 鲜花( 30)  鸡蛋( 0)
|
ELECTRIC MOTOR CONTROLS
& |; |: k8 O& |$ B6 n' [& ?3 b3 \( n- p; O: c
Once the proper motor is selected, understanding the many various control devices available and + d. Z8 h3 V! j1 w" t9 b& ~
their uses and limitations becomes an important part related to reliable operation and protection of
; R0 r. g7 R' f* mthe motor and the personnel using the motor.
( {" \( f4 U+ y/ Z' F
& C* ]! {" j8 u! j- JMotor Control Topics
/ ^! D5 X8 r3 k+ c5 T6 ]5 r
& A2 C8 m/ C' X( ?" T* yThere are four major motor control topics or categories to consider. Each of these has several : D! ?- y K& B' c) q( R$ Z
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor - F g$ a# s! H5 P, E
control equipment can accomplish multiple functions from each of the topics or categories.
* i, |7 S5 k, G, O3 j ~3 ?; Y# _) K/ k
The four categories include: / k9 \" R* b( X2 h! B' V$ I ?0 ~
) ], W0 i% T$ W) ?0 @
1) Starting the Motor # r m4 \9 w" r+ ^" T, Q9 O
* Z& K8 {" V `9 o8 TDisconnecting Means - w* |8 P& S3 E
Across the Line Starting , O" l$ \1 `6 ~3 [; }; Y& T& T- I
Reduced Voltage Starting
! N4 [) v9 Q! f# w# U9 @
! |( \5 H" @$ z1 h) k/ r1 a
2 f9 ], S* k+ C1 o% }" o* j/ l* [2) Motor Protection 2 ?1 H+ d2 ]0 M1 I' Z2 s
' ~0 I. g9 H. V4 N; E" t
Overcurrent Protection ! L% m" r, V7 m5 H+ u9 B
Overload Protection
4 d$ p+ X/ N' ^- p9 fOther Protection (voltage, phase, etc) $ v3 p- D- w) {+ o/ _
Environment : m' ]$ M% B. \% M
1 J# [9 `8 r3 \6 {
5 e# `3 [* x i4 `7 E% k. C
3) Stopping the Motor / [* T0 X' u" ~8 ^7 M
8 T. L& a- ^' ?
Coasting ! ]# S9 c: Y4 G" R+ [- X {4 X: c
Electrical Braking
8 u. e; y; Y* w7 b: U! NMechanical Braking
6 V; N! ^3 l A% N+ Y% m6 G- b8 }
- U5 W: A$ v+ e r
* c9 d# Q# X! G R3 N4) Motor Operational Control
3 G4 i2 W; E9 f% y- [& J, T- B j0 I
Speed Control , Z' V4 @8 o0 `3 w4 l; A' \: E+ n
Reversing , C( I+ P1 N3 e
Jogging
: ^7 ]0 h6 Y4 r+ ]9 ]& PSequence Control |
|