Hach-Lange RTC103 N-Module - Manual (Page 47)

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Parameterization and operation
7. Press ENTER ( Figure 4 , item 1) to confirm the list once it is
finished.
Note: The order of selected sensors has to be defined and
pre-configured by Service of Supplier on CF-card of RTC103 N-Module.
4.7 Control programs
To adapt to local circumstances and the instruments available,
there are 4 different programs available for calculating desired
DO concentration for nitrification
The choice of program depends on the available measurement
signals.
Suitable program has to be selected and pre-configurated on CF
card from RTC103 N-Module by the Service of supplier!
4.8 Automatic program change
If a measurement signal fails, e. g. during an operational fault, an
automatic program change occurs using only the available
measuring signals and replaces the failing measurement by this
fallback strategy. If the measurements are available again after a
failure, it is automatically switched back to the preselected
program. The change between programs occurs with a delay of 5
minutes.
4.9 Explanations of nitrification controller parameters
4.9.1 SRT MODE
Three different types of operation regarding the Sludge Retention
Time (SRT) can be selected
• MANUALLY: The SRT is provided as a manual input to the
controller, if no TSS measurement is available in aeration
tank.
• SRT-RTC: The SRT is provided by a separate SRT-RTC and
forwarded to the RTC103 N-Module.
• TSSml: The SRT is calculated based on MLSS concentration
and the amount of daily removed TSS mass.
Table 2 Control programs to calculate the desired DO concentration for nitrification
NH4-N influent nitrification Calculate desired DO concentration based on NH
4
-N load to nitrification, only.
NH4-N influent and TSS
Calculate desired DO concentration based on NH
4
-N load considering the current
Sludge retention time
NH4-N influent and NH4-N effluent
Caluclate desired DO concentration based on NH
4
-N load to nitrification and NH
4
-N
effluent concentration.
NH4-N influent, NH4-N effluent and
TSS Caluclate desired DO concentration based on NH
4
-N load to nitrification and NH
4
-N
effluent concentration considering the current Sludge retention time.