Electrical Specifications Wire Requirements
78 NFS-640 Installation Manual P/N 51332:B1 12/01/2003
Note: Lightning arresters required on circuits extending between buildings; 999 meter length
maximum to meet UL 1459.
Table 16 Wire Requirements
Circuit
Type
Circuit
Function Wire Requirements
Distance
(feet/
meters) Typical Wire Type
SLC
(power limited)
Connects to
intelligent and
addressable
modules.
Twisted-unshielded pair, 12 to 18 AWG
(3.1 to 0.78 mm
2
). 50 ohms maximum
per length of Style 6 & 7 loops. 50 ohms
per branch maximum for Style 4 loop.
12,500/3,810
8,000/2,438
4,875/1,486
3,225/983
12 AWG (3.1mm
2
)
14 AWG (2.00mm
2
)
16 AWG (1.30mm
2
)
18 AWG (0.78mm
2
)
or Untwisted, unshielded wire, in conduit
or outside of conduit.
Note: Maximum total capacitance of all SLC
wiring (both between conductors and from any
conductor to ground) should not exceed 0.5
mircofarads.
1,000/304.8
12 to 18 AWG (3.1 to 0.78 mm
2
)
EIA-485
(power limited)
Connects to
LCD-80, ACS
modules, or
TM-4
Transmitter
Twisted-shielded pair with a
characteristic impedance of 120 ohms.
18 AWG (0.78 mm
2
) minimum.
6,000/1829
(max)
16 AWG (1.30mm
2
)
EIA-232
(power limited)
Connects to
Printers, CRT,
or PC.
Twisted-shielded pair.
18 AWG (0.78 mm
2
) minimum.
50/15.24
(without modem)
16 AWG (1.30mm
2
)
IDC
Initiating
Device Circuit
FMM-1 , FMM-
101XP5-M
(power limited)
12-18 AWG (3.1 to 0.78 mm
2
).
Maximum circuit resistance is 20 ohms.
12 to 18 AWG (3.1 to 0.78 mm
2
)
NAC
Notification
Appliance
Circuit
XP5-C, FCM-1
(power limited)
12-18 AWG (3.1 to 0.78 mm
2
).
At alarm current level, no more than a
1.2 V drop at the end of the circuit, or
sized to provide the minimum rated
operating voltage of the appliances
used.
To meet 1.2 V
drop, or sized to
provide the
minimum rated
operating voltage
of the appliances
used.
12 to 18 AWG (3.1 to 0.78 mm
2
)
24 VDC Power
Runs
(power-
limited)
To TM-4
Transmitter,
Annunciator
and FCM-1
modules
12-18 AWG (3.1 to 0.78 mm
2
).
Size wire so that no more than 1.2 V
drop across wire run from supply source
to end of any branch.
To meet 1.2 volt
drop
12 to 18 AWG (3.1 to 0.78 mm
2
)
CHG-120 External
battery
charger
12 AWG (3.1 mm
2
) in conduit
20/6.1 (max)
12 AWG (3.25mm
2
)