Xylem hydrovar, Installation, Operation And Maintenance Manual

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p = p
set
+ (k–1) * (P505 ACT.VAL.INC - P510 ACT.VAL.DEC)
• P505 ACT.VAL.INC = P510 ACT.VAL.DEC
→
Pressure constant, independent of how
many pumps are in operation.
• P505 ACT.VAL.INC > P510 ACT.VAL.DEC
→
Pressure rises when assist pump switches
on.
• P505 ACT.VAL.INC < P510 ACT.VAL.DEC → Pressure falls when assist pump switches
on.
To find out the right setting for Syncronous control
1. Start the first pump in P62 JOG mode.
2. Increase the frequency until the required value is met. Check the frequency at zero
consumption, f
0
.
3. Set the synchronous limit, f
0
+ 2..3 Hz.
4. Set the synchronous window between 1 or 2 Hz depending on the pump curve and the
set point.
11.5 Example: P900 SUBMENU OFFSET
General settings
Constant pressure system with the required value of 5 bar.
Additionally a flow sensor is connected to the offset input.
Parameter P907 OFFS.RANGE = 160 (maximum range of flow sensor = 16 m
3
/h).
System requirement 1
• Constant pressure: 5 bar
• Flow rate: 5 - 12 m
3
/h
Below 5 m
3
/h decrease the pressure to maximum 2,5 bar at a flow rate of 2 m
3
/h.
Settings:
• Parameter P910 LEVEL 1 = 50 = 5 m
3
/h. First limit where the offset function is active.
• Parameter P912 OFFSET X1 = 20 = 2 m
3
/h. Fixed point according to the requirements.
• Parameter P913 OFFSET Y1 = 2,5 = 2,5 bar. Maximum allowed pressure at this flow
rate.
System requirement 2
• Constant pressure: 5 bar
• Flow rate: 5 - 12 m
3
/h
Above 12 m
3
/h increase the pressure with the limitation to have maximum 6,0 bar at
maximum flow rate of 16 m
3
/h.
Settings:
• Parameter P915 LEVEL 2 = 120 = 120 m
3
/h. Second limit where the offset function is
active.
• Parameter P917 OFFSET X2 = 160 = 16 m
3
/h. Fixed point according to the
requirements.
• Parameter P918 OFFSET Y2 = 6 = 6 bar. Required pressure at this flow rate.
11 Technical Reference
HVL 2.015-4.220 Installation, Operation, and Maintenance Manual 105