KK-641.002 Rev.No:1 01.08.12 ML-121X User Manual Page | 11
6.3 Internal Indicators
Internal Indicators on SLCU (Single Loop Card Unit) (Annex-B, Figure-16);
SEND LED: While sending communication signal to the devices in the loop, it blinks as RED.
RECEIVE LED: While receiving responses from the devices in the loop, it blinks as
GREEN.
7- PANEL FUSES
Fuses on the panel;
SLCU Fuse (FS1) is a self-resetting fuse and becomes active on 0.5А current overload at the
loop output line. The General fault LED illuminates and on LCD screen ‘Loop open or Short
circuit’ comment is seen. Panel’s loop output becomes unusable. In each single loop card this
fuse is present.
Sounder 1 Self-resetting fuse (FSO3)
Self-resetting and becomes active on 0.5А current overload. Sounder fault Led illuminates,
and on LCD screen ‘Sounder 1 open circuit’ message is seen. Panel’s sounder-1 output
becomes unusable.
Sounder 2 Self-resetting fuse (FSO4)
Self-resetting and becomes active on 0.5А current overload. Sounder fault Led illuminates,
and on LCD screen ‘Sounder 2 open circuit’ message is seen. Panel’s sounder-2 output
becomes unusable.
Sounder 3 Self-resetting fuse (FSO5)
Self-resetting and become active on 0.5А current overload. Sounder fault Led illuminates, and
on LCD screen ‘Sounder 3 open circuit’ message is seen. Panel’s sounder-3 output becomes
unusable.
Sounder 4 Self-resetting fuse (FSO1)
Self-resetting and becomes active on 0.5А current overload. Sounder fault Led illuminates,
and on LCD screen ‘Sounder 4 open circuit’ message is seen. Panel’s sounder-4 output
becomes unusable.
24 V DC Self-resetting Fuse (FSO2)
Self-resetting and becomes active on 0.5А current overload or wrong connection into the
output. The General fault LED illuminates and ‘24 V Fault’ comment is seen on LCD screen.
24 V DC output becomes unusable.
Internal Indicators on MLY-0502 Power Supply;
28 V input fuse (F1)
3 A self-resetting fuse becomes active in case the power supply becomes faulty.
Battery fuse (F2)
1.1 A self-resetting fuse becomes active upon any fault or short circuit at battery inputs.
28 V output fuse (F3)
3A self-resetting fuse becomes active upon short circuit in 28 V output of power supply. In this
case, the outputs of power supply become de-energized.
Note: the placement of the fuses is shown in Annex-B.