Xylem HYDROVAR (HV2.1 - 3.45) - Manual (Page 56)

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9.22.6 Submenu Synchronous Control
By using the synchronous control all pumps in the system maintain the set pressure by
running on the same frequency. The 2
nd pump starts, when the 1 st pump reaches the
release frequency (ENABLE SEQ. CONTR.) and both pumps will run synchronously. The
follow-up pump will be stopped, when the frequency drops below the set SYNCHRON.
LIMIT. This function creates a hysteresis effect which prevents the follow-up against a
frequent on/off operation.
S U B M E N U
Synch. Control
Press ¾ for about 3 seconds to enter the submenu
Press the ¾ button shortly to change to the next
parameter (-> chapter 9.22.7)
9.22.6.1 Synchronous Limit
Tip to find out the right Setting:
1. Start the first pump in JOG Mode (1st Window in the submenu), increase the
frequency till you reach the required value. Check the frequency ( = f
0
) at zero
consumption
2. Set the synchronous limit (f
0
+ 2..3 Hz)
3. Set the synchronous window between 1 or 2 Hz
(depending on the pump curve and set point).
SYNCHRON. LIMIT
0,0 Hz
Frequency limit adjustable between 0 Hz and the set
maximum frequency.
Switch off limit of the first follow-up pump. So if the frequency of both pumps is lower than
this selected value, the first follow-up pump will be switched off.
This parameter is also used for the stop value using an external fixed speed pump with
activated Simple Multicontroller in the parameter CONFIGURATION RELAY.
Press the ¾ button to change to the next parameter
9.22.6.2 Synchronous Window
SYNCHRON-WINDOW
2.0 Hz
Adjustable between 0...10 Hz
Frequency limit for switching off the next follow-up
pump.
Switching of the 3
rd pump:
All 3 pumps are running with an output frequency<SYNCHRON. LIMIT+SYNCHRON-WINDOW
Switching of the 4
th pump:
All 4 pumps are running with an output frequency< SYNCHRON. LIMIT+2xSYNCHRON-WINDOW
To leave the submenu press ¾ longer than 3 seconds to change to