Xylem IM043 AQUAVAR Variable Speed Pump Control - Manual (Page 42)

Offsets
41
It is also possible to use second sensor input as an offset for the primary required value. An example
would be locating the second sensor in a supply tank or well and setting an offset so that when the
water level got too low, the pump discharge pressure setting would be reduced until the tank or
well had recovered.
Another example would be the use of both a pressure sensor and flow sensor in the discharge line
so that if the flow became too high for the pump, the offset could reduce the discharge pressure set
point to keep the pump from cavitation.
To Implement the offset function,
Enter the submenu by holding the key.
Enter the password and press the key.
Press the key until you see the screen:
Enter the submenu by holding down the key.
Use the and arrows to select the source of the
second value:
EXT ADC-1 for 4-20mA input
EXT ADC-U 0-10V 0-10V input
EXT ADC-U 2-10V 2-10V input
Refer to the following page to determine the offset variables and intensities to use for your applica-
tion.
Example for Offset:
Sensor range: 20mA
=
150 PSI Required value: 75 PSI
Level 1: 20% of the 2nd additional input Level 2: 80% of the 2nd additional input
Intensity 1: -10%
=
-15 PSI (refer to the required value)
Intensity 2: -20%
=
-30 PSI (refer to the required value)
Programming
iTT CORPORATiON
20 PSi
PASSWORD
0066
SUbMENU
OffSET
OffSET iNPUT
Off
OffSET iNPUT
ExT ADC-1
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