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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 3 x8 e$ F- [( F6 F8 F4 _- T: A
their uses and limitations becomes an important part related to reliable operation and protection of
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Motor Control Topics
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" `, \; h7 R# `There are four major motor control topics or categories to consider. Each of these has several 4 Z$ g' K; S1 R9 k" z+ C
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor 9 x% j! R* L9 ~6 l r. O+ x
control equipment can accomplish multiple functions from each of the topics or categories.
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L2 H8 r' H! b" E' X- F* }7 r# V7 FThe four categories include:
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1) Starting the Motor ' g5 L. f+ ]. O; a8 }
; X8 j: W! V' c+ I( L YDisconnecting Means 1 p. J7 X6 u5 F3 u& F" W9 n
Across the Line Starting $ u" m8 i) m# z/ u
Reduced Voltage Starting
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4 e+ l- s! A8 n. N4 A1 P2) Motor Protection
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" Q6 Z' X$ L* D) Y) Y( ?Overcurrent Protection
* V' k7 `4 K8 o' IOverload Protection . v, A. l, @5 B9 h! x) G6 q/ ?
Other Protection (voltage, phase, etc)
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0 C0 S6 {# A T' G- ^! n. ]4 {3) Stopping the Motor
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Coasting * ~5 C# c8 [/ D4 y0 {, [* P
Electrical Braking
4 I' G( k; P( e& P& |+ p c1 ~Mechanical Braking
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8 A I) c2 `2 r: T, t$ f) r4) Motor Operational Control , F( ~5 }8 A- u( t; i9 [7 E
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Speed Control
) F. s7 ~1 M* v/ K" iReversing
- G- m3 f( R' _& YJogging
" S2 W9 y% F2 ], Z! zSequence Control |
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