VESDA by Xtralis
VESDA VLF-500 Product Guide
www.xtralis.com
15
2.7.5
Relays (Terminals 12 - 20)
The relays allow alarm and fault signals to be hard wired to external devices, such as fire alarm control panels
and loop interface modules away from the detector (example, sounding a siren at Action threshold). Refer to
the appropriate installation manual for connectivity instructions.
Legend
12
NC
Fault Relay
13
Common
14
NO
15
NC
Action Relay
16
Common
17
NO
18
NC
Fire 1 Relay
19
Common
20
NO
NC
Normally closed
contact of relay (with
no power applied).
NO
Normally open contact
of relay (with no power
applied).
Common
Common contact for
the relay.
Figure 2-12: Terminal block display, relays
Note:
By default, the Fault relay is normally energized when no fault is present. For example when there
is no fault present, terminal 12 is held open and terminal 14 is held closed. When there is a fault
present, terminal 12 is held closed and terminal 14 is held open.
2.7.6
Typical Wiring To Fire Alarm Control Panel (FACP)
The diagram below shows the correct way to wire VESDA detectors to a conventional fire alarm control panel
(FACP). It also shows where an End Of Line (EOL) resistor is correctly installed.
Figure 2-13: Typical wiring to a fire panel with EOL
