Fire-Lite Alarms MS-9200E Programming, Installation, Maintenance And Operating Instruction Manual page 32

Wiring the Signaling Line Circuit
Style 7 Four-Wire Communications Loop (Supervised and Power-limited)
The 4-wire communications loop meets NFPA 72 Style 7 requirements. By flanking each communications loop
device with a pair of I300 Fault Isolator Modules, each device is protected from short circuit faults that may occur on
other devices. For example, a fault on Zone 02 will not affect Zones 01 and 03. The isolator modules on either side
of Zone 02 will open the loop. Zone 01 will still operate from power on Loop Out and Zone 03 will operate from
Loop Return. Since the MS-9200 will no longer be able to communicate with Zone 02, a trouble signal(s) will be
generated for that device. No T-tapping or branching is allowed on this circuit. The ratings and characteristics are the
same as for a 4-wire circuit meeting NFPA Style 6 requirements.
4-Wire Communications Loop
FIGURE 2-13:
4
I300
Isolator Module
2
BG-10LX
4
I300
Isolator Module
2
CAUTION! Do not loop wiring under any termi-
nals. Break wire run to maintain supervision.
32
I300
Isolator Module
2
4
3
1
3
1
Protected Premises
Zone '01'
3
1
Shield
A
T
B
6
Connect Loop Out to TB6-3(+) and TB6-5 (-)
Connect Loop Return to TB6-4(+) and TB6-6(-)
I300
Protected Premises
Isolator Module
Zone '02'
4
3
SD300
Protected Premises
Zone '03'
B B+ A+ B- A-
1 2 3 4 5 6
Document #50428 Rev.C1 2/15/99
2
1
3 4
Isolator Module
1 2
3 4
Isolator Module
1 2
Note: Terminal designations are
shown for all I300 modules.
P/N 50428:C1
I300
CP300
I300