Here is a short summary of all the items that are used in a Intruder and Fire Alarm Systems. We have separate pages explaining each system in greater detail. Please feel free to browse them.
The control panel is the main workings of the system. The main control panel will normally be sited in a concealed place such as in a cupboard or roof space.
Most systems are operated using a user code or PIN that is inputted into a keypad that is normally located in a convenient place, for example by the front door. It is also possible to have a system that is set and unset using a ‘tag’ or key-fob that can be attached to a keyring.
These devices are the components of the system that will set off the alarm. Each detector that is fitted to the system is allocated its own ‘zone’. This allows each detector to be individually identified and the user to set part of the system only. For example it would be possible for the user to arm the downstairs detectors at night and leave the upstairs detectors off.
There are many types of movement detector available. The most common are PIR’s (Passive Infra- Reds). These are designed to be mounted in the corner of the room near to the ceiling. They detect changes in infrared energy that will be caused by a person moving in the room. When they activate a small red light on the front of the devices illuminates showing that a message is being sent to the control panel. If the system is armed the alarm will be set off. There are now also ‘Pet Friendly’ detectors available that can differentiate between humans and cats and dogs.
These sensors consist of a magnet and a contact that are usually encased in plastic. They are designed to be used where it is necessary to detect the opening of a window or door. These can be mounted on the surface or can be sunk into a frame so that they are flush to the frame.
These can be fitted on walls, windows or doors to detect physical vibrations, such as a door being kicked or a window being forced open.
Smoke & Carbon Monoxide Detectors
These detectors can be fitted to the alarm system so there is no need to worry about replacing batteries at regular intervals.
Personal Attack Button
The user can use this function to activate the alarm at anytime whether the alarm is set or not. In the event of a personal emergency it can be activated by operating a push button or at a remote keypad by pressing particular buttons. Wireless personal attack buttons are also available that you can carry on your person and will activate that alarm system from around you house and garden. An activated personal attack button that is connected to a monitored alarm system will be immediately policed providing the user with maximum personal protection.
These are the parts of the system that tell you – or someone else – that the alarm has been activated.
These provide a very loud audible warning inside the premises. It is designed to sound on activation until reset by a nominated operator.
External Bell Box
These are mounted on external walls but are well protected against both weather and unauthorised tampering or attack. They contain their own battery back up so that even if the box is removed from the wall it will continue to sound. The warning sounder will ring when the alarm is activated however, due to noise pollution legislation, they will not operate for more than 20 minutes at a time. The bell boxes can also have internally fitted strobe lights, giving a visual warning that the alarm is activated. The strobes will continue to flash even after the sounder has cut off.
A highly visible alarm bell box will provide a visual deterrent to potential intruders. It is possible to fit dummy boxes, possibly as secondary boxes, for example at the rear of the property.
These are a very useful addition to an alarm system. They are connected to the phone line and have the ability to dial up to four numbers upon alarm activation. This ensures that you or nominated keyholders are informed immediately of an alarm activation. They can be connected to an existing system or can be incorporated into a new system. Unlike a monitored system there are no additional annual fees for this function.
Monitored systems or remote signalled systems are connected to a specialist company called an Alarm Receiving Centre (ARC). These companies monitor the alarm signals 24 hours a day, 365 days a year. When a device is activated the alarm system sends a signal to the ARC. The ARC will pass the alarm call to the police but only when the alarm has become CONFIRMED. Monitored systems are often used to protect commercial and industrial premises but they are also installed in domestic premises where a greater level of protection is required and police response is wanted.
A fully monitored alarm system is more expensive to install and run than a ‘bells only’ system. The police require these systems to be covered by a maintenance contract and there are yearly monitoring fees to pay.
TYPES OF MONITORING
In order to have a system monitored it is necessary for the alarm system to transmit to a remote Alarm Receiving Centre (ARC). There are several different ways for the system to make this communication.
Digital signals are sent to the ARC via a phone line. The problem is that if the phone line is cut, the ARC will not receive the signals. This communication is usually acceptable for most domestic installations and is the most cost effective way of achieving a police response.
Monitored Telephone Line
This uses technology to constantly send encrypted signals to and from the alarm system. Unlike a digital communicator no dialling is involved, rather an electronic series of pulses is regularly transmitted via the phone line to the ARC. This makes the system high security as the phone line is constantly monitored. The ARC will be notified as soon as any signal is interrupted. This communication may require an extra phone line as it cannot use a phone line that transmits data i.e. fax, internet modem.
Radio Signals (GSM)
As the name suggests, radio signals are sent from the alarm to the ARC. This communication is high security as it does not rely on a phone line.
This is a combination of any of the other communication or signalling methods. This is usually in the form of a digital communicator with a radio or GSM back up. The first communication path is the phone line and should that fail the second radio path is reverted to. This makes the system high security.