For this reason all modern alarm systems have a battery backup designed to power the system for 10 24 hours depending on the complexity of the system and the condition of the battery.
Burglar alarm sounds when power cut.
This means the back up battery which is meant to keep the alarm running is unable to keep the alarm system running therefore setting the alarm off.
Of course the alarm can t tell the reason for the mains supply being interupted hence why it sounds when there is an unintentional power cut.
And i agree it s an absolute nightmare i ve often considered my ladders and a lump hammer when it happens locally.
When mains power is cut to an alarm most alarms sound powered by their own internal rechargeable batteries.
It s also quite possible that the 20 minute limit is disabled with a power cut as well.
No is the only answer to this question.
When all power is cut including power to alarm systems the number is even higher.
To avoid any faults with your burglar alarm it needs to be regularly serviced.
Alarms also commonly go off when the power is interrupted presumably because it thinks that a burglar has cut the power to try and break in.
98 of the time an alarm rings during a power cut is because this battery is dead.
All professionally installed and maintained alarm systems must have a fully operational battery back up system that should keep the system operational for at least 12 hours and it should be checked by your maintainer each year.
Therefore when the mains is removed the main control panel battery can t keep the system running so the external sounder starts ringing to inform you there s a problem.
The backup battery maintains power to the alarm panel sensors and sounder in the event of a power cut or when an intruder cuts the mains power to the panel.
This is a security feature to prevent burgulars simply cutting power to an alarm to stop it.
So what can happen if you do not change or renew the battery.
In less expensive systems nickel metal hydride nimh aa cells may be used.
An alarm panel is usually provided with backup power by a 12 volt lead acid battery.
Well after 5 years the battery can deteriorate and could eventually damage the control panel as this unit also operates as a battery.