Danfoss VLT AQUA Drive FC 202 Programming Manual page 189

Parameter Description
22-61 Broken Belt Torque
Range: Function:
10 % [0 - 100 %] Sets the broken-belt torque as a percentage
*
of the rated motor torque.
22-62 Broken Belt Delay
Range: Function:
10 s [0 - 600 Sets the time for which the broken belt
s] conditions must be active before carrying out
the action selected in parameter 22-60 Broken
Belt Function.
3.19.7 22-7* Short Cycle Protection
In some applications, a need for limiting the numbers of
starts often exists. One way to do this is to ensure a
minimum run time (time between a start and a stop) and a
minimum interval between starts.
This means that any normal stop command can be
overridden by parameter 22-77 Minimum Run Time and any
normal start command (start/jog/freeze) can be overridden
by parameter 22-76 Interval between Starts.
None of the 2 functions are active if hand-on mode or off
mode have been activated via the LCP. If pressing [Hand
On] or [Off], the 2 timers are reset to 0 and do not start
counting until [Auto On] is pressed, and an active start
command is applied.
22-75 Short Cycle Protection
Option: Function:
[0] Disabled Timer set in parameter 22-76 Interval between
*
Starts is disabled.
[1] Enabled Timer set in parameter 22-76 Interval between
Starts is enabled.
22-76 Interval between Starts
Range: Function:
Size related [ par. 22-77 - Sets the minimum time between 2
*
3600 s] starts. Any normal start command
(start/jog/freeze) is disregarded
until the timer has expired.
22-77 Minimum Run Time
Range: Function:
NOTICE
0 s [ 0 - par.
*
22-76 s]
Does not work in cascade mode.
Sets the minimum run time after a normal start
command (start/jog/freeze). Any normal stop
command is disregarded until the set time has
MG20OB02
Programming Guide
22-77 Minimum Run Time
Range:
22-78 Minimum Run Time Override
Option:
[0]
*
[1]
22-79 Minimum Run Time Override Value
Range:
0 ProcessCtrlUnit
3.19.8 22-8* Flow Compensation
In certain applications, it is not possible for a pressure
transducer to be placed at a remote point in the system,
and it can only be located close to the fan/pump outlet.
Flow compensation operates by adjusting the setpoint
according to the output frequency, which is almost propor-
tional to flow. Thus, it compensates for higher losses at
higher flow rates.
H (required pressure) is the setpoint for closed-loop
DESIGN
(PI) operation of the frequency converter and is set as for
closed-loop operation without flow compensation.
Illustration 3.70 Flow Compensation Set-up
There are 2 methods which can be employed, depending
on whether the speed at system design working point is
known.
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Function:
expired. The timer starts counting following a
normal start command (start/jog/freeze).
A coast (inverse) or an external interlock
command overrides the timer.
Function:
Disabled
Enabled
[-999999.999 - 999999.999
*
ProcessCtrlUnit]
3 3
Function:
187