Liquisys M CCM223/253
Commissioning
Hauser
39
Flow monitoring in sample stream
If a flow rate drops below 30 l/h or there is a total flow failure in the sample stream through
the CCA250 assembly, an alarm is triggered if the INS proximity switch is installed. The
alarm becomes active on expiry of the switch-off delay time (field A4).
The alarm signal stops as soon as the required flow rate is restored.While the alarm period
lasts, the instrument automatically stops chemical dosing and the Chemoclean cleaning
function. All relays assigned to PID controllers or cleaning functions revert to normal
position; for the three-point step controller the "closing" contact closes. Dosing and cleaning
resume once the switch-on delay time expires (field A5).The LCD reading flashes for the
period of controller switch-off so that you can immediately recognize the situation.
a0002018
Fig. 30:
Alarm signalling and dosing switch-off by the sample stream
0
1
1
1
1
0
0
0
A
B
C
D
E
F
G
A4
A4
A5
A5
A
Flow in sample stream
G
Flow restored
B
Relay contacts of PID controller
0
off
C
"Closing" contact on three-point step controller
1
on
D
Alarm relay
A4
Field A4 (delay for controller switch-off)
E
Flow < 30 l/h or flow failure
A5
Field A5 (delay for controller switch-on)
F
Flow alarm
Summary of Contents for Liquisys M CCM223
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