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Amended: Jan 2014
“Short Circuit” start or end of a loop.
There is a short at the start or end of the mentioned loop. The fault can only be on the panel. The
first/last device or the wiring in between the panel and the device. This prevents the loop driver from
functioning and must be fixed in order to auto-learn the panel. Common causes would be:-
Either the first or last device is wired incorrectly.
The loop connections into the panel are wrong.
Something is shorting on the PCB.
No device between the last Spur Isolator and the panel
If the initial loop test didn't show a short across the loop power down the panel and remove the loop
driver.
Measure the resistance across the loop using the appropriate terminals, If this is still in the Mohm
region change the loop driver card. If this is short circuit recheck the loop by disconnecting the loop
and measuring.
If this is Mohms change the motherboard.
“Short circuit middle”
Device wired incorrectly. See wiring diagram.
Device is drawing too much current. A faulty device may draw too much current and be detected as a
short.
Replace the device.
“Fault at address”
There are several possible causes of faults at individual addresses, the panel may show more
information (e.g. which channel for 3 channel IO) or may show analogue value for the fault:-
Device is missing, unlikely after an auto-learn as a missing device wouldn't have addressed. Incorrect
earthing may cause this. This fault would have an analogue value of 0.
A repeater, sounder control unit have their own power supply if the PSU is not on and there is no
battery, the device will show a fault, analogue value 0.
Detector low analogue value fault. If the detector shows analogue value of 1 the detector may need
replacing or cleaning.
End of line resistors not correct. IO units, ZMUs etc. have end of line resistors. If they are not wired
correctly the panel will show a fault at this address but will give specific information (ZMU detector
zone etc.) about the fault.
