Siren from an alarm is massive, hence it is hard not to catch it going off, especially when it can continuously run for 10 minutes if the system is not deactivated. Deactivating the siren can be done either manually shutting the system or ringing the users up if they are being connected to mobile phones.
Some systems will make an effort to inform neighbours or relatives, while others may alert a remote service or call centre that are on 24/7 stand-by, so that trained security officer are sent to activated premises to attend to the situation. There are also incidences whereby the system is directly linked to nearby police departments, so that police officers are notified immediately.
False alarm or alarm going off without formal prompting should not happen, unless the system is poorly maintained. On average, false alarm should not take place more than 10 to 25% within a year. Nevertheless, on top of regular maintenance, there is still a need to keep an eye to prevent any abnormality.
Moreover, other power disruptions like blackouts or changes made to existing power circuits may also disturb the day-to-day function of an alarm system, setting the siren unexpectedly. It is easier for sensitive alarm system to experience false alarm during power failure because the system assumed an intruder cutting the supply on purpose.
Incorrect wiring which often resulted in short circuit, may also disrupt the alarm system. When it occurs, it is recommended to have a thorough check if any part of the system is damaged and correct re-wiring should take place.
It is naïve to think that a wireless system would have an easier time for false alarm. Indeed, non-wired alarm system may escape the fate of short circuit but they are not barred from other threats like interference. This is especially prominent if the alarm system is tied in with other wireless devices within the same surveillance system, such as remotes or door openers etc.
Natural disaster or sensors that are dirty will also contribute to a possible false alarm hence, to minimise the a false alarm, it is still best to have the system check and regularly maintained.