Address 2904 BALANCE I LIMIT determines the limit current above which the current symmetry monitor is
effective. Address 2905 BAL. FACTOR I is the associated symmetry factor; that is, the slope of the
symmetry characteristic curve. The indication
Fail I balance
(no. 163) can be delayed at address 2909 T
BAL. I LIMIT. These settings can only be changed via DIGSI at Display Additional Settings.
Summation Monitoring
Address 2906 Σ I THRESHOLD determines the limit current, above which the current sum monitor is acti-
vated (absolute portion, only relative to Ι
Nom
). The relative portion (relative to the maximum conductor
current) for activating the current sum monitor is set at address 2907 Σ I FACTOR. These settings can only
be changed via DIGSI at Display Additional Settings.
NOTE
Current sum monitoring can operate properly only when the ground current of the protected line is fed to
the fourth current measuring input (Ι
4
) of the device. The Ι
4
transformer must have been configured as In
prot. line via parameter I4 transformer (220), see Appendix C Connection Examples.
Wire Break Monitoring
Wire break monitoring is enabled or disabled via parameter 2931 BROKEN WIRE. Only when set to ON, is the
differential protection function blocked. When set to Alarm only, a broken wire is signaled but the protec-
tion functions are not blocked.
Asymmetrical Measuring Voltage Failure „Fuse-Failure-Monitor“
The settings for the “Fuse-Failure-Monitor” for non-symmetrical measuring voltage failure (address 2911 FFM
V>(min)) are to be selected so that reliable activation occurs if a phase voltage fails, but not such that false
activation occurs during ground faults in a grounded network. Address 2912 FFM I< (max) must be set as
sensitive as required (with ground faults, below the smallest fault current). These settings can only be
changed via DIGSI at Display Additional Settings.
In address 2910 FUSE FAIL MON., the “Fuse-Failure-Monitor” can be switched OFF e.g. during asymmetrical
testing.
3-Phase Measuring Voltage Failure „Fuse-Failure-Monitor“
The minimum voltage below which a 3-phase measured voltage failure is detected is set in address 2913 FFM
V<max (3ph) unless a current step takes place simultaneously which exceeds the limit according to address
2914 FFM Idiff (3ph). These settings can only be changed via DIGSI at Display Additional Settings.
In address 2910 FUSE FAIL MON., the “Fuse-Failure-Monitor” can be switched OFF e.g. during asymmetrical
testing.
Measured Voltage Failure Monitoring
In address 2915 V-Supervision, the measured voltage failure monitoring can be switched to w/
CURR.SUP, w/ I> & 52a or OFF. Address 2916 T V-Supervision is used to set the waiting time of the
voltage failure monitoring. This setting can only be changed using DIGSI at Display Additional Settings.
Settings
Addresses which have an appended “A” can only be changed with DIGSI, under “Additional Settings”.
The table indicates region-specific default settings. Column C (configuration) indicates the corresponding
secondary nominal current of the current transformer.
Addr.
Parameter C Setting Options Default Setting Comments
2901 MEASURE. SUPERV ON
OFF
ON Measurement Supervision
2902A BALANCE V-LIMIT 10 .. 100 V 50 V Voltage Threshold for
Balance Monitoring
2.14.1.6
Functions
2.14 Monitoring Functions
160 SIPROTEC 4, 7SD80, Manual
E50417-G1100-C474-A2, Edition 02.2018