14-56 Capacitance Output Filter
Compensation function of the LC filter requires the per phase
equivalent star-connected capacitance of the filter (3 times the
capacity between 2 phases when capacitance is delta
connection).
Range:
Function:
NOTICE
This is required for correct
compensation in flux mode
(
14-57 Inductance Output Filter
Range:
Function:
Size
related
*
[0.001 -
65 mH]
Set the inductance of the output filter.
The value can be found on the filter
label.
NOTICE
This is required for correct
compensation in flux control
principle (
14-59 Actual Number of Inverter Units
Range:
Function:
Size related
*
[ 1 - 1 ] Set the actual number of power units.
3.14.6 14-6* Auto Derate
This group contains parameters for derating the frequency
converter if there is high temperature.
14-60 Function at Over Temperature
Option:
Function:
If either heat sink or control card temperature
exceeds a factory-programmed temperature limit, a
warning is activated. If the temperature increases
further, select whether the frequency converter
should trip (trip lock) or derate the output current.
[0]
*
Trip
The frequency converter trips (trip lock) and
generates an alarm. Cycle power to reset the alarm.
The motor restarts when the heat sink temperature
has dropped below the alarm limit.
[1]
Derate If the critical temperature is exceeded, the output
current is reduced until the allowable temperature
has been reached.
3.14.7 No Trip at Inverter Overload
In some systems, the frequency converter has not been
sized properly to yield the current needed in all points of
the operational flow-head characteristic. At these points,
the motor needs a current higher than the rated current of
the frequency converter. The frequency converter can yield
110% of the rated current continuously for 60 s. If still
overloaded, the frequency converter normally trips
(causing the motor to stop by coasting) and issues an
alarm.
110
130BA260.10
105
100
95
60s
100
90.7
98
Current
% of rated
Time
Desired current>100%
Inverter
load
counter
Time
Warning
Warning
~
~
Illustration 3.64 Output Current in Overload Condition
If the motor is unable to run continuously with the
demanded capacity, run it at reduced speed for a while.
Select
parameter 14-61 Function at Inverter Overload
to
automatically reduce motor speed until the output current
is below 100% of the rated current (set in
parameter 14-62 Inv. Overload Derate Current
).
Parameter 14-61 Function at Inverter Overload
is an
alternative to letting the frequency converter trip.
The frequency converter estimates the load on the power
section with an inverter load counter, which causes a
warning at 98% and a reset of the warning at 90%. At the
value 100%, the frequency converter trips and issues an
alarm.
Status for the counter can be read in
parameter 16-35 Inverter Thermal
.
If
parameter 14-61 Function at Inverter Overload
is set to
[3]
Derate
, the motor speed is reduced when the counter
exceeds 98%, and stays reduced until the counter has
dropped below 90.7%.
If
parameter 14-62 Inv. Overload Derate Current
is set to for
example 95%, a steady overload causes the pump speed to
fluctuate between values corresponding to 110% and 95%
of rated output current for the frequency converter.
Parameter Descriptions
Programming Guide
MG33MP02
Danfoss A/S © 10/2018 All rights reserved.
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Summary of Contents for VLT AutomationDrive FC 302
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