88 GC250 Technical Manual
EAAM057608EN
Band G:
high
xxx
V
.
If the frequency is within the bands “B” or ”D”, previous status is maintained (hysteresis). For
example, in case the voltage was within th
e “C” band and is now within the “D” band, it is
anyway considered “In tolerance”. On the other hand, in case the frequency was within the “C”
band, and now is within “D” band, it is considered “Low”.
9.2.1.2
Mains voltages control
To disable this check, one of the following conditions shall be true:
▪
P.0203 = 0 %.
▪
P.0204 = 200 %.
▪
P.0203 >= P.0204
Let us see a practical example upon how thresholds work, with default values for the
parameters we have seen.
Parameter
Description
Default value
Voltage (Volt)
P.0116
Rated voltage
400 V
400
-
Mains presence threshold
20.0 %
80
P.0203
Minimum voltage threshold
80.0 %
320
P.0204
Maximum voltage threshold
110.0 %
440
P.0201
Maximum hysteresis
2.5 %
10
The hysteresis on the various thresholds is calculated as half the difference between P.0204
and P.0203. However, it is limited by the maximum value set with parameter P.0201. The
hysteresis applies to:
▪
Downwards, to mains availability threshold (i.e., between 70 V and 80 V).
▪
Upwards, to the minimum voltage threshold (i.e., between 320 V and 330 V).
▪
Downwards to the maximum voltage threshold (i.e., between 430 V and 440 V).
These values define the following bands:
0
V
.
Band A:
absent
70 (80-10)
V
.
Band B: hysteresis
80
V
.
Band C:
low
320
V
.
Band D: hysteresis
330 (320+10) V
.
Band E:
in tolerance
430 (440-10) V
.
Band F: hysteresis
440
V
.
Band G:
high
xxx
V
.
If the voltage is in the “B”,”D” or ”F” bands, previous status is maintained (hysteresis). For
example, if the
voltage was in the “E” band and now it is in “D” band, it is considered
however “In tolerance”. On the other hand, if it was in “C” band and now is in “D” band, it is
considered “Low”.
