The Isolator Module; Module Addressing - Fire-Lite Alarms MS-9200 Technical Manual

2.8 2.8

The Isolator Module

The Isolator Module
2.8 2.8 The Isolator Module 2.8 The Isolator Module The Isolator Module
The Loop Isolator Module (I300) is used to protect critical elements of the communications loop from faults on other
branches or sections of the loop. The I300 continuously monitors the circuit con-
nected to terminals 1 (-), 3 (-), 2 (+) and 4 (+). Upon power-up, an integral relay is
latched on. The I300 periodically pulses the coil of this relay. A short circuit on
either side of the loop resets the relay. The I300 senses the short and disconnects
the faulty branch by opening the positive side of the loop (terminal 2 or 4). This
effectively isolates the shorted branch from the remainder of the loop. Once the
fault is removed, the I300 automatically reapplies power to the communications
loop branch. Figure 2.7 illustrates the use of an I300 on a two wire communications
loop meeting NFPA Style 4 requirements; Figure 2.9 shows a four wire loop
meeting NFPA Style 7 requirements.
Note: Note:
Note: Note: Note:
During a fault condition, the MS-9200 will register a trouble condition for each device isolated on the loop
branch.
Figure 2.13: Isolating Two-Wire Communications Loops Figure 2.13: Isolating Two-Wire Communications Loops Figure 2.13: Isolating Two-Wire Communications Loops
Figure 2.13: Isolating Two-Wire Communications Loops Figure 2.13: Isolating Two-Wire Communications Loops
A short on any T-tapped branch off an I300 Isolator Module on the Communication Loop meeting NFPA Style 4 wiring
requirements, will be isolated from all devices installed both upstream of the I300 (Communications Loop In) and on
the continuation of the loop (shown as a dotted line). As an example, if a short were to occur on Branch A of the first
I300 shown, the isolator module would disconnect Branch A and its devices from the rest of the Communication Loop,
allowing all devices connected before and after that I300 to operate normally.
Communications Communications Communications Communications Communications
Loop In Loop In Loop In Loop In Loop In

2.9 Module Addressing

2.9 Module Addressing 2.9 Module Addressing 2.9 Module Addressing 2.9 Module Addressing
Monitor and Control Modules have two rotary decimal switches which are used by the installer to set the module
address. Addresses from 01 to 99 may be set by positioning the left rotary switch to the value of the '10's
digit and the right switch to the value of the '1's digit. For example, address 31 would be set by pointing the left switch
to 3 and the right switch to 1 as shown below.
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Continuation of the Communications Loop Continuation of the Communications Loop Continuation of the Communications Loop Continuation of the Communications Loop Continuation of the Communications Loop
I300 I300 I300 I300 I300
Branch A Branch A Branch A Branch A Branch A
T-Tapped Branches off the Communications Loop T-Tapped Branches off the Communications Loop T-Tapped Branches off the Communications Loop T-Tapped Branches off the Communications Loop T-Tapped Branches off the Communications Loop
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2
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Branch B Branch B Branch B
Branch B Branch B
4 4
5 5
3
6 6
2
7 7
8 1
8
0 9 0
9
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Loop In ( - )
Loop In ( + ) I300 I300
I300 I300 I300
Loop Out ( - )
Loop Out ( + )
I300 I300 I300 I300 I300