Silencing False Alarms
Warnock, William J., Security Management
THE PROBLEMS ASSOCIATED WITH false alarms have received considerable attention lately--in the media, in legislation at the state and local levels, and by law enforcement officials who must respond to the alarms. Just what constitutes a false or nuisance alarm, and how can they be avoided?
A false alarm is anything that affects the electronics of the system or the transmission lines. A nuisance alarm is any sensor response to unintentional stimuli.
False and nuisance alarms can be controlled. If your company wants to install an alarm system, a number of factors need to be considered. For starters, companies must follow a few common sense basics. Equipment must be reliable, affordable, available, maintainable, and expandable.
Consider the hourly maintenance charges for service when the system is out of warranty and whether you can afford the repairs. Determine whether the system can be retrofitted if newer technology comes along.
You need to have confidence in your system and be well trained in its functions and operation. Your training should include a list of do's and don'ts, which can go a long way toward eliminating false and nuisance alarms.
In addition, ensuring that a site has been carefully examined and prepared is crucial to the successful operation of an alarm system. In installing alarm systems--whether industrial, commercial, or residential--half the technical battle is won with a thorough site survey. A site survey includes looking at environmental factors as well as testing for the effects of inductive, conductive, and radiative interference.
Site preparation is far more complex and comprehensive than many clients realize. A site survey involves asking a lot of questions. It also means the people who are responsible for the system's design must work closely with the installers before and during the installation.
As a client, you should ask yourself many of the same questions the installer needs to know. For example, in what type of environment will the alarm system be placed and expected to operate efficiently?
What is the condition of the building's electrical system? This includes the building's transformers and switchboards; bonding and grounding networks; circuit-breaker panels, switches, and receptacles; and all of the wiring in between.
Electrical noise from one part of the building can travel through the building's wiring and interfere with or damage electronic equipment. Loose connections, in addition to causing voltage and current losses, can cause electrical noise.
The majority of sites I have visited had incorrectly wired AC receptacles and were using light-duty use residential grade receptacles. Connecting a sensitive alarm system to these receptacles severely downgrades performance.
When did the electrical system last receive an upgrade or undergo a major modification? If you are not sure, ask yourself this question: How often are the same incandescent light bulbs replaced? If the answer is weekly, every two weeks, or even monthly, a serious problem may exist that requires immediate attention.
Is a lot of computer equipment installed throughout the building? If so, mutual interference, harmonic distortion, and neutral conductor heat buildup may occur. This type of inefficient operation can result in fires.
What kinds of electrical equipment are powered from the circuit-breaker panel serving the area where the alarm equipment will be installed? If large demand loads repeatedly turn on and off, consider selecting a different circuit-breaker panel or installing a new panel or a subpanel. If the panel directory is not marked, or worse, if it is improperly marked, the system may be connected to an incompatible power source.
What is the condition of the circuit-breaker panel that is to provide the electrical power to the console or other alarm components? If the panel is not properly maintained, problems may arise in getting the alarm system to operate correctly. …