Vigilant MX1 - Nuisance Alarms

Vigilant MX1 Operator Manual Document: LT0344
Page 1-18 8 August 2017 Issue 2.4
Nuisance alarms (also called false alarms or unwanted alarms) are alarm
conditions caused by events other than a fire. These can be generally
categorised according to two causes:
 The detector has correctly sensed the phenomena it is designed to
detect, but the reason for the phenomena being present is not a fire.
Examples are: a heat detector being triggered by very hot air from an
oven, hot outside air entering an air-conditioned foyer, smoke from an
outside fire triggering a smoke detector in the building, or welding
setting off a flame detector.
 The detector has sensed a phenomenon different to what it is
designed to detect, but one that causes similar effects to the detector.
For example: steam or insects setting off a photoelectric detector,
dust from building works, a nail being driven through detector cabling,
or radio interference affecting a detector.
The actions to reduce the occurrence of both causes are generally the
same and involve:
 Removing the unwanted effect that is causing the detector to
operate.
 Repositioning the detector so it is not influenced by the effect.
 Changing the settings of the detector so it is more resilient to the
effect.
 Changing the detector type to one that is not sensitive to the effect,
but is still suitable for the environment and the risk.
Some precautions building owners/occupiers can take to reduce the
possibility of nuisance alarms include:
 If structural repairs or maintenance are to be performed in the
building, ensure that any work that generates dust or smoke is only
carried out after the relevant zones have been disabled. Smoke
detectors should be fitted with temporary covers to prevent dirt from
accumulating. Once the work is complete, remove the covers, reset
any alarms detected while the zone was disabled, and then enable
the zone.
 Ensure that kitchens, bathrooms, and shower rooms are fitted with
exhaust fans, and that if provided with closing doors there is pressure
relief to allow effective extraction when the doors are closed.
Nuisance Alarms