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ELECTRIC MOTOR CONTROLS 6 U8 o- w+ v& M* Y
6 H$ R( m! z8 x3 d$ U9 V! Z/ _Once the proper motor is selected, understanding the many various control devices available and 6 g! K0 C0 q5 F" k
their uses and limitations becomes an important part related to reliable operation and protection of ! Y5 |! J3 D4 F, H+ J/ M: J7 I
the motor and the personnel using the motor. 0 q: y" T- s6 V7 N
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Motor Control Topics $ i- L; S: k+ ]6 d" |% Y: e! K
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There are four major motor control topics or categories to consider. Each of these has several
; `( h) |- R; @* Asubcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
: Y n: G* i' A1 ycontrol equipment can accomplish multiple functions from each of the topics or categories.
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The four categories include: ! A2 X" b+ E: a, a
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1) Starting the Motor 0 r5 I8 B, i" y7 a3 o
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Disconnecting Means
, n9 r1 [) R" [* q2 ^$ O2 U9 Q& GAcross the Line Starting 5 w3 E3 r7 ?+ @1 _- e5 U9 b
Reduced Voltage Starting
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2) Motor Protection
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Overcurrent Protection
0 j" i2 k& w& ?" Q9 ^Overload Protection
# s& }1 X+ m# m: S: c/ w, j5 h; \Other Protection (voltage, phase, etc)
9 j7 w" U6 h: D' k4 EEnvironment
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$ M8 p8 W# D f4 `3) Stopping the Motor
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Coasting : ]4 z! z' N, R6 I: ~5 g2 e
Electrical Braking
% N, b7 i. J. x4 RMechanical Braking ( G9 X; s# [/ b1 C% C8 c* U5 y
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4) Motor Operational Control
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Speed Control
! J" l3 R6 k- n8 y4 iReversing
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Sequence Control |
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