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Warning Limitations of This Alarm System
While this system is an advanced design security system, it does not offer guaranteed protection against
burglary, fire, or other emergency. Any alarm system, whether commercial or residential, is subject to
compromise or failure to warn for a variety of reasons. For example:
• Intruders may gain access through unprotected openings or have the technical sophistication to
bypass an alarm sensor or disconnect an alarm warning device.
• Intrusion detectors (e.g., passive infrared detectors), smoke detectors, and many other sensing
devices will not work without power. Battery-operated devices will not work without batteries, with dead
batteries, or improperly installed batteries. Devices powered solely by AC will not work if their AC
power supply is cut off for any reason, however briefly.
• Signals sent by wireless transmitters may be blocked or reflected by metal before they reach the alarm
receiver. Even if the signal path has been recently checked during a weekly test, blockage can occur if
a metal object is moved into the path.
• A user may not be able to reach a panic or emergency button quickly enough.
• While smoke detectors have played a key role in reducing residential fire deaths in the United States,
they may not activate or provide early warning for a variety of reasons in as many as 35% of all fires,
according to data published by the Federal Emergency Management Agency. Some of the reasons
smoke detectors used in conjunction with this system may not work are as follows: Smoke detectors
may have been improperly installed and positioned. Smoke detectors may not sense fires that start
where smoke cannot reach the detectors, such as in chimneys, in walls or roofs, or on the other side
of closed doors. Smoke detectors may not sense a fire on another level of a residence or building. A
second-floor detector, for example, may not sense a first-floor or basement fire. Moreover, smoke
detectors have sensing limitations. No smoke detector can sense every kind of fire every time. In
general, detectors may not always warn about fires caused by carelessness and safety hazards like
smoking in bed, violent explosions, escaping gas, improper storage of flammable materials,
overloaded electrical circuits, children playing with matches, or arson. Depending on the nature of the
fire and/or the location of the smoke detectors, the detector, even if it operates as anticipated, may not
provide sufficient warning to allow all occupants to escape in time to prevent injury or death.
• Passive infrared motion detectors can detect intrusion only within the designed ranges as diagrammed
in their installation manual. Passive infrared detectors do not provide volumetric area protection. They
do create multiple beams of protection, and intrusion can be detected only in unobstructed areas
covered by the beams. They cannot detect motion or intrusion that takes place behind walls, ceilings,
floors, closed doors, glass partitions, glass doors, or windows. Mechanical tampering, masking,
painting, or spraying of any material on the mirrors, windows, or any part of the optical system can
reduce their detection ability. Passive infrared detectors sense changes in temperature; however, as
the ambient temperature of the protected area approaches the temperature range of 90° to 150°F, the
detection performance can decrease.
Warnings and Limitations
A P P E N D I X