GE L90 Instruction Manual page 115

5 SETTINGS
b) LED TEST
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PATH: SETTINGS PRODUCT SETUP
# LED TEST
#
MESSAGE
When enabled, the LED Test can be initiated from any digital input or user-programmable condition such as user-program-
mable pushbutton. The control operand is configured under the
including the LEDs of the optional user-programmable pushbuttons.
The test consists of three stages.
Stage 1: All 62 LEDs on the relay are illuminated. This is a quick test to verify if any of the LEDs is "burned". This stage
lasts as long as the control input is on, up to a maximum of 1 minute. After 1 minute, the test will end.
Stage 2: All the LEDs are turned off, and then one LED at a time turns on for 1 second, then back off. The test routine
starts at the top left panel, moving from the top to bottom of each LED column. This test checks for hardware failures
that lead to more than one LED being turned on from a single logic point. This stage can be interrupted at any time.
Stage 3: All the LEDs are turned on. One LED at a time turns off for 1 second, then back on. The test routine starts at
the top left panel moving from top to bottom of each column of the LEDs. This test checks for hardware failures that
lead to more than one LED being turned off from a single logic point. This stage can be interrupted at any time.
When testing is in progress, the LEDs are controlled by the test sequence, rather than the protection, control, and monitor-
ing features. However, the LED control mechanism accepts all the changes to LED states generated by the relay and
stores the actual LED states (On or Off) in memory. When the test completes, the LEDs reflect the actual state resulting
from relay response during testing. The Reset pushbutton will not clear any targets when the LED Test is in progress.
A dedicated FlexLogic™ operand,
tiated, the LED Test Initiated event is stored in the Event Recorder.
The entire test procedure is user-controlled. In particular, Stage 1 can last as long as necessary, and Stages 2 and 3 can be
interrupted. The test responds to the position and rising edges of the control input defined by the
ting. The control pulses must last at least 250 ms to take effect. The following diagram explains how the test is executed.
GE Multilin
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USER-PROGRAMMABLE LEDS
LED TEST FUNCTION:
Disabled
LED TEST CONTROL:
Off
, is set for the duration of the test. When the test sequence is ini-
LED TEST IN PROGRESS
L90 Line Differential Relay
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LED TEST
Range: Disabled, Enabled.
Range: FlexLogic™ operand
setting. The test covers all LEDs,
LED TEST CONTROL
5.2 PRODUCT SETUP
5
set-
LED TEST CONTROL
5-25