Basler BE1-25/79TR, Instruction Manual, Page: 36 / 78

BE1-25/79TR Functional Description
3-9
Slip Frequency Difference
For better control of closing angles, differences in the frequency of the bus and line can be limited when the
line input is an oncoming generator. The phase angle window must be set to greater than 180 degrees to
enable the slip frequency function only (the phase window is disabled). With the phase angle window set
to greater than 180 degrees, the phase angle inhibit will be disabled.
TRIPPING FUNCTION, POWER FAIL
There is one power fail (PF) function to trip the breaker in the event of a dead line, dead bus condition. This
function is enabled with a cutout switch mounted external to the relay through contact sensing input PF. The
power fail timer has a time delay of 1 to 99 seconds. This function is initiated when the PF contact sensing
input is enabled (closed), the breaker is closed, and both the line and bus are dead.
CONTROL FUNCTIONS
Counter Enable
One input, counter enable (CE), freezes all timers in their current state when the input is opened regardless
of the voltage monitor conditions. The front panel CE LED lights when the CE input is open. When the CE
input is closed, the timers resume timing. The timers also freeze when the CE contact sensing input is
closed, both bus and line are dead, and the breaker is opened.
Drive to Lockout
One input, drive to lockout (DTL), forces the relay into lockout regardless of voltage conditions and breaker
status.
Drive to Reset
The input, drive to reset (DTR), forces the relay into reset mode, the reset LED (RST) lights, and all target
LED's and memory outputs are turned off.
TIMING FUNCTIONS
Master Timer
The master timer allows the maximum window of time for a reclosing sequence and has a range of 1 to 999
seconds. When an abnormal condition occurs that requires reclose action (breaker opens and reclose timer
is enabled or HSR input is momentarily closed regardless of the state of the breaker), the master timer will
start counting down in seconds from its initial setting value along with all of the reclose timers (LT1, LT2,
RP1, RP2, and PAR). When the master timer coincides with a time out of one of the reclose timers, a close
pulse is initiated if all proper conditions exist for that reclose timer. The close pulse duration (CLOSE TD)
is programmable in the settings mode. The target LED for the successful reclose function lights and the
memory output is latched if the reclose function is LT1, LT2, RP1, or RP2. The master timer continues
counting down after reclose is attempted. Other reclose action may be taken as subsequent reclose time
delays time out if their requirements are met. After the master timer times out, the state of the breaker is
examined. If the breaker is closed the RST1 timer starts timing down. If the breaker stays closed for the
duration of the RST1 time delay, the relay goes to reset. If the breaker is open after the master timer times
out the relays goes to lockout except if a Live Line/Live Bus condition exists with the PAR input open
(disabled). In this case the RST2 timer will start timing down. If the Live Line/Live Bus with open PAR exists
for the duration of RST2, the relay goes to reset with the breaker open. In all other conditions with the