KROHNE OPTISENS AAC 050 EN - Manual (Page 23)

Manual OPTISENS AAC 050
23 OPTISENS AAC 050
5.8 Limit values
Main menu
.
. Limit values
Limit values Limit S1 Relais 3 is switched ON if the measured value
1.00 mg/l Exceeds limit S1
Limit S2 Relais 3 is switched ON if the measured value
0.30 mgl Drops below limit S2
Turn-on delay The alarm I issued only if the cause of alarm
005 sec. Remains longer than the delay time
For the alarm, you can adjust two limits:
• Limit 1 is an upper limit. If the measured value exceeds limit 1, an alarm is issued.
• Limit 2 is a lower limit. The alarm is issued if the measured value drops below limit 2.
In case of alarm the display shows the message „limit 1“ (or 2, respectively) and relay 3 is switched ON. This
relay can be used to activate an external horn or lamp.
NOTE The limit function is active only if the controller is set on automatic mode. When you switch the controller to
MAN, the alarm is extinguished.
5.8.1 Turn-on delay
In some applications it happens regularly that the measured value exceeds a limit for a short period of time.
To avoid having an alarm issued under these circumstances you can adjust a turn-on delay which has to
pass before an alarm is issued. If the turn- on delay time is >0 then the alarm is issued only if the cause of
alarm remains longer than the specified turn-on delay time.
5.9
Dosage check
Main menu
.
. Basic settings
Basic settings
. Controller settings
. .
Contr. settings .
Dosage check
S1 10 min
In the basic settings of the controller you can define, how long a controller is supposed to dose with 100%
without raising alarm.
If the controller output is 100% for more than the specified time, this is interpreted as an indication of failure,
and the device issues an alarm and deactivates the controller, thus stopping further dosage.
The dosage check is a safety catch to prevent hazardous chemicals to be set free in case of a defective
dosing tube or tube connection.
NOTE In case of an alarm due to dosage check, only the controller concerned is deactivated.
NOTE If you set the dosage check time to 0 seconds, the dosage check function is deactivated.