Basler Electric BE1-64F - Manual (Page 16)

Block Input
Applying voltage to terminals A10 (line) and A11 (neutral) disables the relay alarm and trip functions and
removes the dc voltage impressed across the protected circuit and ground. The block input accepts
voltage in the range of 90 to 132 Vac. Note that the block input shares terminal A11 (neutral) with the
power input.
Field (F–) and Rotor Ground Interface
This interface supplies approximately 55 Vdc to the protected circuit through terminals A1 (F–) and A3
(GND (CORE)). This interface voltage is removed when the block input is energized.
Current Detector and Reference
If a ground fault occurs between the protected circuit and ground, fault current flows from terminal A1 (F–)
to A3 (GND (CORE)). This fault current is measured and scaled by the current detector. A compensated
reference is also developed for comparison with the scaled current detector output level. The reference
and current detector levels are supplied to the trip comparator and alarm comparator circuits for use in the
determination of alarm and trip conditions.
Alarm Comparator
The alarm comparator compares the output level of the current detector with a scaled version of the
reference output. An alarm condition is determined if the current detector output level exceeds the scaled
reference output level for approximately 0.75 seconds. When an alarm condition is determined, the alarm
comparator sends a signal to the pre-alarm output contact circuit. The pre-alarm output contact closes
and the front panel Alarm LED lights for as long as the alarm condition exists.
Pre-Alarm Output Contact
This circuit is controlled by the alarm comparator output and closes the output contact for the duration of
an alarm condition (unless the block input is energized). Connections to the pre-alarm output contact are
made at terminals A4 and A5 (PRE-ALARM).
Trip Comparator
The output levels of the current detector and reference are compared by the trip comparator. A trip
condition is determined when the current detector output level exceeds the reference output level for
approximately 0.75 seconds. During a trip condition, the trip comparator sends a signal to the ground trip
output contact circuit, the ground trip output contact closes, the front panel Output Trip and Output Alarm
LEDs light, and the Target Trip LED latches on. If the trip condition is cleared, the Output Trip and Alarm
LEDs turn off, but the Target Trip LED remains on until the Target Reset pushbutton is pressed.
Gnd Trip Output Contact
This circuit is controlled by the trip comparator output and closes the output contact for the duration of a
trip condition (unless the block input is energized). Connections to the gnd trip output contact are made at
terminals A6 and A7 (GND TRIP).
Loss of AC Power Alarm Output Contact
This output contact is open during normal operation and closes when relay operating power is lost.
Contact connections are made at terminals A8 and A9 (PWR FAIL).
Target
The target circuit latches the front panel Target Trip LED on when a trip occurs. The target circuit remains
latched even when relay operating power is lost. Pressing the front panel Target Reset pushbutton resets
the target and Target Trip LED (unless an active trip condition is present).
Reset
The reset circuit responds to the front panel Target Reset pushbutton and returns the target to an
untripped condition (unless an active trip condition is present).
3-2 BE1-64F Functional Description 9367200990 Rev B