OUTPUTS
Defined by the style number, the output relays may be provided for each of the following functions: timed
undervoltage, timed overvoltage, instantaneous undervoltage, and instantaneous overvoltage. Auxiliary
output relays may be provided for each of these functions as well. Once energized, output relays will
remain energized until the adverse condition stops.
PUSH-TO-ENERGIZE OUTPUT PUSHBUTTONS
Small pushbutton switches may be provided as an option to allow testing the primary output contacts and
(if present) the auxiliary output contacts. To prevent accidental operation, the pushbuttons are recessed
behind the front panel and are depressed by inserting a thin, non-conducting rod through an access hole
in the front panel.
POWER SUPPLY STATUS OUTPUT
The power supply status relay has a set of normally closed contacts and energizes when operating power
is applied to the relay. If relay operating power is lost or either side of the power supply output (+12 Vdc
or –12 Vdc) fails, the power supply status relay de-energizes and opens the power supply status output
contacts.
POWER SUPPLY
Operating power for the relay circuitry is supplied by a wide range, electrically isolated, low-burden power
supply. Power supply operating power is not polarity sensitive. The front panel power LED and power
supply status output indicate when the power supply is operating. Power supply specifications are listed in
Table 1-1.
TARGET INDICATORS
Target indicators are optional components selected when a relay is ordered. The electronically latched
and reset targets consist of red LED indicators located on the relay front panel. A latched target is reset
by operating the target reset switch on the front panel. If relay operating power is lost, any illuminated
(latched) targets are extinguished. When relay operating power is restored, the previously latched targets
are restored to their latched state.
A relay can be equipped with either internally o
perated targets or current operated targets.
Internally Operated Targets
The relay trip outputs are directly applied to drive the app
ropriate target indicator. Each indicator is
illuminated regardless of the current level in the trip circuit.
Current Operated Targets
A current operated target is triggered by clo
sure of the corresponding output contact and
the presence of
at least 200 milliamperes of current flowing in the trip circuit.
NOTE
Prior to September 2007, BE1-27/59 target indicators consisted of magnetically
latched, disc indicators. These mechanically latched target indicators have been
replaced by the electronically latched LED targets in use today.
3-6 BE1-27/59 Functional Description 9170600990 Rev H
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