Appendix V
172
V-11. Air compressor constant pressure control (sensor for
two-wire pressure transmitter)
V-11-1 electrical diagram:
+
-
P
380/400V50/60Hz
Threephaseinputpowersupply
Circuitbreaker
Motor
M
%
FWD/STOP
REV/STOP
Constantpressurecontrolofaircompressor
Twowire pressuresensor
4 ~ 20mAfeedback
Aircompressor
ST500
V-11-2 Connection:
Short circuit between COM and GND;
+ 24V, AI1 indirect pressure sensor feedback 4 ~ 20mA current signal;
DI1, COM indirect "forward / stop" signal, DI2, COM connected to "fault reset" signal;
AI1 jumper cap shorted to I end.
V-11-3 Parameter setting
Frequency source master setting
Terminal block control (LED on)
0.00 ~ maximum frequency
(F0.19)
Upper limit frequency offset
0.00 ~ Upper limit frequency
(F0.21)
DI1 terminal function selection
DI2 terminal function selection
Set the desired
pressure value
percentage based
on the pressure
value actually
required
PID automatic deceleration
frequency option
Computing status after
PID stop