Installation Wiring a Signaling Line Circuit (SLC)56 NFS-640 Installation Manual P/N 51332:B1 12/01/20033.10 Wiring a Signaling Line Circuit (SLC)OverviewCommunication between the control panel and intelligent and addressable initiating, monitor, andcontrol devices takes place through a Signaling Line Circuit (SLC). You can wire an SLC to meetthe requirements of NFPA Style 4, Style 6, or Style 7 circuits. This manual provides requirementsand performance details specific to this control panel; for installation information and generalinformation, refer to the SLC Wiring Manual.WiringMaximum 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.CapacityThe NFS-640 provides one (1) SLC, with a total capacity of 318 intelligent/addressable devices:• 01-159 intelligent detectors• 01-159 monitor and control modulesAn optional expander board provides one (1) additional SLC, with the same capacity.InstallationThis control panel supports one or two SLC loops; a second SLC loop is obtained by installing anLEM-320 module. SLC loop #1 connects to TB16 on the control panel; SLC loop #2 connects toTB1 on the LEM-320. For details on designing, installing and configuring SLC loops, see the SLCWiring Manual.Figure 34 SLC Loop Connections and WiringB+ A+ B- A- B+ A+ B- A-T-Tapping is not allowedon a four-wire SLC.SLC B (output loop)SLC A (loop return)SLC B SLC AStyle 4 SLC Loops Style 6 SLC LoopsTB1B+ A+ B- A-SLC1B+ A+ B- A-TB16SLC Loop #2 Connectionson Loop Expander ModuleSLC Loop #1 Connectionson FACP’s main circuit boardUse eitherSLC Loop #1or SLC Loop #2nfs640-slcloops.cdr, nfs640-slc-tb.cdr, LEM320-slc-tb.cdr
