 鲜花( 30)  鸡蛋( 0)
|
ELECTRIC MOTOR CONTROLS 7 H$ z( N7 `. Z, ?9 C8 n6 z( D
+ V. i8 `0 @0 Z3 f& R: A m7 v
Once the proper motor is selected, understanding the many various control devices available and
( N2 ~0 v3 a' _9 ~( itheir uses and limitations becomes an important part related to reliable operation and protection of & |' s" k! g; k0 B( T |) f3 x; }
the motor and the personnel using the motor. # |: F& H7 x0 H$ L/ E% k
! Q+ T: J% x4 O |% q
Motor Control Topics $ j, ^# [+ v; f3 y
- x" B- j1 J% c/ iThere are four major motor control topics or categories to consider. Each of these has several 2 T' G3 p" ^: V2 i
subcategories and sometimes the subcategories overlap to some extent. Certain pieces of motor 1 e, m2 L; G+ ^2 p# |1 g, Y
control equipment can accomplish multiple functions from each of the topics or categories.
# c7 T" X. s0 R0 U8 D
* Q3 Y1 i/ Y) b/ S" ~The four categories include: . m" ] L" N$ o v
3 k5 W4 M' O$ k1 C2 ^1) Starting the Motor ! _( }" O v& M" J+ Q! l
( O' j5 {& {- S
Disconnecting Means
$ y5 e/ Y" z3 p- @% S+ O* sAcross the Line Starting 7 |$ I5 H! ^" F2 K
Reduced Voltage Starting
$ c7 X' y5 s1 a
' b' C9 P4 ^8 j- U3 {3 z
, u$ F2 v: k+ R1 h; d2 D8 Z; l; f2) Motor Protection - i( m1 |3 g* Y" `) e& o: s
* S( _$ }! s' j3 \# G3 i
Overcurrent Protection # ^) o) a; D5 [" X4 o1 F1 c8 i* V
Overload Protection
9 w0 O/ ~8 e( F: U; bOther Protection (voltage, phase, etc)
- p# {) v! X* x, j: r+ g% B5 K- BEnvironment 5 f6 Y, f- q( J% H( F
% s. q- p8 M9 a9 U4 c- l
X- H3 D8 O {% t
3) Stopping the Motor . N w5 w2 o6 Z; ~
6 L9 ~& f7 V3 @' U) P
Coasting
7 W# t; i; ]6 o4 t6 o( ]( N" hElectrical Braking " g( S) Z4 y1 ]$ O# v. ^
Mechanical Braking % k. K4 j6 Y1 k' c+ d5 [
2 a0 {0 g/ h: e7 s* Y
7 v( ^; ~$ u7 V- p9 x4) Motor Operational Control
L) H, H/ ~+ e/ V+ S) |' U; a
& z N5 i5 T) J$ s" Q$ \Speed Control
3 T! `/ R! m$ S& f& hReversing & E5 H5 k8 K H4 ~
Jogging / I/ _3 ?; t! N2 f& {
Sequence Control |
|