Danfoss VLT AutomationDrive FC 301 Programming Manual page 176

Parameter Descriptions
3.14.7 14-6* Auto Derate
This group contains parameters for derating the frequency
converter in case of high temperature.
14-60 Function at Over Temperature
3 3
Option:
[0] Trip
*
[1] Derate If the critical temperature is exceeded, the output
3.14.8 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.
Current
% of rated
110
105
100
95
Inverter
load
counter
100
98
90.7
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.
174
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.
The frequency converter trips (trip lock) and
generate an alarm. Cycle power to reset the alarm.
The motor restarts when the heat sink temperature
has dropped below the alarm limit.
current is reduced until the allowable temperature
has been reached.
~ ~
60s
Desired current>100%
Warning Warning
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®
VLT AutomationDrive FC 301/302
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 issue 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.
14-61 Function at Inverter Overload
Option:
[0] Trip
*
[1] Derate Reduces the motor speed to decrease the load on
14-62 Inv. Overload Derate Current
Range:
95 %
*
100 %]
Time
3.14.9 14-7* Compatibility
Parameters for compatibility of VLT 3000 and VLT 5000
with FC 300.
14-72 VLT Alarm Word
Time
Option:
[0] 0 - 4294967295 Readout of the alarm word corresponding to
14-73 VLT Warning Word
Option:
[0] 0 - 4294967295 Readout of the warning word corresponding
Function:
Use in case of steady overload beyond the thermal
limits (110% for 60 s).
Select [0] Trip to make the frequency converter trip
and issue an alarm.
the power section and allowing it to cool down.
Function:
[50 - Enter the current level (in % of rated output
current for the frequency converter) when
running with reduced motor speed after load
on the frequency converter has exceeded the
allowable limit (110% for 60 s).
Function:
VLT 5000.
Function:
to VLT 5000.
MG33MO02