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4
4.4 Basic Settings
63
Power Meter SICAM P 7KG7750/55, Manual
E50417-B1076-C340-A6, Edition 09.2013
Up to U
LN
= 480 V, the SICAM P can be connected directly without a transformer. In three- and
four-phase networks,
except for three-phase networks without neutral
(see the respective
notes), the SICAM P can also be connected directly without a transformer up to U
LL
= 690 V.
Caution
•
You must make these settings for a direct connection or for a connection with current trans-
formers.
•
The selected measuring range must be greater than the secondary rating of the voltage
transformer!
•
The accuracy of SICAM P is based on the selected measuring range.
•
The determination of this range indicates the maximum voltage value that can be displayed
on the device.
•
"The frequency measurement of the SICAM P is initiated only when the measured voltage is
> 30 % of the maximum voltage of the measuring range.
•
Measurements in three-phase networks without neutral in V-connection (1:1 transformer) are
possible
up to
a nominal voltage of U
LL
= 400 V. With this nominal voltage, the measuring
range U
LL
= 690 V
must
be parameterized.
•
For measurements in three-phase networks without neutral in V-connection and a nominal
voltage of U
LL
= 690 V, the voltage must be transformed to U
LL
≤
400 V. The measuring
range to be parameterized is then also U
LL
= 690 V.
•
In IT networks, the SICAM P cannot be connected directly because the voltage is measured
against the PE conductor connection and the input impedance of the device causes a leak-
age current against earth. The leakage current can cause tripping of the leakage protective
system in IT networks. Please make sure that the maximum permissible input voltage of the
SICAM P against earth U
L-PE
= 480 V is not exceeded (e.g., due to an earth fault of one
phase). Voltage transformers
must
be used in IT networks.
Selectable measuring range L-L
Equivalent to measuring range L-N
AC 0 V to 132 V
AC 0 V to 76.2 V
AC 0 V to 228 V
AC 0 V to 132 V
AC 0 V to 480 V
AC 0 V to 276 V
AC 0 V to 828 V
AC 0 V to 480 V