Toshiba GR200 Series Instruction Manual page 110

6F2S1931 (0.20)
Fail safe (FS)
A trip signal is issued when respective protection functions are activated by faults. High
reliability is required for the issue of trip signals. Hence, a fail-safe (FS) function can be
introduced to ensure that the protection functions issue the trip signals securely; such that the
trip signal can be issued when the trip conditions are established.
The FS function includes the following elements; an under-voltage element for phase-to-
earth faults (UVFS), under-voltage element for phase-to-phase faults (UVSFS), under-voltage
change detection element (UVDFS). These elements operate in all six busbar protection zones.
Each element has a scheme switch, and the scheme switch enables/disables the element
independently. That is, zone A to zone F and common settings are provided in the setting list.
Note that the user should enter the value of the VT secondary circuit voltage when setting.
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Note: The implementation of particular features is dependent upon the selection of
hardware and the configuration of functions. Several IED models do not support certain
features. To determine whether a particular feature has been implemented within an IED,
identify the IED ordering number; and check the order number for the "G&T position" whilst
referring to the comparison table below. For more information, see Appendix: Ordering.
Table 2.3-1 Comparative table in respective ordering numbers
Ordering No. at "G&T"
Sec. Feature
30 31 32 33 34 Note
– FS main features  NA   NA   
: Applicable NA: Not applicable

Centralized GRB200
(Soft: 030, 031, 032, 033, 034)
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