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ELECTRIC MOTOR CONTROLS 4 R( f) o+ H/ F9 }) J7 ?& Z
) N* n* S; Y1 w5 f8 f8 qOnce the proper motor is selected, understanding the many various control devices available and
# [$ ?+ x) ~$ b' ^their uses and limitations becomes an important part related to reliable operation and protection of
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Motor Control Topics $ P0 M, l/ g7 e3 }8 d8 r
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There are four major motor control topics or categories to consider. Each of these has several $ C { Q9 |: W! H6 r
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor ) @, _7 e/ c0 n( x* q! f& p
control equipment can accomplish multiple functions from each of the topics or categories. $ g3 C# s1 p& S2 [5 @5 [ D
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The four categories include:
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7 ~5 |% ~, D6 _; V5 P1) Starting the Motor $ T& y9 r, k. K) Y& D) P7 \" t
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Disconnecting Means ; x2 L2 U9 i% E% K9 a C8 T
Across the Line Starting $ P& p$ \" z" J% W( n
Reduced Voltage Starting
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6 j" @$ ]& J5 X2) Motor Protection ! r* {% ^3 }. T& ~6 C( h+ Q
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Overcurrent Protection
% g9 [$ j6 ^& FOverload Protection ) \4 f/ ?; B% Z" p+ _" M; S
Other Protection (voltage, phase, etc) i4 T% U. C, U8 V: ?6 c
Environment & L( p" C+ ]( e* m
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3) Stopping the Motor
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Coasting 1 u+ F" z; D z1 \+ L3 j( ^/ m. ]9 X G5 H
Electrical Braking 9 ^. n( a+ r( A1 Y9 o% l' P
Mechanical Braking
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/ Z1 F: U0 B$ G2 Q+ d7 G, y' S4) Motor Operational Control ) B& |! g6 u8 v; j& @3 U
4 M. R' H- Z" _" |Speed Control
+ C, E$ Y+ C" s& k- n! WReversing
# N7 J4 h/ s4 g2 X+ \# }8 oJogging
8 r8 a2 N, N- P/ OSequence Control |
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发表于 2009-6-19 21:51
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