Xylem IM043 AQUAVAR Variable Speed Pump Control - Manual (Page 56)

Ramp 1
This ramp is the fast run up time used when the pump first comes on and is trying to reach the
set point. The normal set point for this ramp is 4 seconds for the horse power range 2 through 15
hp. For versions with higher horsepowers, 20 hp and above, the setting should be 10 seconds
minimum. A setting which is too fast may overload the inverter. A setting which is too slow tends
to cause uneven outgoing pressure (pressure drops).
Ramp 2
This ramp is the fast run down time used when the pump is shutting down after demand has
ended. The normal set point for this ramp is 4 seconds for the horse power range 2 through 15
hp. For versions with higher horsepowers, 20 hp and above, the setting should be 10 seconds
minimum. A setting which is too fast leads to pump oscillation or hunting. A setting which is too
slow tends to generate overpressure. Note: air in the pump system can cause a
condition which looks like hunting. Please be sure all air is purged from the system
before trying to change ramp 2.
Ramp 3
This ramp is the slow run up time used when the pump is operating within its set point window
as described above. The normal setting is 50 seconds. A setting which is too slow may cause the
outgoing pressure to drop when demand varies. A setting which is too fast may lead to over
oscillation and inverter overload.
Ramp 4
This ramp is the slow run down time used when the pump is operating within its set point
window. The normal setting is 50 seconds. A setting which is too slow leads to oscillation. A setting
which is too fast delays motor shut down after demand is over.
Maximum Frequency
This setting should match the requirements of the motor being used. If the motor being used is a
60 hz motor, the setting should be 60 hz. If the motor is 50 hz, change this setting to 50 hz.
55
Operator Custom Features and Displays
PRESSURE
R1
R3 R4
R1
R3
R2
R4
R3
R4
SET HYSTERESIS %
SET HYSTERESIS %
100%
SET RATED
PRESSURE
WINDOW
SETTING IN % OF
RATED PRESSURE
R1: SPEED RAMP FAST INCREASE
R2: SPEED RAMP FAST DECREASE
R3: SPEED RAMP SLOW INCREASE
R4: SPEED RAMP SLOW DECREASE
Diagram 18
It is possible to set this frequency up to 70 hz. This is not recommended for
standard pumps. A 10% increase in frequency causes 33% more power draw.
Note