Danfoss VLT Series Programming Manual page 114

Parameter Description
Current
% of rated
110
105
100
95
~ ~
60s
Desired current>100%
Inverter
load
counter
100
98
90.7
Warning
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 Function at Inverter Overload, 14-61 Function at
Inverter Overload to automatically reduce pump speed until
the output current is below 100% of the rated current (set
in 14-62 Inv. Overload Derate Current).
The 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 16-35 Inverter
Thermal.
If 14-61 Function at Inverter Overload is set to 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 Trip [0] to make the frequency converter
*
trip and provide an alarm.
[1] Derate Derate [1] to reduce pump speed in order to
decrease the load on the power section and
allowing this to cool down.
®
VLT HVAC Drive Programming Guide
Time
Time
Warning
®
MG.11.CC.02 - VLT is a registered Danfoss trademark
14-62 Inv. Overload Derate Current
Range: Function:
95 % [50 - 100 Defines the desired current level (in % of
*
%] rated output current for the frequency
converter) when running with reduced
pump speed after load on the frequency
converter has exceeded the allowable limit
(110% for 60 sec.).
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