VLT
®
8000 AQUA
Programming
time. The Initial Ramp is used to quickly accelerate the
motor/equipment to minimum speed at which point,
the normal Ramp-Up rate (parameter 206) is made
active. The range of adjustment of the Initial Ramp
is from 000.1 second to 360.0 seconds; adjustable
in 0.1 second increments. If this parameter is set to
000.0, OFF is displayed in this parameter, the Initial
Ramp is not active, and the normal Ramp-Up is active.
■
Fill Mode
Fill Mode eliminates the occurrence of water hammer
associated with the rapid exhausting of air from
piping systems (such as Irrigation systems).
The AFD, set for Closed Loop operation uses an
adjustable Fill Rate, a "Filled Pressure" setpoint, an
operating pressure setpoint, and a pressure feedback.
Fill Mode is available when:
•
The VLT 8000 AQUA drive is in
Closed
Loop
mode (parameter 100).
•
Parameter 230 is
not 0
•
Parameter 420 is set to
NORMAL
After a start command, Fill Mode operation
begins when the AFD reaches minimum frequency
- set in parameter 201.
The "Filled" Setpoint - parameter 231 - is actually a
setpoint limit. When minimum speed is reached, the
pressure feedback is looked at, and the AFD begins
to ramp to the "Filled" pressure setpoint at the rate
established by Fill Rate parameter 230.
The Fill Rate - parameter 230 - is dimensioned
in Units/Second. The Units will be the units
selected in parameter 415.
When the pressure feedback equals the "Filled"
Setpoint, the control transitions to the operating
setpoint (Setpoint 1 - param. 418 or Setpoint
2 - param. 419 ) and continues operation in
standard (normal) "closed loop" mode.
The value to use for the "Filled" Setpoint parameter
231, can be determined by:
1. Use the DISPLAY MODE key on the LCP
to display
FEEDBACK 1
.
IMPORTANT!
Be sure that you have selected the
UNITS in parameter 415 before this step.
2. Operate the VLT 8000 AQUA 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 before starting).
5. The value of feedback in step 4) is the value to
use in parameter 231 - "Filled" Setpoint.
The value to set in parameter 230 - Fill Rate can
be supplied by the system engineer from proper
calculation or from experience, or it can be determined
experimentally by performing numerous fill mode
sequences and either increasing or decreasing
the value of this parameter to obtain the fastest
fill without causing a water hammer.
The
Fill Mode
is also beneficial when bringing the motor
to a stop as it prevents sudden changes in pressure
and flow which could also cause a water hammer.
230 Fill Rate
(FILL RATE)
Value:
OFF/000000.001 - 999999.999 (units/s) -
✭
OFF
Function:
Establishes the rate at which the pipe is filled.
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.80.A7.22 - VLT is a registered Danfoss trademark
111
Rosewood STP ST42 General (Operation and Maintenance Manual - Part 4:
Section 6.3 Manufacturers Manuals 6.3.33 Danfoss VLT Aquadrive 8000) Vendor Manual
QP Id: VM207
Active: 03/09/2013
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