Xtralis VESDA E-Series, Manual

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VESDA Products
2-28 VESDA Student Workbook
VES sector addressability
• The VES detector draws air from all sectors in use and if the smoke level
reaches the Adaptive Scan Threshold it initiates a Fast Scan of each sector to
identify which sector is carrying smoke
• The first sector to reach the Alert Level is designated as the First Alarm Sector
(FAS) and this sector is signalled to the user
• If two or more sectors reach the Alert level, the sector with the highest smoke
concentration is designated as the First Alarm Sector (FAS)
• Once FAS is identified, the VES continues to monitor all sectors to track fire
growth and ultimately report Sector Fire Alarm to the panel
VLS scanner manifold design
• VLS incorporates a gear mechanism to
transfer DC motor rotation to valve shaft
through 90 degrees (rack and pinion) with
optical sensors to achieve “open” and
“closed” position
• Requires enough force via spring
compression through the shaft onto the pinion
to provide friction drive
• Requires precise manufacturing & assembly
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