521-OM0108.88
Copyright
2009 Nalco Company
6-34
Technical Help
(630) 305-CHEM
3D TRASAR
5500 - Installation & Operation Manual
32. How do I know that 3D TRASAR Bio-Control is working?
In the controller display [press on keypad: Information —> System Performance] the Nalco Bio-
Index will be shown with a ‘starting value’which can range from zero ‘0’down to as low as -20 or -
30.
A minimum of one hour of data has to be acquired before a calculated value is shown. If the sys-
tem has just been dosed with bio-reporter, it will take between 4-24 hours (depending on microbial
activity) for the Ratio_Value to reach the control Ratio set point. During this period, oxidizing bio-
cide will not be applied to the system. If after 24 hours oxidizing biocide has not been fed into the
system please call 630-305-CHEM.
When you wish to follow the 3D TRASAR Bio-Control algorithm and verify correct operation the
easiest thing to do is to download the 3D TRASAR Bio-Control data file (through data download
screen). The file can be opened in Excel and the Nalco Bio-Index can be reviewed along with the
‘ox pump on time’. The ox pump on time is the length of time (in seconds) the 3D TRASAR Bio-
Control turned the oxidant pump on each 20 minute decision interval.
You can also verify that the oxidizing biocide relay has been feeding biocide by checking the [Calcs]
portion of the ‘General Data’log in column Z [Ox Bio Relay Duty %] . You will see a number (per-
centage) listed if the ox_biocide relay has come on in the previous 24-hour period.
The Nalco Bio-Index value should be between -10 and +10 during normal operation of 3D TRASAR
Bio-Control after the initial 4-24 hour period has elapsed.
33. How do I determine if the Rz concentration in the system has reached 20 ppb?
• Check the 3D TRASAR controller display.
Press
Information
key, select
Diagnostic Data
, select
Fluorometer Data
, select Rz
(ppb).
• Check the 3D TRASAR configurator.
Connect to the controller. Once connection is established, the Controller menu will appear.
Select
View Current Readings
,
Data Tab
. Under
System Performance
box locate the
Bio-reporter value
in ppb.
34. Can I trim-feed oxidizing biocide with a separate pump at low level to
continuously maintain a halogen residual while on 3D TRASAR Bio-Control?
Only if the oxidizing biocide is being applied to the Make-Up water AND the conditions that prevent
3D TRASAR Bio-Control use in systems with high halogen levels in Make Up water do not apply.
If oxidant is fed by external (not 3D TRASAR Bio-Control) control into the tower water, it is likely
that there will be overfeed during times of low microbial activity resulting in degradation of the bio-
reporter and BioProduct signals. To compensate, more dye will be added to the system and the
water will become colored.
