Xylem IM043 AQUAVAR Variable Speed Pump Control - Manual (Page 6)

5
Typical Constant Pressure Systems
The following diagrams show typical single pump and multi-pump systems using the AQUAVAR con-
troller. Connection can be made directly to a water supply or water can be drawn from a supply tank
or well. In the case of supply tanks and wells, level switches, (item 10) can be used to shut down the
pumps when water is low. In the direct connection, a pressure switch on the suction side (item 8) can
be used.
A diaphragm pressure tank is used on the discharge side of the pump or pumps to maintain pres-
sure in the line when there is no demand. This will keep the pumps from continuing to run. With the
AQUAVAR controller control unit, it is not necessary to have a large tank for supply purposes. In select-
ing a tank, make sure it can withstand maximum system pressure. The tank should have a capacity of
about 10% of the maximum system flow rate in gpm. Pre-charge the tank to the following:
System Design
1 Pump with AQUAVAR controller
2 Diaphragm tank
3 Distribution panel
4 Gate valves
5 Check valves
6 Foot valves
7 Incoming pressure switch
8 Pressure gauges
9 Level switches
10 Supply tank
11 Pressure transmitter
Closed loop circulator systems may not require a pressure tank.
Note
Systems MUST be designed by qualified technicians only.
Note
PSI Set Pressure 15 30 45 60 75 90 105 120 135 150
PSI Tank Pre-charge 12 21 37 52 64 77 95 117 125 138
Diagram 2
Single Pump Layout
Diagram 1
Multiple Pump Layout
Indirect connection
via tank
Suction out or a well Direct connection
9
10
9
6
8
7
4
3
7
4
7
4
1
1
1
11
5 4
11
5
4
11
5 4
2
8
8
4
7
1
5
4
8
11
2