Loopdrive – User and installation manual
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3. Confirm that fault contact was activated.
4. Remove the connection between L+ or L- to earth.
5. Confirm that EARTH “active” (fast) indication on LDB turns into “memory” (slow).
6. Reset LDB into QUIESCENT mode.
h. Simulate ground wire open fault (optional)
1. Open ground wire on PRIMARY or SECONDARY output of LDB.
2. Confirm that EARTH indication on LDB appears.
3. Confirm that fault contact was activated.
4. Connect ground wire back to LDB.
5. Confirm that EARTH “active” (fast) indication on LDB turns into “memory” (slow).
6. Reset LDB into QUIESCENT mode.
i. Ch eck cables and connectors between LDB and Public Address / Voice Alarm system.
4. Fault finding – LDB
The effort and time spent of finding and fixing loudspeaker line faults with Loopdrive system is reduced to minimum.
Loopdrive is designed to locate and report the exact location of fault, even long time after its occurrence. You can
repeat fault finding procedures multiple times, any time you want, making sure that repair works will be efficient and
accurate.
Finding a loudspeaker line fault usually starts at the main system rack, where LDB units are located. Observe LDB
front panels and compare the indications to indication table in this manual.
NOTE:
Multiple faults can be shown on LDB at same time. SHORT, OPEN and EARTH fault may be detected and indicated simultaneously and
should be investigated individually
.
If fault indications on LDB are in “memory” state (slow blinking), simply push RESET button on LDB and after reboot
LDB will return to QUIESCENT mode.
Following information relates to situation where there is an active fault indicated. More details you’ll find in LDB
indications table (Table 1.) in chapter 1.
4.1. SHORT fault
LDB shows SHORT fault in following cases:
a. Short circuit on the loop, between FIM modules
In this case Short fault is located in the field, not directly at LDB connector. FIM modules are isolating faulty
section of the cable, so the loop stays open until the short circuit is removed. In this state reset of LDB will
clear the SHORT indication and LDB will detect loop open fault, indicating OPEN active.
b. Short circuit on the PRIMARY or SECONDARY port of LDB
In this case short circuit is located adjacent to LDB, therefore LDB detects the fault directly and any attempt
to reset LDB brings no result – LDB returns to SHORT active state.
