Setting Notes - Siemens Siprotec 7VK61 Manual

2.7.1.6 Setting Notes

General
The sensitivity of the measured value monitoring can be changed. Experiential values set ex works are ade-
quate in most cases. If particularly high operational asymmetries of the currents and/or voltages are expected,
or if one or more monitoring functions pick up sporadically during normal operation, the sensitivity setting(s)
should be reduced.
The measurement supervision can be switched ON or OFF in address 2901 MEASURE. SUPERV.
Current balance supervision
Address 2902 BALANCE U-LIMIT determines the limit voltage (phase-to-phase), above which the voltage
symmetry monitoring is effective. Address 2903 BAL. FACTOR U is the associated balance factor, i.e. the
gradient of the balance characteristic. The indication „Fail U balance" (no. 167) can be delayed at address
2908 T BAL. U LIMIT. These settings can only be changed using DIGSI at Additional Settings.
Address 2904 BALANCE I LIMIT determines the limit current above which the current symmetry monitoring
is effective. Address 2905 BAL. FACTOR I is the associated balance factor, i.e. the gradient of the balance
characteristic. The indication „Fail I balance" (no. 163) can be delayed at address 2909 T BAL. I
LIMIT. These settings can only be changed using DIGSI at Additional Settings.
Summated current supervision
Address 2906 ΣI THRESHOLD determines the limit current above which the current sum monitoring is activat-
ed (absolute portion, only relative to I
vating the current sum monitoring is set at address 2907 ΣI FACTOR. These settings can only be changed
using DIGSI at Additional Settings.
Note
Current sum monitoring can operate properly only when the residual current of the protected line is fed to the
fourth current input (I
Asymmetrical measuring voltage failure "Fuse Failure Monitor"
The settings of the „Fuse Failure Monitor" for asymmetrical measured voltage failure must be selected so that
on the one hand reliable pickup of the monitoring is ensured in the case of loss of a phase voltage (address
2911 FFM U>(min)), while on the other hand a pickup due to earth faults in an earthed system is avoided. In
accordance with this requirement, address 2912 FFM I< (max) must be set sufficiently sensitive (below the
smallest fault current due to earth faults). These settings can only be changed using DIGSI at Additional Set-
tings.
In address 2910 FUSE FAIL MON., the „Fuse Failure Monitor", e.g. during asymmetrical testing, can be
switched OFF.
Measured voltage failure monitoring
In address 2915 V-Supervision, the measured voltage supervision can be switched to w/ CURR.SUP, w/
I> & CBaux or OFF. Address 2916 T V-Supervision is used to set the waiting time of the voltage failure
supervision. This setting can only be changed in DIGSI at Display Additional Settings.
SIPROTEC, 7VK61, Manual
C53000-G1176-C159-3, Release date 05.2009
). The relative portion (relative to the maximum phase current) for acti-
N
) of the relay.
4
Functions
2.7 Monitoring Function
143