
TWINFLEX
®
pro² Control Panel Engineering and Commissioning Manual
62
Fault Finding
Summary of Faults
Intermittent Zone Fault
1. Tighten the unused ‘zone screw terminals’ at the EOL device and check all connections
on the zone.
2. Too many sounders on a zone. Remove some or adjust sound levels down.
3. EOL resistor, capacitor or third party EOL device has been fitted. Remove and use the
correct DIL switch on the last device.
4. Interference from old or flickering fluorescent lights, low voltage transformers etc.
Ensure that the cable is screened and install a ferrite core on the zone cables. Ensure
that the detector is away from light fittings and from light, especially direct or reflected
sunlight.
5. Dirty or contaminated optical chambers. Replace with a new optical chamber or device.
6. Weak EOL signal. Replace the EOL device.
7. Faulty auto-calibration of EOL signal. Replace the EOL device.
8. More than one EOL. Temporarily switch off the EOL at the last device to see if the fault
has cleared. If the system stays clear then another device is set to EOL and this must
be found and switched off. It may be possible that more than 2 EOLs are switched on.
9. Earth fault. Ensure that all system earths are intact and not shorting to any other cables
or metal.
Permanent Zone Faults
1. More than one EOL switched ON. Temporarily switch off the EOL at the last device to
see if the fault has cleared. If the system stays clear then another device is set to EOL
and this must be found and switched off.
2. No EOL signal detected by panel. Switch the EOL on at the last device.
3. O/C or S/C on zone cables. Remove the zone cable from the control panel and check
with an electrical test meter (not a high voltage insulation test).
4. Tighten the unused ‘zone screw terminals’ at the EOL device.
5. Interference from old or flickering fluorescent lights, low voltage transformers etc.
Ensure that the cable is screened and install a ferrite core on the zone cables. Ensure
that the detector is away from light fittings and from light, especially direct or reflected
sunlight.
6. Dirty or contaminated optical chambers. Replace with a new optical chamber or device.
7. Output unit with no power or no link in fault input. I/O module with no or incorrect input
resistor or input EOL switch incorrectly set (switch number 6).
8. Faulty Zone at control panel (22-30 volts healthy, 1-21 volts faulty, 1 volt or less, zone
switched off or short circuit).
9. Weak EOL signal. Replace the EOL device.
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