Notifier AM2020 User Manual

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Installation 15088: J 10/22/99
Section 4.5 The Isolator Module
The Loop Isolator Module, ISO-X (refer to Figures 4.5-1 through 4.5-3), is used to protect critical elements of
the SLC from short circuit faults on other branches or sections of the loop.
ISO-X
SLC Loop In ( - )
SLC Loop In ( + )
SLC Loop Out ( - )
SLC Loop Out ( + )
Figure 4.5-1 The Loop Isolator Module (ISO-X)
The ISO-X continuously monitors the circuit by pulsing the coil of an integral relay which is latched on at power
up.
Continuation of the SLC
T-Tapped Branch off the SLC
ISO-X
SLC
Loop
Figure 4.5-2 Isolating a Branch of a Style 4 SLC
The ISO-X sees this short and disconnects the faulted branch, effectively isolating the faulted branch from the
remainder of the loop (refer to Figure 4.5-3). Once the fault is removed, the ISO-X reapplies power to the loop
branch. Figures 4.5-1 through 4.5-3 illustrate the use of ISO-Xs on Style 4 SLCs. For an example of employing
ISO-Xs on Class A SLCs (refer to Figure 4.3-5).
Shorts on the remainder of this NFPA Style 4 SLC will
be isolated from all devices installed upstream of the
ISO-X.
Remainder of the SLC
ISO-X
SLC
Loop
Shorts on this T-tapped branch of an NFPA Style 4 SLC
will be isolated from all devices installed on the SLC
connected to terminals 1 and 2 of the ISO-X. A short or
open on the T-tapped branch will result in loss of
communication to the devices on that branch. The T-
tapped branch will be isolated from the remainder of the
SLC.
Figure 4.5-3 Isolating the Remainder of a Style 4 SLC
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Notifier AM2020 Specifications

General

Brand	Notifier
Model	AM2020
Category	Fire Alarms
Language	English