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ELECTRIC MOTOR CONTROLS 1 m- X. [1 |0 c9 L& G
% c3 m/ |% G2 E* pOnce the proper motor is selected, understanding the many various control devices available and + D W* R+ G; A2 A7 G1 Y$ ]+ b: Z1 I
their uses and limitations becomes an important part related to reliable operation and protection of
5 o6 f+ H! f# P5 B$ X4 Ethe motor and the personnel using the motor.
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3 Q6 C! [. v6 w! ?9 B& Y0 Y$ EMotor Control Topics
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There are four major motor control topics or categories to consider. Each of these has several
) [1 I: `( E( D$ e! Y' s& i csubcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
& p( W2 G4 \$ C5 T) A4 ^control equipment can accomplish multiple functions from each of the topics or categories.
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The four categories include: ( e7 g5 C3 K( t3 H3 f5 u
8 u" q& e) S1 a+ {1 G1) Starting the Motor
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, e% _2 s, F& M7 c, IDisconnecting Means
: c$ j( ?. b @; C4 ] _2 dAcross the Line Starting
, Q5 O4 |2 I9 M% ZReduced Voltage Starting
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; t- S! V2 T" l8 I6 b' o% _2) Motor Protection s. Y, Q& P0 l
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Overcurrent Protection + V! q4 K; y8 U' G2 F
Overload Protection
6 w' |; t3 d9 ZOther Protection (voltage, phase, etc) 8 c; p( ]# Y% ^( _8 b0 S, C
Environment $ U; ?; I5 o5 ?8 k' C
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7 m/ V6 j) ^9 I2 z7 Q3) Stopping the Motor
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Coasting
" R t2 \% b% x' {- Z) sElectrical Braking 2 O$ r/ Y& `7 _9 p: `5 V1 [ k
Mechanical Braking
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( n" a R; n! O7 k4) Motor Operational Control 6 B. @- W: o- g. a) c% O
/ c' P( B1 r+ Z6 b, p/ }6 H* c- }Speed Control 8 A; P- E& ?( I6 w9 X
Reversing
) G" }& K7 V# ?- ?Jogging
7 Q, \; j4 H( m- O) vSequence Control |
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