22-82 Work Point Calculation
Option:
Function:
pressure H
DESIGN
at that flow can be determined.
Knowing these 2 points on the pump curve, along
with H
MIN
as described above, allows the
frequency converter to calculate the reference
point B and thus to plot the control curve, which
also includes the system design working point A.
Set point
Control Curve
n
DE
SIG
N
-f
D
ES
IG
N
n
RA
TE
D
-f
RA
TE
D
(head)
H
H
RATED
Par.
22-88
Q
DESIGN
Par.
22-89
H
MIN
D
B
C
A
Q
RATED
Par.
22-90
(flow)
Q
H
DESIGN
130BA387.11
22-84/
22-87
22-83/
Par.:
Illustration 4.23 Speed at System Design
Working Point is not Known
[0]
*
Disabled Work point calculation not active. To be used if
speed at design point is known.
[1] Enabled Work point calculation is active. Enabling this
parameter allows the calculation of the unknown
system design working point at 50/60 Hz speed,
from the input data set in:
•
Parameter 22-83 Speed at No-Flow [RPM]
.
•
Parameter 22-84 Speed at No-Flow [Hz]
.
•
Parameter 22-87 Pressure at No-Flow
Speed
.
•
Parameter 22-88 Pressure at Rated Speed
.
•
Parameter 22-89 Flow at Design Point
•
Parameter 22-90 Flow at Rated Speed
22-84 Speed at No-Flow [Hz]
Range:
Function:
0 Hz
*
[ 0 -
400.0
Hz]
Resolution 0.033 Hz.
Enter the motor speed in Hz at which flow has
effectively stopped and minimum pressure H
MIN
is achieved. Alternatively, enter the speed in
RPM in
parameter 22-83 Speed at No-Flow [RPM]
.
If it has been decided to use Hz in
parameter 0-02 Motor Speed Unit
,
parameter 22-86 Speed at Design Point [Hz]
should also be used. Closing the valves and
reducing the speed until minimum pressure
H
MIN
is achieved determines this value.
22-86 Speed at Design Point [Hz]
Range:
Function:
Size
related
*
[ 0.0 -
400.0
Hz]
Resolution 0.033 Hz.
Only visible when
is set to
[0] Disabled
. Enter
the motor speed in Hz at which the system
design working point is achieved. Alterna-
tively, enter the speed in RPM in
parameter 22-85 Speed at Design Point [RPM]
.
If it has been decided to use Hz in
parameter 0-02 Motor Speed Unit
,
parameter 22-83 Speed at No-Flow [RPM]
should also be used.
22-87 Pressure at No-Flow Speed
Range:
Function:
0
*
[ 0 - 999999.999 ] Enter the pressure H
MIN
corresponding to
speed at no-flow in reference/feedback
units.
22-88 Pressure at Rated Speed
Range:
Function:
999999.999
*
[ 0 -
999999.999 ]
Enter the value corresponding to
the pressure at rated speed, in
reference/feedback units. This
value can be defined using the
pump datasheet.
See
parameter 22-88 Pressure at Rated Speed
point A.
22-89 Flow at Design Point
Range:
Function:
0
*
[0 - 999999.999 ]
Flow at design point (no units).
22-90 Flow at Rated Speed
Also see
parameter 22-82 Work Point Calculation
.
Range:
Function:
0
*
[0 - 999999.999 ] Enter the value corresponding to flow at
rated speed. This value can be defined
using the pump datasheet.
Parameters
VLT
®
DriveMotor FCP 106/FCM 106
112
Danfoss A/S © 11/2015 All rights reserved.
MG03N202
4
4