Siemens SIPROTEC 7SS523 V3.2 Manual page 142

Functions
5.3.6 Setting Notes
BF BI MODE
BF OP MODE
126
With the parameter T-BF CB fault (XX24/CU), the delay time of the breaker failure
protection can be reduced.
A TRIP command from the bay unit issues at the same time a transfer trip command
to trip the remote end (Figure 5-22, page 120).
The parameter BF BI MODE (XX14/CU) is used to select the supervision mode for
initiation of the breaker failure protection.
With setting 1-ch w/o sup, the breaker failure protection will be initiated only by the
feeder-selective binary input, without time supervision.
With setting 1-ch w sup, the breaker failure protection will be initiated only by the
feeder-selective binary input, with time supervision.
With setting 2-ch w/o sup, the breaker failure protection will be initiated after eval-
uation of an additional binary input ("CBF release"), without time supervision.
With setting 2-ch w sup, the breaker failure protection will be initiated after evalua-
tion of an additional binary input ("CBF release"), with time supervision.
For testing purposes, Siemens recommends to set this parameter to 1-ch w/o sup
or 2-ch w/o sup.
Note
The operating modes "... without supervision" are recommended for test purposes
only.
The parameter BF OP MODE (XX15/CU) is used to select the operating mode for the
breaker failure protection in the bay unit. The parameter setting depends on the pro-
tection concept in use.
With setting non existent the breaker failure protection will be deactivated.
With setting I>query the I> query mode is activated.
With setting trip rep/I>quer the TRIP repetition with subsequent I> query mode
is activated.
With setting BZ unbalance the unbalancing mode is activated.
With setting trip rep/unbal the TRIP repetition with subsequent unbalancing
mode is activated.
With setting external the breaker failure protection will be provided by an external
device.
7SS52 V4 Manual
C53000-G1176-C182-1