 鲜花( 30)  鸡蛋( 0)
|
ELECTRIC MOTOR CONTROLS
0 J0 f- s: d0 d- L2 D+ `9 n; l
; D* j2 J$ Y( C; s4 F$ U6 TOnce the proper motor is selected, understanding the many various control devices available and
/ i& [* |3 G2 S$ p% Wtheir uses and limitations becomes an important part related to reliable operation and protection of
3 E G& y$ N: c1 Zthe motor and the personnel using the motor. 7 i9 B( |, {! S+ L* r
1 o. t1 k( t* @' l# ]! V8 B3 y# B( q
Motor Control Topics ! a6 H7 R; \: Y
* H1 j- J2 E" K) [1 I1 L% F
There are four major motor control topics or categories to consider. Each of these has several / `/ `' T. w' Q
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor ) N+ E# \7 B: i& ^0 l
control equipment can accomplish multiple functions from each of the topics or categories.
- @& a- m4 g( k, H9 x4 q, l$ g, C
% o E0 }, ^( j ~The four categories include:
$ E! N7 i6 a/ _" V
, `& P% s, G8 b. b; `! f1) Starting the Motor
! k; f- C; n( O0 _! d
* [: k# D6 z( N. G# c4 I4 CDisconnecting Means
& I1 S' C( T. A! _1 PAcross the Line Starting " z' {( I l5 X, q# j
Reduced Voltage Starting ! _5 A# _" A, `& `( a- D
6 {7 u$ L) v- l* k% J6 a0 F' E; n% K5 G( i
2) Motor Protection $ O8 g; I9 g# O* R6 w% x
/ Y& q* `6 p1 Z3 |( nOvercurrent Protection
# F/ X7 Q3 B4 r0 V$ tOverload Protection 0 b( v2 f1 g: C1 q+ x5 M: p
Other Protection (voltage, phase, etc)
8 S- n: M g; C, V* j3 m. SEnvironment
: s7 A% H6 }& ^9 I, Y# l$ n0 R8 d& `+ g; e3 k1 Q7 `
: n0 \* h1 r7 c2 f& _
3) Stopping the Motor
5 u( t0 L5 @* Y
0 K' {2 I$ ~* ?" K: NCoasting % X# D1 V" K& `
Electrical Braking
3 D& l1 J: Y! P' f& Z: s( h yMechanical Braking
3 B& o6 `$ Q W1 T# U1 n l7 {3 o3 Q4 I! o, U2 M0 x/ [- d3 ~
+ ^- T) u Y4 A1 f1 u4) Motor Operational Control % x4 }; r4 N- _* i; H- R
3 t5 D. G) ^" a) I. h
Speed Control
( ?! i9 @* x4 P: ]) T: d# W! I/ wReversing
8 U( o) Q8 h" i; \ TJogging
9 f; N& R& S- ?, e1 eSequence Control |
|