LaserFOCUS VLF-500 Product Guide
VESDA
®
12
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.
Figure 13 - 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.
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.
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.