VESDA VLF-500 Product Guide
VESDA by Xtralis
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www.xtralis.com
The AutoLearn Smoke LED will remain on for the duration of the AutoLearn process. At the start of the
process the alarm thresholds are set to the default values. During this learning cycle, alarm conditions can be
reported. If an alarm condition occurs (Alert or higher alarm) AutoLearn will not complete its cycle. In this
situation restart the AutoLearn process. If AutoLearn is stopped by you or due to an alarm condition, the alarm
thresholds will be left at the default settings.
Conditions during learning are assumed to be representative of normal operating conditions.
The AutoLearn Smoke learning times range from above 15 minutes to 15 days, with the default being set to 14
days.
If AutoLearn is running during the changeover period from Day and Night Thresholds function, make sure that
AutoLearn runs for at least an hour in both the Day and Night.
Alarm Level
AutoLearn Smoke Range
Alert
0.025 - 0.4 %obs/m (0.008 - 0.125 %obs/ft)*
Action
0.044 - 0.7 %obs/m (0.014 - 0.219 %obs/ft)*
Fire1
0.063 - 1.0 %obs/m (0.020 - 0.313 %obs/ft)*
Fire2
0.313 - 5.0 %obs/m (0.100 - 0.563 %obs/ft)*
Table 4-1: AutoLearn Smoke range
*For code-specific information, refer to Codes and Standards Information for Air Sampling Smoke Detection on page iii.
4.3
AutoLearn Flow
AutoLearn Flow process is initiated by pressing the recessed button numbered 2, which is located under the
field service access door. During the AutoLearn Flow process, the VESDA VLF determines the average and
peak air flow levels monitored over time and sets suitable air flow thresholds that will not give rise to false flow
rates due to normal flow variations (such as might arise through air-conditioning related false alarms). The
system will normalize the flow and then monitor the flow trend to set the flow fail thresholds.
The AutoLearn Flow indicator LED will remain on for the duration of the AutoLearn process. At the start of the
process the flow thresholds are set to the default values. During this learning cycle, alarm conditions can be
reported. If a flow fault is reached, AutoLearn will not complete its cycle. In this situation restart the AutoLearn
process. If AutoLearn is stopped by you or due to a flow fault condition, the flow thresholds will be left at the
default settings.
Conditions during learning are assumed to be representative of normal operating conditions.
The AutoLearn Flow learning times range from 15 minutes to 15 days, with the default being set to 14 days.
4.4
Xtralis VSC
Xtralis VSC is an optional software application that allows all VESDA detectors to be configured. All
parameters can be set manually or previously saved configuration settings may be applied. Refer to the
Xtralis VSC online help for details regarding the setting of these thresholds.
4.5
Commissioning smoke test
It is recommended that a smoke test be carried out to prove the integrity of the pipe network, to demonstrate
that the system is working and to measure the transport time to the detector.
This test involves introducing a smoke sample at the furthest sampling hole and then measuring the time
taken for the smoke to travel to the detector. Results are logged and compared to subsequent tests to note
variations of the system.
Refer to the VESDA System Design Manual for details of the commissioning smoke test.
