Xylem HYDROVAR HV 4.150 / 4.185 / 4.220 User Manual
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0500
0500 SUBMENU
SEQUENCE CNTR.
Using the parameters of this submenu, all necessary settings can be done for running a
multi-pump system (even in cascade relay and cascade serial / synchron mode).
Application Example:
1) Lead pump reaches its ENABLE FREQUENCY [0515]
2) Actual value falls and reaches the cut in-value of the 1
st
assist pump
Cut in-value = REQUIRED VALUE [02] – ACT. VAL. DEC. [0510]
Î
the 1
st
assist pump is switched on automatically
3) After the start up the new required value is calculated in the following way:
NEW REQUIRED VALUE = REQ.VAL. [02] – ACT.VAL.DEC [0510] + ACT.VAL.INC. [0505].
The new required value is shown in the main menu as parameter EFF.REQ.VAL. [03].
Calculations of the new required value for multi pump applications:
k ... number of active pumps (k >1)
p = p
set
+ (k-1)*[lift value – fall value]
• Lift value = Fall value ⇒ Pressure constant independent how many pumps are in
operation
• Lift value > Fall value ⇒ Pressure rises when assist pump switches on
• Lift value < Fall value ⇒ Pressure falls when assist pump switches on
S