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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
+ D6 C' ^( ~% }2 \; ztheir uses and limitations becomes an important part related to reliable operation and protection of : L# z: P1 N$ X4 V% b# | I/ [* d
the motor and the personnel using the motor.
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Motor Control Topics
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There are four major motor control topics or categories to consider. Each of these has several 7 K4 K& g% f6 D6 g
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
# y2 \$ w# T6 j7 ^& i# R% Ucontrol equipment can accomplish multiple functions from each of the topics or categories.
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) h$ Q$ p; o; a3 rThe four categories include: ! c- t9 E) a+ m: \
9 B" O/ L, e) e% E3 u3 P/ c2 I) K: U1) Starting the Motor
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/ g, F& ?: ^$ V% aDisconnecting Means $ f! i2 w8 c! k2 H7 R# a
Across the Line Starting
& A" P# F: ]+ b; XReduced Voltage Starting p2 C! M3 d; S* Q
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2) Motor Protection
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( E7 |3 i# N0 r8 H8 {! c: V* AOvercurrent Protection
, F* C6 P# ?; D9 J5 d3 O FOverload Protection % z: r$ j1 `' X h. L9 o
Other Protection (voltage, phase, etc)
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( O3 V% N; U* J. G0 K/ Q3) Stopping the Motor
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Coasting
1 d& \: F4 T+ u |: g/ T! o, ~Electrical Braking
( T X0 `+ J# U s1 vMechanical Braking
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9 `' F8 @- Z! m$ D! ?4) Motor Operational Control
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Speed Control 1 p2 u7 H% K- `) I& W) b! `
Reversing 7 Z: w- g- I1 w/ F
Jogging
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