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ELECTRIC MOTOR CONTROLS $ M! Z+ k" T4 H9 c4 o9 P& U
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Once the proper motor is selected, understanding the many various control devices available and & x3 r3 A; L7 Z% \3 }( r
their uses and limitations becomes an important part related to reliable operation and protection of
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Motor Control Topics 7 S8 o- m! ]: x- T8 j" y i
% e: s7 P* n. }; dThere are four major motor control topics or categories to consider. Each of these has several 8 F/ \5 o9 [6 Y& i8 I2 p
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor * r4 h3 |1 ~! U1 q! x
control equipment can accomplish multiple functions from each of the topics or categories.
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/ s7 m$ `/ K% g, `; c# k) oThe four categories include: ( g/ G) ~1 B4 ~7 }
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1) Starting the Motor " V; V$ k1 `* `/ R7 @
5 x" i0 b) A; E- F% ^5 ]Disconnecting Means " T8 q, \5 W2 w+ \ T$ v: i6 a" t
Across the Line Starting
4 a4 _9 L7 z* h+ V# ]( D' vReduced Voltage Starting
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2) Motor Protection
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Overcurrent Protection " Q8 q2 w4 u% Y$ E
Overload Protection
7 p* V8 k4 `# P) o3 fOther Protection (voltage, phase, etc) ) k8 k6 v3 Q4 f, J
Environment
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3) Stopping the Motor - s) G( v, n4 i5 u5 e# R
4 }2 W# \! `6 v+ `8 zCoasting
0 A. y% `5 }9 L6 v. rElectrical Braking w+ Y% Z: b* L: E* O. C& C% Q* ]
Mechanical Braking
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' S% b/ G; C1 ]/ O6 ?1 F7 n4) Motor Operational Control
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Speed Control
" P# j! u' V2 ^, kReversing
9 R. b& x! u; b/ j- j% G0 G9 KJogging
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