ABB REL-300 Instruction Leaflet page 81

I.L. 40-385.1B
(front view). All the trip contact outputs are connect-
ed to the right-side FT-14 switch (front view). Switch-
es 13 and 14 on FT-14 may be used for disabling the
Breaker Failure Initiation/Reclosing Initiation (BFI/
RI) control logic. (See also external connections,
Block Diagram, Appendix J.)
The INCOM or RS232 PONI (Product Operated Net-
work Interface) communication box is mounted
through the Backplate of the outer chassis and con-
nected to the Backplane module, and remote set-
tings (see 4.7).
4.4 MDAR FRONT PANEL DISPLAY
The front panel display consists of a vacuum fluores-
cent display, seven LED indicators, seven pushbut-
ton switches, and five test points (as shown in Figure
1-1).
4.4.1 Vacuum Fluorescent Display
The vacuum fluorescent display (blue color) con-
tains four alphanumeric characters for both the func-
tion field and the value field. All the letters or num-
bers are fourteen segment form (7.88mm x 13mm in
size).
4.4.2 LED Indicators
There are seven LED indicators on the front panel
display:
• 1 "relay-in-service" indicator
• 1 "value accepted" indicator
• 5 display-select indicators
When the "Relay-in-Service" LED illuminates, the
MDAR Relay is in service, there is dc power to the
relay and the relay has passed the self-check and
self-test. The LED is turned "OFF" if the Relay-in-
service relay has at least one of the internal failures
shown in the "Test" mode, and the trip will be
blocked.
The "Value Accepted" LED flashes only once, to in-
dicate that a value has been entered successfully.
The five indicators used for the display selection are:
• Settings
• Volts/Amps/Angle
• Last Fault
• Previous Fault
• Test
4-2
One of these indicators is always illuminated, indi-
cating the mode selected. The display will be
blocked momentarily every minute for the purpose of
self-check; this will not affect the relay protection
function.
4.4.3 Pushbutton Switches
The front panel contains seven pushbutton switches:
• Display Select
• Reset Targets
• Function Raise
• Function Lower
• Value Raise
• Value Lower
• Enter (recessed for security purposes)
The "Display Select" pushbutton is used to select
one of the five display modes, which is indicated
when the proper LED illuminates. When a fault is de-
tected, the "Last Fault" flashes once per second. If
two faults are recorded, the "Last Fault" flashes
twice per second, and the prior fault will be moved
from "Last Fault" to "Previous Fault". The new fault
data will be stored in the "Last Fault" register. By de-
pressing the "Reset Targets" pushbutton, the flash-
ing LED indicators are cleared, and the LED will re-
vert back to the Metering mode. The information in
the "Previous Fault" and "Last Fault" will not be reset
from the front panel pushbutton switch, but will be re-
set from External Reset (TBS/5 and TBS/6) and the
remote reset through the Communication Interface.
The "Function Raise" and "Function Lower" pushbut-
tons are used to scroll through the information for the
selected display mode. The "Value Raise" and "Val-
ue Lower" pushbuttons are used to scroll through the
different values available for each of the five func-
tions. The "Enter" pushbutton is used to enter (in
memory) a new value for settings.
4.4.4 Test Points
Five test points are provided to check the dc power
supply. Refer to these test points on the front panel
display:
• -24V
• + 5V
• -12V
• +12V
• Common
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