Xylem IM043 AQUAVAR Variable Speed Pump Control - Manual (Page 48)

multiple Pump Constant Pressure... continued
Generally, a slight pressure drop is allowed on
the first pump before the next is started. This
allows for brief system fluctuations without
pump cycling. Once the next pump starts,
however, you will want the system to resume
its normal set pressure.
5. To do this, enter the amount of pressure
drop you will allow before the next
pump starts.
Diagram 19 shows the pressure drop
and increase.
6. To increase the pressure even more to compensate for system losses at higher flow, enter the total
of the system drop allowed before next pump starts and the increased pressure desired.
For example, if the pressure drop allowed is 5 PSI before the next pumps starts, and the increased
pressure needed to compensate for system losses is 3 PSI, you would enter 5 + 3, or 8 PSI to
compensate for both system pressure drop and compensation requirements.
Examples: Value Increase = Value Decrease —> Pressure is constant
Value Increase > Value Decrease —> Pressure increases with each additional pump
Value Increase < Value Decrease —> Pressure decreases with each additional pump
7. Pressure Incr. 000 psi This setting tells the AQUAVAR controller how much to increase
the pressure setting when the second pump turns on.
• Hold down the for 2-3 seconds
until the display changes to:
47
Programming
H
Q
7
6
5
4
3
2
1
0
P1 P1 + P2
P1 + P2 + P3
∆
P
∆
P
Diagram 16
This value is cumulative. An extra 3 PSI will be added to the total system
pressure with each additional pump which turns on. For example, if the initial
system pressure was 50 PSI, pump two would create 53 PSI, pump three would
create 56 PSI, and pump four would create 59 PSI system pressure.
Note
ACTUAL VALUe INC. 000 PSI
*