Sices HS 315, Техническое руководство

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120 Technical Handbook
Here follows an example about the various threshold used, including default values for a.m.
parameters.
Parameter Description Default value Voltage in Volts
P.0116 Nominal voltage (AC) of the
auxiliary source. 400 V 400
- Auxiliary source presence
threshold 20.0 % 80
P.0203 Auxiliary source low voltage
threshold. 80.0 % 320
P.0204 Auxiliary source high voltage
threshold. 110.0 % 440
P.0201 Hysteresis for auxiliary
source measures.
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 auxiliary source 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 .
A band: absent
70 (80-10) V .
B band: hysteresis
80 V .
C band: low
320 V .
D band: hysteresis
330 (320+10) V .
E band: in tolerance
430 (440-10) V .
F band: hysteresis
440 V .
G band: 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 contrary, if voltage was in the “C” band and now is in “D” band, it is
considered
“Low”.
In single-phase systems, these tests are executed on phase-to-neutral voltage.
In Three-phases systems, these tests are executed on all phase-to-phase voltages. If the
neutral is connected to the terminal JH-4 (P.9618 =
“018”), these tests are executed on the
three phase-to-neutral voltages too.
The DC voltage of the auxiliary source can be connected to terminals JH, JG or JQ (see 5.13).
To detect the status, normally the controller cannot use the DC voltage of the auxiliary source
if it is connected to other active sources, like the generator or the plant battery. In this case, in
fact, the measured voltage is an “average” of those connected. It is possible to by-pass the
problem in three ways:
•
Using an external sensor connected to a digital input of the controller (see the following
chapters).