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ELECTRIC MOTOR CONTROLS ' S/ @: x$ L8 T& e
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Once the proper motor is selected, understanding the many various control devices available and 6 G3 K: O/ Q8 k0 x
their uses and limitations becomes an important part related to reliable operation and protection of
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" s. _0 m& O& F9 v) y8 p2 x3 pMotor Control Topics " Z8 Q" c9 _4 L
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There are four major motor control topics or categories to consider. Each of these has several ! G$ b6 |$ m7 f- i" `
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
0 r7 a% U- N# m8 h0 r- pcontrol equipment can accomplish multiple functions from each of the topics or categories.
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The four categories include: * W, ]7 h( y2 ^) y \% f) a& O
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1) Starting the Motor
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Disconnecting Means
9 B$ x o: H9 S7 }Across the Line Starting
- l: S4 l5 T3 N' ^9 ?7 ZReduced Voltage Starting
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2) Motor Protection " }4 A8 P7 _( v7 X& d' l
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Overcurrent Protection
. i+ N% ^$ r, _; R: J0 @1 r' NOverload Protection ; I3 H$ j/ a' K, L6 x# q; z, M
Other Protection (voltage, phase, etc) * ~. @5 W# H2 B% `& u/ a
Environment ' ^1 M O% ~5 C! J
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3) Stopping the Motor " |9 z& T* N! b# T; B* q
^/ s5 u0 L8 X2 O! _! XCoasting
4 i3 H% c K. F0 A# @$ F: g. @Electrical Braking " ^& F, v# Q7 e( s7 m" d9 Z; v
Mechanical Braking 4 \1 `9 ?* b3 v# e# }" o; U" Q# t
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4) Motor Operational Control , X! ^0 @& L) P7 W9 y& B% Z
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Speed Control
/ e' t& F7 s7 `8 D, }( ~Reversing
. q4 n* V3 H5 `" G! V4 `Jogging
1 O. F) g% m% _4 u4 A2 ]- D! TSequence Control |
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