GE Ecomagination AF-600 FP Programming Manual page 137

Parameter Description
3 3
Illustration 3.46 Square-Linear Curve Approximation
AP-82 Work Point Calculation
Option:
136
Function:
Example 1
Illustration 3.47 Speed at System Design
Working Point is Known
From the datasheet showing characteristics for the
specific equipment at different speeds, simply
reading across from the H point and the
DESIGN
Q point allows finding point A, which is the
DESIGN
system design working point. The pump character-
istics at this point should be identified and the
associated speed programmed. Closing the valves
and adjusting the speed until H
MIN
achieved allows the speed at the no-flow point to
be identified.
Adjustment of parameter AP-81 Square-linear Curve
Approximation then allows the shape of the
control curve to be adjusted infinitely.
Example 2
Speed at system design working point is not
known: Where the speed at system design
working point is unknown, another reference point
on the control curve needs to be determined
based on the datasheet. By looking at the curve
for the rated speed and plotting the design
pressure (H , Point C), the flow at that
DESIGN
pressure, Q , can be determined. Similarly, by
RATED
plotting the design flow (Q , Point D), the
DESIGN
pressure H at that flow can be determined.
DESIGN
Knowing these 2 points on the pump curve, along
with H as described above, allows the
MIN
frequency converter to calculate the reference
point B and thus to plot the control curve, which
also includes the system design working point A.
AP-82 Work Point Calculation
Option:
[0] Disabled Work point calculation not active. To be used if
*
[1] Enabled Work point calculation is active. Enabling this
AP-83 Speed at No-Flow [RPM]
Range:
300
RPM AP-85
*
RPM]
has been
AP-84 Speed at No-Flow [Hz]
Range:
50.0 [0 - par.
Hz AP-86
*
Hz]
03/2016 All rights reserved.
Function:
Illustration 3.48 Speed at System Design
Working Point is not Known
speed at design point is known.
parameter allows the calculation of the unknown
system design working point at 50/60 Hz speed,
from the input data set in:
•
Parameter AP-83 Speed at No-Flow [RPM].
•
Parameter AP-84 Speed at No-Flow [Hz].
•
Parameter AP-87 Pressure at No-Flow
Speed.
•
Parameter AP-88 Pressure at Rated Speed.
•
Parameter AP-89 Flow at Design Point.
•
Parameter AP-90 Flow at Rated Speed.
Function:
[0 - par. Resolution 1 RPM.
Enter the speed of the motor in RPM at
which flow is 0 and minimum pressure H
achieved. Alternatively, enter the speed in Hz
in parameter AP-84 Speed at No-Flow [Hz]. If it
has been decided to use RPM in
parameter K-02 Motor Speed Unit,
parameter AP-85 Speed at Design Point [RPM]
should also be used. Closing the valves and
reducing the speed until minimum pressure
H is achieved determines this value.
MIN
Function:
Resolution 0.033 Hz.
Enter the motor speed in Hz at which flow has
effectively stopped and minimum pressure
H is achieved. Alternatively, enter the speed
MIN
in RPM in parameter AP-83 Speed at No-Flow
[RPM]. If it has been decided to use Hz in
parameter K-02 Motor Speed Unit,
parameter AP-86 Speed at Design Point [Hz]
should also be used. Closing the valves and
reducing the speed until minimum pressure
H is achieved determines this value.
MIN
is
MIN
DET-620D