Danfoss VLT AQUA Drive FC 200 Programming Manual page 183

Parameter Description
29-04 Pipe Fill Rate
Range:
3 3
29-05 Filled Setpoint
Range:
0.000
ProcessCtrlUnit
29-06 No-Flow Disable Timer
Range:
0.00 s
*
3.24.3 29-1* Deragging Function
The purpose of the deragging feature is to free the pump
blade of debris in waste water applications so that the
pump operates normally.
A deragging event is defined as the time when the
frequency converter starts to derag to when the deragging
finishes. When a derag is started, the frequency converter
ramps first to a stop and then an Off Delay expires before
the first cycle begins.
182
Function:
filling-up vertical pipe
systems but will be active
when the filling-time has
expired, no matter what ,
until the pipe fill-set-point
set in 29-05 Filled Setpoint
is reached.
Function:
[-999999.999 - Specifies the Filled Set-
999999.999 point at which the Pipe
*
ProcessCtrlUnit] Fill Function will be
disabled and the PID
controller will take
control. This function can
be used both for
horizontal and vertical
pipe systems.
[0.00 - 3600.00 s]
MG20O602 - VLT
®
VLT AQUA Drive Programming Guide
Speed
+/- Derag
Speed:
Par.: 29 -13
Par.: 29 -14
0 Hz / RPM
Illustration 3.83 Derag Function
Function:
If a derag is triggered from a drive stopped state, the first
Off Delay is skipped. The deragging event may consist of
several cycles; one cycle consists of one pulse in the
reverse direction followed by one pulse in the forward
direction. Deragging is considered finished after the
specified number of cycles has completed. More specif-
ically, on the last pulse (it will always be forward) of the
last cycle, the derag is considered finished after the
Deragging Run Time expires (the frequency converter will
be running at Derag Speed). In between pulses, the
frequency converter output coasts for a specified Off Delay
time to let debris in the pump settle.
NOTE
Do not enable deragging if the pump cannot operate in
reverse direction.
There are three different notifications for an ongoing
deragging event:
•
•
•
Depending on the application and on the purpose of using
it, this feature can be used as preventative or reactive
measure and can be triggered/started in the following
different ways:
®
is a registered Danfoss trademark
Derag
function
activated
Derag O Delay:
Par. 29 -15
Deragging Run Time : Par . 29-12
1 Cycle
Number of Cycles : Par . 29 -10
Status in the LCP: "Auto Remote Derag"
A bit in the Extended Status Word (Bit 23 , 80
0000 hex)
A digital output can be configured to reflect the
active deragging status.