2-2
BE1-50/51B-235/-236 Controls and Indicators
9252000898 Rev —
Table 2-1. Front Panel Controls and Indicators
Locator Description
A
Instantaneous Overcurrent Manual Trip Jacks.
These jacks are used to manually trip a
breaker controlled by the 50-A trip output contacts. This is achieved by plugging a jumper
wire, terminated with two standard 0.08 inch diameter phone-tip plugs, into the two jacks.
These jacks do not activate the 50-B trip output contacts.
B
Instantaneous Overcurrent A Pickup Selector Switches.
These two rotary switches select
the instantaneous overcurrent A (50-A) pickup current setting in amperes (UNITS and
TENTHS on the BE1-50/51B-235, COARSE and FINE on the BE1-50/51B-236). Adjusting
these selector switches while the relay is in service may cause the relay to trip.
NOTE
When testing time overcurrent functions, instantaneous pickup settings of 00
will affect the calibration of the time functions. Time pickup settings of 00 also
affect instantaneous functions.
C
Target Indicators.
Red target indicators latch when the corresponding set of trip contacts
closes and sufficient trip circuit current is detected. (The level of current that will trip each
target indicator is jumper-selectable. See
Circuit Board Controls
for more information.) The
Time target indicates the flow of current in the time overcurrent (51) trip circuit. The Inst
target indicates the flow of current in the instantaneous overcurrent A (50-A) trip circuit. No
target is provided for the instantaneous overcurrent B (50-B) trip circuit. Both target
indicators are reset by pressing the target reset button (locator I).
D
Time Overcurrent Pickup Selector Switches.
These two rotary switches select the time
overcurrent pickup current setting in amperes (UNITS and TENTHS on the BE1-50/51B-
235, COARSE and FINE on the BE1-50/51B-236). Adjusting these selector switches while
the relay is in service may cause the relay to trip.
E
Curve Selector Switch.
This ten position rotary switch selects one of nine inverse timing
characteristics or one fixed time function. Refer to Appendix A,
Characteristic Curves
for
details about the timing characteristics of the BE1-50/51B-235 and BE1-50/51B-236.
F
Time Overcurrent Time Dial Selector Switches.
These two rotary switches select the
desired curve of the timing characteristic selected by the Curve Selector Switch (locator E).
When a fixed time characteristic is used (Curve Selector Switch setting of F), the setting of
these switches corresponds to a time delay of 0.0 to 9.9 seconds.
G
Time Overcurrent Manual Trip Jacks.
These jacks are used to manually trip a breaker
controlled by the 51 trip output contacts. This is achieved by plugging a jumper wire,
terminated with two standard 0.08 inch diameter phone-tip plugs, into the two jacks.
H
Active/Pickup Indicator.
This bicolor LED indicates the level of current sensed by the relay.
The LED is red when the sensed current exceeds the time overcurrent pickup setting. The
LED color changes from red to green when the sensed current decreases below 95% of the
time overcurrent pickup setting. A green LED indicates that the relay is active but not picked
up.
I
Target Reset Button.
This button is pressed to reset the two, gravity-latched target
indicators (locator C).
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