Xylem IM098 AQUAVAR Model 56 Controller - Manual (Page 25)

IV. Circulator Applications
On circulator pumps, the system curve can be automatically tracked through the use of a differential pressure
transducer. This pressure transducer reads the outgoing discharge pressure and the incoming return pressure
and compensates for differences in pressure as demand and speed increase. Programming is the same as just
covered for the single transducer version. Data on the differential pressure transducer can be found in
Appendix A.
V. Multiple Pump Constant Pressure System Curve Compensation
(Flowchart #4)
When two, three or four AQUAVAR Model 56 Controller controlled pumps are connected in a system, they
can be programmed to work together to maintain system pressure up to the maximum flow rate of all the
pumps combined. As the first pump reaches its maximum speed and flow, the second pump will
automatically turn on (and so on). In addition, the sequence of the pump that will run first (lead pump) can be
automatically varied to reduce premature wear on any one pump in the system.
1) Refer to the section “The Main Menu - Setting One Pump Constant Pressure”. Follow the step
then continue below.
Instructions
2) From the Parameter screen on the main menu
press the arrow until the display changes to:
3) Press the arrow until you reach the number
0066
4) Press the ➔ arrow repeatedly until you reach:
5) Press the arrow and the display changes to:
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.
Programming
20
PASSWORD
0000
PASSWORD
0066
SUBMENU
MULTICONTROLLER
ACTUAL VALUE INCREASE
0.0 PSI
➔
➔
➔