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19. Signal Supply Voltage Options
19.1 Standard Systems With Combined Logic And Signal Supply.
In standard systems the 24VDC logic supply, OV and +V is cross-linked to the signal supply input
terminals, OVC and +VC to provide the voltage required to power the input contacts. Systems are
supplied with a factory fitted jumper between these terminals.
The signal supply input teVC is used to internally link 24VDC Via a fuse to all of the common
terminals within the annunciator marked “C” ready for connection to customer signal contacts
Systems Using A Single 24VDC For Logic And Signal Supply
FR
MULT
SUPPLY 24VDC
HNB
HNA
T
A
ST
R
M
SPR
GPA GPB
24VDC LOGIC
SUPPLY
1 C 2 C
INTERNAL DISTRIBUTION OF
SIGNAL SUPPLY VOLTAGE
INTERNAL
1A SIGNAL
SUPPLY FUSE
OV
+V
OVC
+VC
Earthing
All NEX725 Series Alarm Annunciators are fitted with a separate earth stud, which is located on the
metal enclosure.
Warning:-
To ensure the final installation meets all relevant Zone 2 safety standards and EMC
directives this earth must be connected
