Danfoss VLT 2800 Series Operating Instructions Manual page 58

The "Filled" Setpoint - parameter 486- is actually a
setpoint limit. When minimum speed is reached, the
pressure feedback is looked at, and the frequency
converter begins to ramp to the "Filled" pressure set-
point at the rate established by Fill Rate parameter
485.
The Fill Rate - parameter 485- is dimensioned in Units/
Second. The Units will be the units selected in param-
eter 416.
When the pressure feedback equals the "Filled" Set-
point, the control transitions to the operating setpoint
(Setpoint 1-4, param. 215-218) and continues opera-
tion in standard (normal) "closed loop" mode.
The value to use for the "Filled" Setpoint parameter
486, can be determined by:
1. Use the DISPLAY MODE key on the LCP to
display FEEDBACK 1.
IMPORTANT! Be sure that you have selec-
ted the UNITS in parameter 416 before this
step.
2.
Operate the VLT 2800 in HAND mode and
slowly advance the speed to fill the pipe while
being careful not to create a water hammer.
3. An observer at the end of the pipe must be
able to report when the pipe is filled.
4. At that instant, stop the motor, and observe
the value of pressure feedback (have the
LCP display set to observe the feedback be-
fore starting).
5. The value of feedback in step 4) is the value
to use in parameter 486 - "Filled" Setpoint.
The value to set in parameter 485- Fill Rate can be
supplied by the system engineer from proper calcula-
tion or from experience, or it can be determined ex-
perimentally by performing numerous fill mode se-
quences and either increasing or decreasing the value
of this parameter to obtain the fastest fill without caus-
ing a water hammer.
The Fill Mode is also beneficial when bringing the mo-
tor to a stop as it prevents sudden changes in pressure
and flow which could also cause a water hammer.
= factory setting, () = display text, [] = value for use in communication via serial communication port
®
MG.27.A2.02 - VLT is a registered Danfoss trademark
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VLT 2800 Series
485 Fill Rate
(FILL RATE)
Value:
OFF/000000.001 - 999999.999 (units/s) -
Function:
Establishes the rate at which the pipe is filled.
Description of choice:
The dimension of this parameter is Units/Second. The
Units will be the value selected in parameter 416. As
an example, the Units could be Bar, or MPa, or PSI,
etc. If Bar is the selected unit in parameter 416, then
the number set in this parameter (485) would be di-
mensioned as Bar/Second. Changes to this parameter
can be made in steps of .001 units.
486 Filled Setpoint
(FILLED SETPOINT)
Value:
Param. 414 - Param. 205 -
Function:
The value set in this parameter corresponds to the
pressure that exists at the pressure sensor when the
pipe is filled.
Description of choice:
The Units of this parameter correspond to the units
selected in Parameter 416. The minimum value of this
parameter is Fb (param. 414). The maximum value
min
for this parameter is Ref
max
can be changed in .01 steps.
OFF
Param. 414
(param. 205). The setpoint
57