VESDA by Xtralis
VESDA VLC-400 Product Guide
www.xtralis.com
29
8
Commissioning
8.1
Device Commissioning
All commissioning activity for the VESDA VLC-400 detector is performed via Xtralis VSC.
Note:
Connecting Xtralis VSC causes the VESDA VLC-400 to be disconnected from the fire loop. A
Communications fault is generated and the fire panel sees the detector as being in a fault condition.
8.2
Factory default user access levels
The factory set default access levels are:
l
User (USR)
l
Administrator (ADM)
l
Distributor (DST)
Note:
Only authorized personnel at the Administrative (ADM) or Distributor (DST) level may alter these
values.
Each level requires a four-digit Personal Identification Number (PIN) to be entered before gaining access to
the detector. The user may add, alter, delete or modify user names or PIN's after gaining access to the
system. Up to 10 Users and four Administrators may be added.
8.3
Checks prior to power up
Prior to powering up the detector ensure the checks as per Chapter 7 have been performed.
8.4
Powering up sequence
When the VESDA VLC-400 is powered up, the LED's are illuminated in a specific test sequence. During the
test sequence all LED’s are operated – if any fail to operate the reasons must be investigated.
The aspirator will start several seconds after power is applied and assuming no previous commissioning, an
airflow fault will be reported within two minutes because the flow has not been “normalized”. A normalization
operation must be performed to eliminate this fault. Refer to Section 8.6 for a description of the normalization
process.
8.5
Setting smoke thresholds
The smoke threshold is set using Xtralis VSC. Refer to the Xtralis VSC user documentation for details on how
to set the smoke thresholds, or refer to Section 2.5.6 Sensitivity modes above.
Smoke thresholds can be set in one of three ways:
1. The default Fire threshold of 0.2% obs/m may be used for all standard design configurations as each hole
has a sensitivity better than 4.5% obscuration/m (and provide EN54-20:Class B sensitivity). However,
this may not achieve the optimum levels of protection possible.
2. The system can be set in AutoLearn to achieve optimum levels of protection. This learning algorithm runs
for a maximum of 14 days and monitors the background levels, setting the alarm threshold at an
appropriate level above the normal background. Refer to Section 8.6.
3. Customised thresholds can be set using a PC running Xtralis VSC.
Customised thresholds may be appropriate in particular circumstances but should be used with caution. For
example, the default alarm threshold of 0.2% may be inappropriate for a system protecting a small area (using
fewer holes than the maximum allowed) with a background level around 0.15% obscuration/m. In this situation
a Fire threshold > 0.2% obscuration/m may be appropriate. However, as a general rule, the maximum Alarm
threshold needed to ensure a given EN54-20 sensitivity Class is given by the following expression:
l
Class C threshold < 6/ N % obscuration/m
l
Class B threshold < 3 / N % obscuration/m
l
Class A threshold < 1 / N % obscuration/m
