Xylem HYDROVAR (HV2.1 - 3.45) - Manual (Page 54)

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9.22 Submenu Sequence control
Using the parameters in that submenu all necessary settings can be done for running a multi-
pump system. Each parameter within this submenu must be changed only on one HYDROVAR
of the system, because it will be transferred via the RS485 interface to each connected
HYDROVAR. Up to four pumps can be connected using the integrated RS-485 interface.
S U B M E N U
Seq. Control
Press ¾ for about 3 seconds to enter the submenu
Press the ¾ button shortly to change to the next
parameter (-> chapter 9.23)
Application Example:
1) Pump 1 reaches fmax (maximum speed)
2) Pressure falls and reaches the start-value of the 2
nd pump
(=REQUIRED VALUE–ACTU. VALUE DEC.)
Î
Pump 2 is switched on automatically
3) The required value is calculated new, after starting the 2 nd pump in the following way:
NEW REQUIRED VALUE = REQUIRED VALUE – ACTU. VALUE DEC. + ACU. VALUE INC.
Calculation of the new required value for multi pumps application (Multicontroller Mode):
k ... Number of active pumps (k >1)
p = p
set
+ (k-1)*[lift value – fall value]
• Lift value = Fall value ⇒ Pressure constant even all pumps are in operation
• Lift value > Fall value ⇒ Pressure rises when lag-pump switches on
• Lift value < Fall value ⇒ Pressure falls when lag-pump switches on
The following 3 parameters are responsible for switching ON/OFF the lag pumps and for the
calculation of the new required value as well.
9.22.1 Lift Value (actual value increase)
ACTU. VALUE INC.
0.35 Bar
Adjustable between 0 to the pre selected Sensor range
Press the ¾ button to change to the next parameter
9.22.2 Fall Value (actual value decrease)
ACTU. VALUE DEC.
0.15 BAR
Adjustable between 0 to the pre selected Sensor range
Press the ¾ button to change to the next parameter