each of the topics or categories.
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$ ~& c, t# Y4 s9 }8 a9 xThe four categories include:
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1) Starting the Motor
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Disconnecting Means # ?3 e( I0 l' M+ c0 T! d$ `
Across the Line Starting + d7 F# `, g! F u h0 a& H
Reduced Voltage Starting
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2) Motor Protection
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Overcurrent Protection 0 V2 z- g$ Z) \* M. M
Overload Protection
k1 a0 d. P( eOther Protection (voltage, phase, etc) ; Q3 K8 d" h. ~
Environment
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3) Stopping the Motor $ Q( y0 v7 x% X
; N/ r0 n3 J5 m* C4 fCoasting
5 R; I" }/ W& @, J1 v5 aElectrical Braking
6 W1 ]; ~( w5 HMechanical Braking ' N# Z, _2 A& z6 c, [
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4) Motor Operational Control $ K9 A/ B9 v( C7 @
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Speed Control
- n; N3 d y" h: e, a) R2 EReversing
" t/ c5 o5 N# J" T3 Y4 eJogging
8 J6 v- J3 }+ B9 v/ B/ I4 ~Sequence Control |
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