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ELECTRIC MOTOR CONTROLS 7 G/ [$ @; h8 W( o8 G) m
0 f* g) |( k/ P6 t5 SOnce the proper motor is selected, understanding the many various control devices available and 1 ]& z( X2 p( p0 b2 p) d B
their uses and limitations becomes an important part related to reliable operation and protection of 5 |! h. `; P+ C) J, P) Z+ u
the motor and the personnel using the motor. 2 y$ ]3 V% @! t% A2 B% ^
. B: I1 k9 U" `Motor Control Topics
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There are four major motor control topics or categories to consider. Each of these has several ! ~* s* r3 U5 I
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor 9 ~2 Y/ f1 W+ \
control equipment can accomplish multiple functions from each of the topics or categories. , }7 t2 C$ S$ [6 U7 C% ~
* L$ X) ~& ^- ~5 |6 \% U8 LThe four categories include:
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( ]+ K6 o1 Y+ w# N1) Starting the Motor
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$ @' }7 l4 y% o: `# SDisconnecting Means ' x+ x+ H8 }6 D, v* c( G7 ?0 x
Across the Line Starting
' w1 f4 D$ m q! X. U1 s4 C _. XReduced Voltage Starting % r" K# P* U# _4 g9 q( L5 L
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6 n( r+ I/ ?: l$ p0 t( ^2) Motor Protection 0 }( [0 c- o" m. l
8 S5 [- u1 K& Z8 zOvercurrent Protection ) r7 D4 Y' C1 }
Overload Protection
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Environment , [% z2 e0 c" x @. u# a+ H$ M1 u
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3) Stopping the Motor 1 J6 |7 l4 {: E7 y3 k L7 v4 M9 k
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Coasting
9 `5 W" \% u, R0 n% P; f: N& KElectrical Braking 3 u2 s9 `: E* c1 X, d; e7 U
Mechanical Braking
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: f# j8 r" ^9 V/ A4 N* f4) Motor Operational Control
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0 y/ t; D4 |$ _8 K' w! Z* u) x! f# NSpeed Control
1 w! n# h+ F r3 l, [Reversing 1 Y1 L: o7 _, b2 v6 ^
Jogging & b' T2 K* ?) `
Sequence Control |
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