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ELECTRIC MOTOR CONTROLS
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/ b/ ~0 e9 [' b r5 @% ?+ QOnce the proper motor is selected, understanding the many various control devices available and 3 v+ J Y" ]) u( M9 \2 ~$ g
their uses and limitations becomes an important part related to reliable operation and protection of ) P' e! v6 t/ T
the motor and the personnel using the motor. ) _% t2 C8 _8 O+ L* R5 {0 r9 x
$ \0 V. P _/ C- J8 TMotor Control Topics 7 e- s' A: Y. \) M
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There are four major motor control topics or categories to consider. Each of these has several ( j9 T7 q: b' ^$ s% z9 V, Y& j
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor
! i6 c' ] n& c3 v2 v5 `" X$ Jcontrol equipment can accomplish multiple functions from each of the topics or categories. " T" X' n7 C/ y- }9 O
7 Q R( O, u+ Z) f- d3 IThe four categories include: : s# o+ B' k! ?& m: h' P
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1) Starting the Motor
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Disconnecting Means - M! I1 e' E) x1 @) M
Across the Line Starting
) D4 g# ^9 U2 F! A9 e8 h) BReduced Voltage Starting
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2) Motor Protection 0 E3 o. M9 b! C5 A1 r" E
7 z3 M: Y7 v8 H- q4 FOvercurrent Protection 7 ^! @, Q8 K) g- R4 A
Overload Protection , k- A5 R9 h( {1 Q8 U
Other Protection (voltage, phase, etc)
& P! T+ i/ V: q1 @- vEnvironment
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) o! ~( R, C* J# {& y- c3) Stopping the Motor
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& F8 [& @( X" H7 G6 SCoasting
/ a2 Z: m* C, D* p/ y3 f/ C" ~Electrical Braking
1 M7 U! ^* V* |Mechanical Braking * j8 d9 g7 {9 l7 q, M) `
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2 r# Y% D9 X& N. v4) Motor Operational Control
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Speed Control 6 D# C. K Z( v
Reversing i7 I9 H7 M! o
Jogging ( ]6 Q9 w/ `8 p* \7 n& e/ j
Sequence Control |
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