57 |
P a g e
Pressure Control at Minimum Speed
There is a possibility of conflict between the minimum pump speed setting, controlled by the parameter
MIN FREQUENCY
, and the pressure setting of the transducer. That is, if under no-flow conditions the
pump at its minimum speed setting produces a pressure greater than the desired set-point, either the
minimum speed will have to be reduced (not an option with submersible pumps) or the pressure set-
point will have to be increased. Most pumps should not produce enough pressure head at 30 Hz for this
to be an issue.
Boost in a Digital Constant Pressure System
In a digital CP system the drive can only determine the pressure of the system at the set-point. Based
on the characteristics of the on/off signals from the switch, which occur at the set-point, it maintains
pressure. The parameter
BOOST
AMOUNT
in a digital system is a percent increase in speed, not in
pressure, because the digital switch cannot determine a pressure beyond its set-point.
In an analog system the
BOOST
AMOUNT
is a specified psi, so the user can accurately control the
boost pressure through the parameter setting on the keypad. For example, if boost of 5 psi above
control pressure is desired, simply set parameter
BOOST
AMOUNT
to 5.
In a digital system
BOOST
AMOUNT
is an increase in speed for a given time as a percent of the speed
the pump was running when the switch last opened at the set-point. For example, if pressure is
controlled at a speed of 30 Hz, a
BOOST
AMOUNT
value of 10 would be 10% of 30 Hz or 3 Hz. In low
flow systems where the pressure is controlled at low speed, the
BOOST
AMOUNT
value may need to
be significantly higher than it would be set in an analog system under the same conditions.
7.2
Perfect Pressure™
Setup
–
Analog Constant Pressure
Upon the first initialization of the unit (or after restoring factory defaults of all parameters using the Two
Button Reset Procedure, on page 36) the drive will prompt the user to select or decline a quick setup for
constant pressure. The display will read
SETUP CONST PRES YES(ENTER)/NO(HOME)
. Press the
ENTER key to set up
Perfect Pressure™ or the HOME key to decline. Basic parameters for analog
constant pressure can be set without navigating through the complete menu options.
Follow this procedure to set up
Perfect Pressure™:
1.
SETUP CONST PRES YES(ENTER)/NO(HOME)
- Press the ENTER key to proceed.
2.
4-20mA psi RANGE
- This parameter sets the range of the 4-20mA pressure sensor. The
factory default is 150 since the standard sensor provided by the factory has a maximum range
of 150 psi. If necessary, use the arrow keys to change the value, then press ENTER, or simply
press ENTER to proceed.
3.
psi SETPOINT -
This value determines the pressure you want to maintain. The factory default
is 50 psi. Use the arrow keys to change if desired. Press ENTER to proceed.
4.
SUBMERSIBLE PUMP
- This parameter sets the ramp profile for a submersible pump.
YES =
submersible pump, NO = vertical pump.
For submersible pumps the frequency accelerates
from 0-30 Hz in one second, then follows the ramp time from 30 Hz to maximum frequency. If
NO is selected the frequency will increase in a linear fashion from zero to max frequency.
Содержание 2XD Series
Страница 10: ...4 P a g e 2 3 Dimensional Drawings Figure 5 SD Series Line Drawing...
Страница 11: ...5 P a g e Figure 6 SD Series Line Drawing if selected with optional breaker see Figure 9...
Страница 12: ...6 P a g e Figure 7 SD Series Line Drawing if selected with optional breaker see Figure 9...
Страница 13: ...7 P a g e Figure 8 SD Series Line Drawing if selected with optional breaker see Figure 9 or Figure 10...
Страница 14: ...8 P a g e Figure 9 SD Series Line Drawing...
Страница 15: ...9 P a g e Figure 10 SD Series Line Drawing...
Страница 16: ...10 P a g e Figure 11 2XD Series Line Drawing...
Страница 80: ...74 P a g e Figure 36 SW1 in SD Systems...
