Pre-Bleeding; Pre-Circulation - Ecolab MULTRONIC Manuel Technique

3.3

Pre-Bleeding

Pre-bleeding should prevent a bleeding process from starting immediately after a
biocide metering and therefore the biocide chemical is blown off without effect into the
drain.
If the conductivity value at the planned start of a biocide metering process is higher
than the bleeding threshold Ws, the bleeding will preferred. The biocide metering is
only started after the bleeding process has ended and the bleeding valve has closed.
The bleeding threshold Ws is set to the % of interval {[W+] – [W-]}.
The interval between the lower set point W- and the upper set point W+ corresponds to
100% of the measuring range of Ws extending from 10% to 90%. (See also Timer
Module Description Chapter 4.8.1))
Setting example:
upper nominal value W+:
lower nominal value W-:
threshold value Ws:
The bleeding threshold is calculated as follows:
Ws = {([W+] – [W-])/100}
Ws = {(1600 –1400)/100}
In this example, above a value of 1580 µS/cm, an advanced bleeding is started if a
biocide metering is present.
3.4

Pre-circulation

Communication between Multronic and the circulation pump is integrated in order to
prevent biocide metering from taking place without circulation running.
If the timer has a pending biocide metering, first a check will be done to determine
whether there is a circulation pump running message present (contact between
terminal 89/90 closed / release).
If there is no release present, the 2nd relay assigned to the bleeding module is
activated (e.g. relay no. 3, terminal 5/6 normally open contact or terminal 5/6a normally
closed contact in slot 1). Afterwards, it will be checked again if there is a running
message of the circulation pump present on the terminals 89/90.
If the release is now present, it will wait for the set pre-circulation time (see Operating
Manual Timer Module, Chapter 4.1 Controller Parameters / Timer, sub section "Pre-
circulation").
At the end of the pre-circulation time the biocide metering process is started and,
depending on the preselection (see Operating manual Timer module, chapter 4.1
Controller parameter / Timer, sub section "Metering relay") one or both of the relays
assigned to the timer module (relay 4 + 5 for slot 2, relay 6 + 7 for slot 3) is activated
for a previously set metering time (see Operating manual Timer module, chapter 4.1
Controller parameter / Timer, sub section „Metering Time"). Relay 3 is not reset until
the subsequent tracking time (see Operating manual Timer module, chapter 4.1
Controller parameter / Timer, sub section "Tracking time") has ended.
If there is no response after activation of the circulation pump at release input, after the
time period has elapsed (see Operating Manual Timer Module, Chapter 4.1 Controller
Parameters / Timer, sub section "Max. Interruption") the alarm "Biocide interruption
exceeded" will be shown in the display.
The bleeding regulator stays blocked during pre-circulation and biocide metering
process.
If the release contact (terminal 89/90) is bridged, the pre-circulation is stopped.
417101341_Anhang14_Kuehlwasser.doc
Cooling water treatment
1600 µS/cm
1400 µS/cm
90 %
Ws + [W-]
*
90 + 1400 = 1580 µS/cm
*
- 23 - Rev.: 05-07/10