14-55 Output Filter
Option:
Function:
[0]
*
No
Filter
This is the default setting and should be used
with dU/dt filters or high-frequency common-
mode (HF-CM) filters.
[1]
Sine-
Wave
Filter
This setting is only for backwards compatibility. It
enables operation with FLUX control principle
when the parameters
14-56 Capacitance Output
Filter
and
14-57 Inductance Output Filter
are
programmed with the output filter capacitance
and inductance. It DOES NOT limit the range of
the switching frequency.
3.11.7 14-6* Auto Derate
This group contains parameters for derating the frequency
converter in case of high temperature.
14-60 Function at Over Temperature
Option:
Function:
If either heatsink or control card temperature
exceeds a factory-programmed temperature limit, a
warning will be activated. If the temperature
increases further, select whether the frequency
converter should trip (trip locked) or derate the
output current.
[0]
*
Trip
The frequency converter will trip (trip locked) and
generate an alarm. Power must be cycled to reset
the alarm, but will not allow restart of the motor
until the heat sink temperature has dropped below
the alarm limit.
[1]
Derate If the critical temperature is exceeded the output
current will be reduced until the allowable
temperature has been reached.
3.11.8 No Trip at Inverter Overload
In some pump 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 pump will need 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 will
normally trip (causing the pump to stop by coasting) and
provide 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 3.35
It may be preferable to run the pump at reduced speed for
a while in case it is not possible to run continuously with
demanded capacity.
Select
14-61 Function at Inverter Overload
to automatically
reduce pump speed until the output current is below
100% of the rated current (set in
).
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 by means of an inverter load counter, which will
cause a warning at 98% and a reset of the warning at 90%.
At the value 100%, the frequency converter trips and
provides an alarm.
Status for the counter can be read in
If
14-61 Function at Inverter Overload
is set to
[3] Derate
, the
pump speed will be reduced when the counter exceeds
98, and stay reduced until the counter has dropped below
90.7.
If
14-62 Inv. Overload Derate Current
is set e.g. to 95% a
steady overload will cause 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:
Function:
Is used in case of steady overload beyond the
thermal limits (110% for 60 sec.).
[0]
*
Trip
Choose
[0] Trip
to make the frequency converter
trip and provide an alarm.
[1]
Derate
[1] Derate
to reduce pump speed in order to
decrease the load on the power section and
allowing this to cool down.
Parameter Description
VLT
®
Refrigeration Drive Programming Guide
MG16H102 - VLT
®
is a registered Danfoss trademark
97
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