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ELECTRIC MOTOR CONTROLS
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- E2 v; ?+ s. N/ X: l# {Once the proper motor is selected, understanding the many various control devices available and * b% O4 E& Z, d' n
their uses and limitations becomes an important part related to reliable operation and protection of ) L4 A- u7 Y9 P; M6 }: h7 c
the motor and the personnel using the motor.
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, |" f! E: X# e& X4 lMotor Control Topics , e6 B; G0 n) `! u& h3 y. ^
4 y* K4 H5 m' [, b; `" PThere are four major motor control topics or categories to consider. Each of these has several * T1 m9 K) f+ w B: r
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
) G2 D+ A7 S# Q* I& ncontrol equipment can accomplish multiple functions from each of the topics or categories.
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: e O, ~3 I/ k4 l* |/ OThe four categories include:
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, k( h. V, Y3 m) ?" G1) Starting the Motor * a C5 {/ J* y0 B: e( {3 S
8 L( y& C+ n* f& qDisconnecting Means : y& {" M; C6 g. D+ A0 _. s8 l
Across the Line Starting
( y+ A7 x2 F( l; ~( BReduced Voltage Starting 7 n' c0 u; Q% w/ H5 J
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+ J3 e, u4 b% A2) Motor Protection ( U4 N- |9 h* S6 @* z( q9 Z5 N
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Overcurrent Protection . Q: k/ h5 T, `+ K2 J
Overload Protection , ~$ }9 Z' B3 g$ g5 r% }' p8 Y! M
Other Protection (voltage, phase, etc) ; N6 b1 E( h7 @8 X
Environment
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' R* |8 T* D/ Q3) Stopping the Motor - v X2 d: M+ `/ B5 ?$ [
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Coasting 1 z( V% a/ ~) d" T# K5 i
Electrical Braking
7 V2 H1 r0 R1 w4 }& hMechanical Braking ; ]4 a, l) H/ {' c0 E% j. I
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4) Motor Operational Control
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- i4 ?# h8 [& `! g1 {/ gSpeed Control 6 G. d5 i; w1 w3 v0 K1 K
Reversing 8 ^$ O% _! @, y1 l% O
Jogging b1 ^+ u4 e# p! ^
Sequence Control |
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