20
W27, E27 Foam detection
Function:
monitoring of foam formation in the steam cylinder.
Procedure:
to detect the formation of foam the current value when the water
gets in contact with maximum level sensor (filling end) and the current value
when the water looses the contact with the maximum level sensor are set
in relation to each other.
This relation is called CurrentDrop:
CurrentDrop = I
Sensor-Off
/ I
Sensor-On
If the CurrentDrop value is less than 0.8, a counter is increased by 1. If the
counter has counted up from 0 to 1, a waiting period of 30 minutes starts.
During the waiting time the CurrentDrop is not analysed. If the counter counts
up to 2, the warning W27 is triggered. If the counter has reached the value
of 6 the cylinder is drained and the counter is reset to 0. If within 24 hours
4 drainings occurred the error E27 is triggered.
– CurrentDrop < 0.8:
––> C 1
– CurrentDrop ≥ 0.8 or filling end with 110% current:
––> Counter - 1 (not < 0)
– Counter ≥ 2:
––> W27A(B)
– Counter = 6
––> cylinder draining
– 4 drainings within 24h
––> E27A(B)
Reset of Warning W27
If after a draining the CurrentDrop is ≥ 0.8, the warning is reset automatically.
The warning message is reset too, if the counter has counted back to 0.
Behaviour on activation:
Warning
Error
Display
W27A(B): Foam
E27A(B): Foam
LED display:
-
Red lights
Fault-Remote:
-
Error Relay
Error-History:
W27A(B)
E27A(B)
System:
Unit is draining
Unit blocked and cylinder draining
Time delay:
30 minutes
24 hours
Reset:
automatic reset
Unit Off/On
