Xylem IM167 R8 Aquavar CPC (Centrifugal Pump Control) - Manual (Page 111)

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Parameter Name Value/Range Note(s)
21.02 PRESS INCR 0- 60 HZ This is the frequency at which system curve
SPEED 20 HZ (Default) compensation begins. At speeds below this, no
compensation for increased resistance is made.
21.03 PRESS INCR 0-100% This is the amount that Aquavar will have
0.0 % 0% (Default) increased the set point at maximum speed.
Test Run
The TEST RUN capability allows the Aquavar system to run periodically if it has been inactive.
The most common circumstance for which Test Run would be applied is when a standby
pump is infrequently used; the test run would allow lubrication of bearings and help verify if
the unit is ready for operation. The TEST RUN DELAY sets the interval that automatic test runs
will occur at.
Test runs are factory programmed for 20 seconds. This duration cannot be changed. If
Automatic test run is selected, the test run is at 50% of maximum speed.
NOTE: Once manual test is selected and the test is complete, parameter 12.03 will return
to NOT SEL.
Parameter Name Value/Range Note(s)
12.02 AUTO OFF (Default) Must be set to ON for test run function to
RESTART ON operate.
12.03 TEST RUN NOT SEL (default)
AUTOMATIC
MANUAL
12.04 TEST SPEED 0-100% The speed, as a percent of maximum speed,
% (FL) 50% (Default) which the test run will occur at if MANUAL is
selected.
12.05 TEST RUN 0-3600 hours This is the period of pump inactivity before the
DELAY 1000 Hrs (Default) test run will begin, based on power up time.
Tuning, System Pressure
If the pump appears to oscillate in speed [e.g. Hunting], cannot maintain a uniform set point,
or shuts off too quickly or too slowly, the ramp rates and regulation window settings may need
to be modified, or adjustments.
When an operating mode is selected [i.e. Flow, Pressure, Level, etc…], Aquavar engages
factory default settings for the rate that the drive adjusts at to meet the set point demand.
In most cases these settings will not require adjustment. The most common exceptions are
with process instruments with slow response times [e.g. insertion type flowmeter
1 ], or in
temperature/level control applications, where variables such as tank size is unknown. HVAC
Systems with flow meters may require adjustment as well.
When the Aquavar system is adjusting speed to meet the set-point demand, it does so using
a fast rate and a slow rate. As shown in the figure below, the 2-point control algorithm uses
four ramp rates; fast acceleration, fast deceleration, slow acceleration, and slow deceleration.
Aquavar characterizes these rates in terms of seconds to meet the set point hysteresis window
maximum value (described later).
NOTE: In speed control mode, there is only fast acceleration and fast deceleration [R1, R2].
1 An insertion-type flowmeter uses a magnetic flux/Coriolis effect to measure fluid flow. This should not be confused with magnet flow meters
or differential pressure flow meters.
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