 鲜花( 30)  鸡蛋( 0)
|
ELECTRIC MOTOR CONTROLS
* o: v3 D: W6 }9 N$ Q1 B) U" J8 v1 M3 a
Once the proper motor is selected, understanding the many various control devices available and ( F) g* j5 \3 V% l8 x$ }5 M: _9 F
their uses and limitations becomes an important part related to reliable operation and protection of * y/ J9 [: a( J6 V/ @
the motor and the personnel using the motor. # _0 `) X* U& m) N% G' t
" h0 t, @' i' a* A5 w oMotor Control Topics 9 T) n5 }, R( q$ A, i5 f' V
# h; a; T( _$ @1 M6 o* X6 i+ r
There are four major motor control topics or categories to consider. Each of these has several
$ O% V/ f) v. W9 `' wsubcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor - F( E' Q. G- n" o# u j2 B
control equipment can accomplish multiple functions from each of the topics or categories.
% [4 y& @# }$ }1 B1 o# B$ E! Z0 B, y; S
The four categories include:
1 [0 K0 @. d! m+ }
( Z9 ^( O3 F% v: \1) Starting the Motor
8 M9 U& C4 ~9 k0 i3 T/ H% d- V" f. t
Disconnecting Means
1 s% |2 V) h7 f5 k! c( xAcross the Line Starting * u" s: e) ~4 {. }9 n" U1 \
Reduced Voltage Starting 9 A* [/ \1 J! t
" ?- D) l8 `4 o# G9 @& ?& ^4 ]; @ i* B( _6 \4 O9 U1 i9 H
2) Motor Protection
7 F# }- n7 p9 N9 E+ X) Y5 k6 W6 K; c+ j7 o% M. W/ A, w3 u' T
Overcurrent Protection
6 m" S4 R7 ? c6 o; p+ R3 W, hOverload Protection
0 h2 V( }) B& y$ {" y9 G/ \Other Protection (voltage, phase, etc)
" |8 s7 g/ L; E$ _6 K$ H0 z; qEnvironment , U; B# K) r+ j" {2 r' ]
% s/ g0 H; d. {8 C2 g# E
3 t" S3 `) s3 T3) Stopping the Motor
+ U+ p0 Z" `- z8 L2 p2 |$ A6 V. W
Coasting
( `0 M/ T9 u" d" o: [5 @Electrical Braking ; J" o) I& G: S% [! S
Mechanical Braking
" S+ `* Y$ |3 m! \
- h5 B2 }9 V D
, n* A: o G. |3 M4) Motor Operational Control
3 N5 m! p4 K: v1 J& |/ E) C/ J
, ?; S# ]! {4 [" I7 u- {6 GSpeed Control ( n" |. ?8 g6 ]" @
Reversing
/ ~' B; z- @. x+ p: U( @Jogging 5 G( h& K& W8 h4 s2 Y
Sequence Control |
|