Fault Finding - Fim; Short Loop; Short On T-Branch - 4EVAC Loopdrive 4E-LDB User And Installation Manual

Loopdrive – User and installation manual
5. Fault finding – FIM
Next step after identifying a fault on LDB is to investigate and fix the cabling in the field. Indication on FIM will help
you finding the exact location and type of the fault.
NOTE:
Multiple faults can be shown on FIM at the same time. In this case different fault indications will be superimposed, creating combined
indication. FIM can be reset only if all faults are removed and all indications are in "memory" state
If fault indications on FIM are in "memory" state (slow orange blinking), simply push RESET button on FIM (or send
REMOTE FIM RESET command from LDB) and after reboot FIM will return to QUIESCENT mode.
Following information relates to situation where there is an active fault indicated. More details you'll find in FIM
indications table (Table 4. and Table 3.) in chapter 1.

5.1. Short loop

If loop is shorted on either of the sections connected directly to FIM, the LED indicator on the faulty section side will
blink orange fast. FIM is isolating the faulty section with open relay. T-Branch is still operational and fed with audio
from the healthy side of the loop.
Picture 17. Short on side A
What to do?
Remove the short-circuit from the loop section. When the problem is fixed, the fast blinking indication on FIM will
turn slow. Now you can reset FIM to QUIESCENT mode, where both A and B relays are closed. To reset FIM:
a) push RESET button on the FIM module
or
b) send REMOTE FIM RESET command by pressing RESET button on LDB for 10 seconds or via Sniffer
application.

5.2. Short on T-Branch

If T-Branch is shorted, both A and B indicators will blink fast orange alternately. Both relays of the FIM are open,
creating an interruption in the loop. T-Branch is isolated from the loop.
What to do?
Remove the short-circuit from the T-Branch. When the problem is fixed, the fast blinking indication on FIM will turn
slow. Now you can reset FIM to QUIESCENT mode, where both A and B relays are closed. To reset FIM:
Picture 19. Short on T-Branch
Picture 18. Short on side B.
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