Hanna Instruments HI 8000 Series - Manual (Page 65)

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sensor #1) is outside of the allowable dead band determined by the specified pH
Reference value together with the pH min and pH max offset limits. These param-
eters can be set using panel S 40 (pH CONTROL).
4. “EC OUT OF RANGE”
This alarm is triggered when the real time value of the primary EC sensor (EC
sensor #1) is outside of the allowable dead band determined by the specified
EC Reference value together with the EC min and EC max offset limits. These
parameters can be set using panel S 41 (EC CONTROL).
5. “DIRTY FILTER: n”
This alarm indicates that the “n” designated filter requires cleaning. The
customizable alarm behavior of the Fertigation Controller allows automatic
execution of the corresponding filter cleaning program or only the alarm with
continuation of normal function with no execution of a filter-cleaning pro-
gram. These parameters can be set using panel S 46 (FILTERS CTRL), “Clean
on alarm” option.
NOTE: This option, when set for filter #1 or filter #2, applies to BOTH filter-
cleaning programs.
6. “LOW LEVEL FERT: n”
This alarm is triggered if the fertilizer level of the “n” designated tank has reached
a minimum value. Once this alarm is triggered, the assigned valve will close
and that fertilizer tank will be excluded from use during EC control of the
irrigation process.
7. “LOW LEVEL ACID”
This alarm is triggered if the level of the acid (or alkaline) tank has reached a
minimum value. Once this alarm is triggered, the assigned valve will close
and that tank will be excluded from use during the pH control of the irrigation
process.
8. “NO WATER SUPPLY”
This alarm is triggered due to an incoming water supply failure event.
The Fertigation Controller is automatically switched to BLOCK state and all
irrigation programs are SUSPENDED until this event clears. Once the event is
cleared the Fertigation Controller automatically resumes normal operation
in the previous state without any external intervention.