Basler Electric BE1-79M - Manual (Page 27)

9170100990 Rev N BE1-79M Functional Description 3-3
Figure 3-2. Contact Sensing Board Link Position
Recognition and response to closure of the sensing contacts is time dependent. All contact sensing inputs
must be present for a minimum of 6 milliseconds before recognition. For a reclosing sequence to begin,
the 52b contact closure must occur within 17.5 milliseconds after either RI or PI has dropped out. For a
longer output recognition (200 milliseconds), logic switch S23 provides a field selectable option (recogni-
tion dropout). If RI and PI are initiated simultaneously, PI takes priority. If a Pilot reclosing sequence is
initiated, IRB has no effect. DTL overrides all other inputs. The function of each set of sensing contacts is
described in Table 3-1.
Contact Interface
Contact interface circuits provide current limiting, filtering, and optoisolation. This interfacing translates the
state of the individual sensing contacts to logic levels. These logic levels are entered onto the data bus,
via buffers, for use by the microprocessor.
Logic Switch
Logic switch S23, is a field selectable, 16-position switch (0 through F), that enables any combination of
four functions. Refer to Table 2-2 for logic switch positions and functions enabled. The four functions are
Memory Save, Power-up to Reclose, Recognition Dropout, and Status LED Reset.
• Memory Save
•
- When power is lost, the relay initiates the memory circuit to store the exact point
at which the reclosing sequence was interrupted. Within 100 milliseconds of when power is reap-
plied, the relay will resume the reclosing sequence. Memory save function will occur ONLY if the
relay was in a reclosing sequence. It will not occur if the relay was in RESET, RELAY FAIL, or
LOCKOUT.
Power-up to Reclose
•
- When power is lost during a RESET condition, the relay initiates a first
programmed reclose after power is restored if the breaker is open (52b) and normal initiate (RI or
PI) is present.
Recognition Dropout
Figure 3-3
- This function replaces the standard recognition dropout time of 17.5 milli-
seconds. The relay initiates a reclosing sequence if a 52b occurs within 200 milliseconds of an RI
or PI. illustrates the recognition dropout timing relationship.
• Status LED Reset - After a reclosing sequence, the relay initiates STATUS LED reset (INST., 1, 2,
3, and PILOT) when the relay reaches RESET.