EAAM057608EN
GC250 Technical Manual 87
P.0204: high mains voltages threshold (percentage respect to P.0116); over this value
mains is considered anomalous.
P.0205: mains live delay. It is the time that the device waits after the mains voltage
and frequency values are back to the respective bands, due to a mains anomaly
before considering the mains presence.
P.0206: mains live delay. It is the time that the device waits before considering the
mains as absent due to anomalies in the measures of voltage and frequency.
P.0236: low mains frequency threshold (percentage respect to P.0105); under this
value mains is considered anomalous.
P.0237: high mains frequency threshold (percentage respect to P.0105); over this
value mains is considered anomalous.
P.0238: mains voltages asymmetry threshold (percentage of P.0116); (over this value,
mains is considered anomalous). Used in three-phase system only.
P.0239: Rotation direction required for mains voltage. Used in three-phase system
only.
In order to assess the mains status, the controller can perform up to four different checks that
can be individually disabled. They are described individually below (also with examples):
remember that disabling both voltages and frequency checks is not possible (in this case,
mains is always considered not present).
9.2.1.1
Mains frequency control
To disable this check, one of the following conditions shall be true:
▪
P.0236 = 0 %.
▪
P.0237 = 200 %.
▪
P.0236 >= P.0237
Let us see a practical example upon how thresholds work, with default values for the
parameters we have seen.
Parameter
Description
Default value
Frequency (Hz)
P.0105
Rated frequency
50 Hz
50.00
P.0236
Minimum frequency threshold
90.0 %
45.00
P.0237
Maximum frequency
threshold
110.0 %
55.00
P.0201
Maximum hysteresis
2.5 %
1.25
The hysteresis on the various thresholds is calculated as half the difference between P.0237
and P.0236. However, it is limited by the maximum value set with parameter P.0201. The
hysteresis applies to:
▪
Upwards, to the minimum frequency threshold (i.e., between 45.00 and 46.25 Hz).
▪
Downwards to the maximum frequency threshold (i.e., between 53.75 Hz and 55.00
Hz).
These values define the following bands:
0.00
V
.
Band A:
low
45.00
V
.
Band B: hysteresis
46.25 (45.00 + 1.25)
V
.
Band C:
in tolerance
53.75 (55.00 + 1.25)
V
.
Band D: hysteresis
55.00
V
.
