
FireLite SLC Wiring Manual —
P/N 51309:R3
7/29/2019
27
NFPA Class X SLC Using Isolator Modules
SLC Circuits with Isolators
4.4 NFPA Class X SLC Using Isolator Modules
Class X operation requires using isolator modules (or a combination of isolator modules and isolator bases) before and after each device.
Flanking each device with an isolator provides fault protection to all other devices on the loop.
•
T-tapping is NOT allowed within the Class X wiring configuration.
•
When a detector base or pull station is used, install isolator modules on both sides of the device.
•
Connections between isolator modules and the device they isolate must be “close-nippled” conduit, within 3 feet (91.44 cm).
2
1
3
4
3
4
3
4
1
3
1
3
2
1
2
1
SL
C-
st
yl
e
7
iiso.
w
mf
SLC Out
SLC Return
Two-Wire
Addressable
Detector
Addressable
Pull Station
Control Panel
Two-wire
Addressable
Detector
Figure 4.6 NFPA Class X SLC Using Isolator Modules
Isolator
Module
Isolator
Module
Isolator
Module
Isolator
Module
Isolator
Module
Isolator
Module
Isolator
Module
Isolator
Module