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Functions
2.1 General
2.1.6
Power System Data 2
Applications
• If the primary reference voltage and the primary reference current of the protected object are set, the device
is able to calculate and output the percentaged operational measured values.
• For utilization in motors, detection of a motor start represents an important feature. Exceeding a configured
current value serves as a criterion.
2.1.6.1 Description
The general protection data (P.System Data 2) includes parameters common to all functions, i.e. not asso-
ciated with a specific protection or monitoring function. In contrast to the P.System Data 1 as discussed
before, they can be changed with the parameter group.
2.1.6.2 Setting Notes
Definition of Nominal Rated Values
At addresses 1101 FullScaleVolt. and 1102 FullScaleCurr., the primary reference voltage (phase-
to-phase) and reference current (phase) of the protected equipment is entered (e.g. motors). If these reference
sizes match the primary nominal values of the VTs and CTs, they correspond to the settings in address 202
and 204 (Section 2.1.3.2). They are generally used to show values referenced to full scale.
Recognition of Running Condition (Only for Motors)
When the configured current value at Address 1107 I MOTOR START is exceeded, this will be interpreted as
motor starting. This parameter is used by the start-up time monitoring and overload protection functions.
For this setting the following should be considered:
• A setting must be selected that is lower than the actual motor start-up current under all load and voltage
conditions.
• During motor start-up the thermal replica of the overload protection is "frozen", i.e. kept at a constant level.
This threshold should not be set unnecessarily low since it limits the operating range of the overload protec-
tion for high currents during operation.
Inverting Power Measured Values/Metered Values
The directional values (power, power factor, work and related min., max., mean and setpoint values), calculated
in the operational measured values, are usually defined a positive in the direction of the protected object. This
requires that the connection polarity for the entire device was configured accordingly in the P.System Data
1 (compare also "Polarity of the Current Transformers", address 201). But it is also possible to make different
settings for the "forward" direction" for the protection functions and the positive direction for the power etc., e.g.
to have the active power supply (from the line to the busbar) displayed positively. To do so, set address 1108
P,Q sign to reversed. If the setting is not reversed (default), the positive direction for the power etc.
corresponds to the "forward" direction for the protection functions. Section 4 provides a detailed list of the
values in question.
56
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
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