ProMinent ProMix C, Operating Instructions Manual

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Pr o Minent ProMix
‘S & C’ Polymer Feeder
ProMix Series S&C User Manual
2.8 Calibrate 4-20mA Input
Press ENTER @ 4-20 mA Input
to calibrate the 4-20mA current loop input
from the site’s control system
4-20 mA Input may be calibrated at any time
in Auto or Manual mode.
The present 4-20 mA Input is 38.7%.
Press ENTER to calibrate.
Key RIGHT to move the cursor &
UP or DOWN to change the digit.
Key EXIT to abandon or ENTER to execute.
Displays new, adjusted Remote Setpoint .
Press EXIT to return to main menu.
If the Local-Remote switch is in the Remote position,
any adjustment takes effect immediately and modifies
the 4-20mA output to the polymer pump.
Sidebar:
‘Calibrate Iin’
matches the % display on the polymer feeder with the
remote operator’s %
display.
The underlying 4-20mA level is of less importance than having both of the % displays
(the feeder’s & the remote operator’s) match because the Polymer feed pump operates from
OFF at 0% to maximum ON at 100%.
It’s simpler to calibrate on a % instead of calibrating on a current and making
a non-intuitive 4-20mA loop to 0-100% conversion.
So you don’t need to know that a 32.4% feed corresponds to a current loop @ 9.18 mA.
The factory default scales the 4-20 mA input for 4mA = 0% Pump to 20 mA = 100% Pump.
See Section 2.2 if your site’s 4-20 mA input is not scaled 4-20 mA = 0 to 100%