Plot MAM-880 - Control Principles; Local Automatic Control

△
1211
CT1
C
B
A
c
b
10 9 8
7
6 5
4
3
2
19
20
21
CT2
a
31302928
27
2625
24
23
22
FG
1
A
B
RS-485
C1
、
ub ua
uc
13
14
15
16
17
18
Figure 4.2.1 Terminal arrangement diagram
Terminal blocks of controller：
1 is common terminal COM1；2 is input terminal for emergent stop signal； 3 is remotely controlled for
on/off signal input terminal；4 terminal is used to detect oil filter blocked； 6 is RS485 A; 7 is RS485 B；8 is the
simulated ground (Earth)；17 and 18 are the AC20V power source；22、23 terminals are Pressure Sensor signal
input；24、25、26 terminals are motor mutual inductor CT1 input；27、28、2 terminals are Fan mutual inductor
CT2 input；30、31 terminals are Temperature Sensor signal input；19、20、21 terminals Used to detect the phase
sequence and voltage；13 terminals is common terminal of output relay；14 terminals controls fan；15 terminals
controls load valve；16 terminals controls angle-shaped contactor；17 terminals controls star-shaped contactor；
18 terminals controls main contactor。
NOTE: Eelectromagnetism coil shall be connected with surge absorber during wiring, and
dotted lines are extendable functions.
5、 Control principles
1、Local Automatic control
①. press down start button for starting: (Y-△start)
There is fives of self-test after controller is energized and it can not be started by pressing start
button .The air compressor starts by pressing start button after self-test finished. The course of
compressor’s start as followed: KM3 and KM2 are energized → Y-type status of start → delay time is
reached (Y-△change-over time); KM3 is de-energized (KM1 and KM3 are interlocked) and KM1 is
energized → motor operates with △ type to finish start. During the course of starting, all
electromagnetism valves are de-energized to achieve no load start.
②. Automatic operation control:
When the motor is started to running in △ status and load the magnetic valve with