Fire-Lite Alarms MS-9200UD, Manual

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Operating Instructions Read Status
152 MS-9200UD PN 51906:A 12/10/02
Drift Compensation
Drift compensation uses software algorithms that identify and compensate for long-
term changes in the data readings from each addressable smoke detector. These long-
term changes in detector data readings are typically caused by dirt and dust
accumulation inside the smoke chamber. Drift compensation performs the following
functions:
• Allows a smoke detector to retain its original ability to detect actual smoke and
resist false alarms, even as dirt and dust accumulate
• Reduces maintenance requirements by allowing the control panel to
automatically perform the periodic sensitivity measurements required by NFPA
Standard 72
The FACP software also provides filters to remove transient noise signals, usually
caused by electrical interference.
Maintenance Alert
The software determines when the drift compensation for a detector reaches an
unacceptable level that can compromise detector performance. When a detector
reaches an unacceptable level, the control panel indicates a maintenance alert. Table
4.1 summarizes the three levels of maintenance alert:
Figure 4.1 illustrates a graphic representation of the maintenance levels:
Maintenance Level FACP Status Displays Indicates
Low Chamber Value
INVREP
A hardware problem in the detector
Maintenance Alert
DIRTY1
Dust accumulation that is near but below the
allowed limit.
DIRTY 1 indicates the need for
maintenance before the performance of the detector
is compromised
Maintenance Urgent
DIRTY2
Dust accumulation above the allowed limit.
Table 4.1 Maintenance Alert Levels
Figure 4.1 Diagram of Maintenance Levels
DIRTY
Acceptable
Range
Maintenance
Urgent
Maintenance
Alert
Low Chamber
Reading
LOW
VALUE