P.21 - Overload threshold for immediate step disconnection
When the measured overload exceeds the value set at P.21 , the capacitors are immedi-
ately disconnected and the capacitor overload alarm A07 is generated.
Note: The delay time of Capacitor overload alarm A07 operates inversely proportional to
the overload entity, compared to the programmed thresholds of P.20 and P.21. When the
overload is lower than the P.20 threshold, the alarm will not be generated. When the over-
load is equal to P.20, the delay time is equal to the one set for the alarm (3 minutes by
default but can be changed via the PC). As the overload increases, the delay time be-
comes proportionally less until it attains zero once the value set to P.21 is reached. With
P.20 at OFF, there is no tripping until the value P.21 is exceeded and the immediate dis-
connection of the steps takes place.
With P.21 at OFF, the delay TIME is also constant. With P.20 and P.21 both at OFF, the
capacitor overload measurement is disabled as well as the alarm A07. In these condi-
tions, the display indicates --- instead of the overload measurement. Whenever the ca-
pacitor banks are equipped with inductances to prevent harmonic overload, P.20 and
P.21 must be at OFF .
P.22 - Overload event counter clear time
Each time an A07 Capacitor overload alarm is generated, the event is registered by an
internal counter, which can be consulted by pressing the + key when the OVERLOAD %
LED is lit up. The counter indicates the number of capacitor overload events that have
taken place over the time period defined by P.22. This parameter also defines the number
of hours during which the events remain stored. If no event has taken place during the set
time period, the counter is cleared.
P.23 - Overload alarm reset time
Time period during which the A07 Capacitor overload alarm remains active even though
the overload value has decreased below the alarm thresholds.
P.24 - Unit of measure for temperature
This defines the unit of measurement, in degrees Celsius or Fahrenheit, for displaying the
temperature and the threshold settings related to it.
P.25 -Fan start temperature
Sets the temperature above which the fan relay is activated (if programmed in one of the
last two steps).
P.26 -Fan stop temperature
Sets the temperature below which the fan relay is disactivated (if programmed in one of
the last two steps).
P.27 - Temperature alarm threshold
Sets the temperature above which the Temperature too high alarm A08 is activated.
1.21 ALARMS
When the controller detects an abnormal situation in the system, a flashing alarm code is
displayed. By pressing any key, display of the alarm will be momentarily ignored to allow
the user to check all the measurements. If no key is pressed for 30 seconds and the
alarm conditions persist, the alarm code will be displayed once again.
Each alarm can cause diverse results such as the alarm relay tripping, the delayed or
immediate step disconnection, etc., according to the programmed property. The property
of each alarm can be changed (e.g. disabled, change the delay time or effect), by using a
PC and the relative software (order code A25060000000045), used for the quick parame-
ter set-up.
The following table indicates the alarm codes and the relative meaning of each along with
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