Xylem IM131R01 AQUAVAR AV II - Manual (Page 66)

Submenu Sequence Control - for further information see Section IX, page 53
Use this menu to allow starting and stopping of up to 4 pumps with the RS-485 communication
port. The following setup items allow the user to determine when the pumps will start and stop.
Actual Value Increase
Enter a value to increase the setpoint (required value) after a lag pump starts.
Actual Value Decrease
Enter a value to decrease the setpoint (required value) after a lag pump starts. The required value
will be calculated from the following equation after a lag pump starts:
NEW REQUIRED VALUE = REQUIRED VALUE - ACT. VALUE DEC. + ACT. VALUE INC.
For no modification to the setpoint keep both of the increase and decrease values at the same
value.
Enable Sequence Control
Enter the maximum speed prior to starting the lag pump(s). Typically set a +2 HZ below the
maximum frequency. To disable pump staging set this value greater than the maximum frequency.
Switch Interval
Enter the amount of time the lead pump should operate prior to alternating the pump sequence.
This variable allows equal wear on all controlled pumps. Set this value greater than 100 hours to
deactivate alternation.
Source Required Value
Used to set the address for the source of a second required value. May be set to off, ADR1, ADR2,
ADR3 or ADR4.
Submenu Synchronous Control
To use this method of multiple pump control, all pumps must be exactly the same. When the syn-
chronous control is active all of the activated pumps work together to satisfy the required value.
When the synchronous control is deactivated the lead pump(s) run at full speed while the lag
pump modulates in speed to satisfy the required value.
Synchronous Limit
To deactivate synchronous control, set this value below 0 HZ. This will be the lowest speed that
multiple pumps will operate prior to switching off the last pump in sequence. For 60 Hz systems
using synchronous mode, this would normally be set to 40 Hz. This window is also used for the
stop value of a slave pump.
Synchronous Window
This is a frequency offset that increases the synchronous limit that each lag pump is stopped at.
This allows the minimum speed to be increased for each lag pump. For example, if the synchro-
nous limit were set for 40 Hz and the synchronous window is set for 50 Hz. Pump 3 shuts off at
45 Hz and pump 2 shuts off at 40 Hz.
Operator Custom Features and Displays
65