VESDA by Xtralis
VESDA VLC-EX Product Guide
www.xtralis.com
25
7
Power Source
The power terminals on the termination card connect to a 24 VDC power supply. The detector has reverse
polarity protection to minimize the risk of damaging the detector.
Notes:
l
The VESDA VLC-EX detector will not operate when the power supply is reversed.
l
Operating the detector outside the DC supply voltage range of 18 VDC and 30 VDC may cause damage
to the device.
l
The VESDA VLC-EX is provided with an additional transorb wired into the power terminals a shown in
Figure 7-1. This transorb must have a clamping voltage of 55V or less and an breakdown voltage of 33V
or more (Part number 3KP33CA from Littlefuse is a suitable example). This transorb must be fitted to
ensure compliance with Clause 13 of EN60079-15:2010.
7
8
A
-
+
B
+24V
GND
9
10
-
+
24V POWER
Legend
A
24V Power
B
Transorb for additional transient
protection
Figure 7-1: Wire connection details for the power terminals on the VN and RO model termination card
Note:
The PSU is usually located in a non-hazardous area and may supply power via a Zener barrier (or
other similar energy limiting device) but this is not required for safe operation of the VESDA VLC-
EX in normal operation. Refer to the notes in Section 6.1 for further information.
Summary of Contents for VESDA VLC-500-EX
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