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ELECTRIC MOTOR CONTROLS - L+ S, ]% N2 d- G+ \
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Once the proper motor is selected, understanding the many various control devices available and
W' |1 w( O# |+ F1 jtheir uses and limitations becomes an important part related to reliable operation and protection of - }5 O5 G8 s8 B( D3 N/ J( Y" n7 E8 j
the motor and the personnel using the motor. * R0 K0 `. [* s* I) T- Q8 N
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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 4 H$ g' K) P9 M0 Q
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
: j& l/ s( w# G$ A9 `" F+ rcontrol equipment can accomplish multiple functions from each of the topics or categories.
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The four categories include:
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: e9 S" E/ j# ~1 Y3 d% x/ ?' t- R: o1) Starting the Motor , z# @6 ]( R7 m$ v
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Disconnecting Means 7 @& V5 `* ?- G' a$ L4 e: I9 R# t& G
Across the Line Starting
7 X' o' K/ E/ KReduced Voltage Starting 8 I( T2 Y& r# Z7 R5 R' i
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2) Motor Protection : V5 K2 F, h1 T$ d! K8 S
T, M) C, T. O6 A9 C0 ~" l% IOvercurrent Protection * x* M5 i& t' b1 E) G6 { A' i9 _$ S+ W
Overload Protection
7 R! k, W2 K! e8 q: oOther Protection (voltage, phase, etc)
1 J) d G0 L: H6 g& p$ \: Q$ yEnvironment " R: b) A2 g0 ~; ]; [1 g: l
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( B6 Z6 F& o3 u: |3) Stopping the Motor
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3 O7 C$ ~. D" p: z% i0 K1 {9 h& LCoasting . l8 P# |% O7 W" j
Electrical Braking
$ u) A, ]& t! \% ^9 V! E, T' BMechanical Braking ( `1 m+ t1 A+ G, k
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- ], k" E2 o5 ~2 G4) Motor Operational Control
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- j! t; c& N2 ~& ~. t3 m; c& Z" l0 wSpeed Control
+ E/ ]( N" G# W5 o) j% m/ U, \5 i FReversing
7 D3 K/ E }. M+ }' b' ]Jogging
% a- w3 o% g2 U$ E1 t TSequence Control |
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