Xylem IM043 AQUAVAR Variable Speed Pump Control - Manual (Page 40)

Programming
39
vIII. variable Second Required value
In this section, we will cover the set up and programming of the AQUAVAR for a second sensor
input. This sensor can be either a 4-20mA or 0/2-10V device such as a pressure transducer, flow
transducer, heat sensor, etc. When connected to the AQUAVAR, the output of this second sensor
becomes the new set point. As input from the second sensor changes, the set point will also change.
Example: If the second sensor was a 150 psi 4-20mA pressure transducer and the input to
the AQUAVAR was 10mA, the set point would become 62 psi. If the input dropped to 8mA,
the set point would go to 94 psi. Keep in mind that this change only offsets the set point.
Motor speed continues to be varied by the primary transducer reading of demand change.
This function could be used for chlorine or fertilizer injection where a flow sensor in the main
pipe would track system demand and adjust the pump flow set point to keep the mix per-
centage the same.
Electrical
Connect the second sensor as shown to X1/10 and either X1/12 for 4-20mA or X1/13 for 0/2-10V.
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Digital Input
X1
Voltage signal input 0..10V or 2..10V
Current signal input 4..20mA
Analogue signal output 0-10V
Ground
Motor thermoswitch or PTC
Low Water
External on/off
+15 VDC max. 100mA
Actual value signal input 4-20mA
Screen
external
current signal
Switch