Siemens siprotec 7SA522 User Manual page 101

Special Cases
7SA522 Manual
C53000-G1176-C119-2
Figure 5-1 Device Configuration dialogue box in DIGSI
Before closing the dialogue box, transfer the modified functional setting to the relay by
clicking on the item ',*6, → 'HYLFH. The data is stored in the relay in a non-volatile
memory buffer.
The configured functional scope can be viewed at the front of the relay itself, but can-
not be modified there. The settings associated with the functional scope can be found
in the 0$,1 0(18 under → 6HWWLQJV → 'HYLFH &RQILJ.
Most settings are self-explanatory. The special cases are described below.
If the setting group change-over function is to be used, the setting in address 
*US &KJH 237,21 must be set to (QDEOHG. In this case, it is possible to apply up to
four different groups of settings for the function parameters (refer also to Sub-section
6.1.2). During normal operation, a convenient and fast switch-over between these set-
ting groups is possible. The setting 'LVDEOHG implies that only one function parame-
ter setting group can be applied and used.
The tripping characteristic type can be selected for the distance protection, dependent
on the device version. In setting address  the selection for the phase–phase
measuring systems 3KDVH 'LVWDQFH is done and in address  the selection for
the phase–earth measuring systems (DUWK 'LVWDQFH is done. A selection between
a polygonal tripping characteristic 4XDGULODWHUDO and circular MHO characteristic
0+2 is available. In Sub-sections 6.2.3 and 6.2.4 the characteristics and measuring
techniques are described in detail. The setting in these two addresses may be differ-
ent. If the device is to be applied for only phase–earth loops or only phase–phase
loops, then the unused function is set to 'LVDEOHG.
If the distance protection is to be supplemented with a teleprotection system, the de-
sired scheme can be selected in address  7HOHSURW 'LVW. A selection be-
tween the permissive underreach transfer scheme 3877, the permissive overreach
transfer scheme 3277, the 81%/2&.,1* scheme, and a %/2&.,1* scheme are avail-
able. These schemes are described in detail in Sub-section 6.4.1. If a teleprotection
supplement is not required for the distance protection, the setting must be 'LVDEOHG.
The tripping characteristic of the time delayed overcurrent protection can be set in ad-
dress  %DFNXS RYHUFXUUHQW %DFN8S 2& . In addition to the definite time
Configuration
®
4 — example
5-3