No Trip At Inverter Overload; Function At Over Temperature - Danfoss VLT Programming Manual

3 Parameter Description

14-60 Function at Over Temperature

Option:
[0] * Trip
3
[1] Derate

3.14.9 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 sec. If still overloaded, the frequency converter will normally trip (causing the pump to stop by coasting)
and provide an alarm.
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.
Function at Inverter Overload
Select
100% of the rated current (set in par. 14-62
Function at Inverter Overload
The
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 par. 16-35
Function at Inverter Overload
If par. 14-61
counter has dropped below 90.7.
If par. 14-62 Inv. Overload Derate Current
110% and 95% of rated output current for the frequency converter.
154
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 con-
verter should trip (trip locked) or derate the output current.
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.
If the critical temperature is exceeded the output current will be reduced until the allowable tem-
perature has been reached.
Function at Inverter Overload
, par. 14-61
Inv. Overload Derate Current
is an alternative to letting the frequency converter trip.
Inverter Thermal .
is set to Derate, the pump speed will be reduced when the counter exceeds 98, and stay reduced until the
is set e.g. to 95% a steady overload will cause the pump speed to fluctuate between values corresponding to
MG.11.C9.02 - VLT
VLT
to automatically reduce pump speed until the output current is below
).
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HVAC Drive Programming Guide