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FireLite SLC Wiring Manual —
P/N 51309:R3
7/29/2019
SLC Circuits with Isolators
NFPA Class A SLC Using Isolator Modules
4.3 NFPA Class A SLC Using Isolator Modules
A variation of Class A operation using isolator modules to protect a section of the SLC. By flanking each group of devices with an I300
fault isolator module, each group is protected from faults that may occur in the other groups. For example, a fault in Section B will not
effect Sections A & C. The isolator modules on either side of Section B will open the loop. Section A will still operate from power on the
SLC Out side and Section C will operate from the SLC Return side.
•
A combination of isolator modules and isolator bases may be used.
•
T-tapping is NOT allowed within the Class A configuration.
•
Isolator modules shall be within 20 feet (6.1 meters) of device and must be enclosed in metal conduit.
Figure 4.5 NFPA Class A SLC Using Isolator Modules
SLC Out
SLC Return
SLC-style6
iso.wmf
Control Panel
Two-wire
Addressable
Detector
Section B
Section C
Section A
Isolator
Module
Isolator
Module
Isolator
Module
Additional isolator module required when first device in the
section is more than 20 feet from the control panel.
Isolator
Module
Isolator
Module
Isolator
Module
Addressable
Pull Station