Instruction Manual

Installation Wiring a Signaling Line Circuit (SLC)
54 NFS-640 Installation Manual P/N 51332:B2 07/27/2004
3.10 Wiring a Signaling Line Circuit (SLC)
Overview
Communication between the control panel and intelligent and addressable initiating, monitor, and
control devices takes place through a Signaling Line Circuit (SLC). You can wire an SLC to meet
the requirements of NFPA Style 4, Style 6, or Style 7 circuits. This manual provides requirements
and performance details specific to this control panel; for installation information and general
information, refer to the SLC Wiring Manual.
Wiring
Maximum wiring distance of an SLC using 12 AWG (3.1 mm
2
) wire:
• Style 4 -12,500 feet (3810 meters) total twisted-pair.
• Style 6 & 7 -10,000 feet (3048 meters) total twisted-pair.
Capacity
The NFS-640 provides one (1) SLC, with a total capacity of 318 intelligent/addressable devices:
• 01-159 intelligent detectors
• 01-159 monitor and control modules
An optional expander board provides one (1) additional SLC, with the same capacity.
Installation
This control panel supports one or two SLC loops; a second SLC loop is obtained by installing an
LEM-320 module. SLC loop #1 connects to TB16 on the control panel; SLC loop #2 connects to
TB1 on the LEM-320. For details on designing, installing and configuring SLC loops, see the SLC
Wiring Manual.
Figure 34 SLC Loop Connections and Wiring
B+ A+ B- A- B+ A+ B- A-
T-Tapping is not allowed
on a four-wire SLC.
SLC B (output loop)
SLC A (loop return)
SLC B SLC A
Style 4 SLC Loops
Style 6 SLC Loops
TB1
B+ A+ B- A-
SLC1
B+ A+ B- A-
TB16
SLC Loop #2 Connections
on Loop Expander Module
SLC Loop #1 Connections
on FACP’s main circuit board
Use either
SLC Loop #1
or SLC Loop #2
nfs640-slcloops.cdr, nfs640-slc-tb.cdr, LEM320-slc-tb.cdr
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