Section 5: Slc Circuits With Isolators; Overview; Fault Isolator Modules - Honeywell Notifier AFP-100 Wiring Manual

Intelligent control panel slc

Table of Contents

5.1 Overview

There are two isolator devices used to protect critical elements of the FlashScan-mode or CLIP-mode SLC loop from faults on other SLC

branches or segments.

•

Fault Isolator Module ISO-X

•

Isolator Detector Base B224BI, B224BI-IV

•

Six fault isolator module ISO-6

To comply with NFPA Style 7 requirements, one of these devices must be used on both sides of a device: one isolator base and one iso-

lator module, two fault-isolator modules, or two circuits on a six-fault isolator module, for example.

A Fault Isolator Module on both sides of a device, or the combination of an Isolator and Isolator Module are required to comply with

NFPA Style 7 requirements. One isolator of ISO-6 meets the Isolator Module requirements. To comply with NFPA Style 7 requirements,

one of these devices must be used on both sides of a device: two fault isolator modules, one isolator base and one isolator module, for

example.

CAUTION: ISOLATOR LIMITS

IF RELAY OR SOUNDER BASES ARE NOT USED, A MAXIMUM OF 25 ADDRESSABLE DEVICES CAN BE

CONNECTED BETWEEN ISOLATOR MODULES AND/OR BASES. WHEN RELAY OR SOUNDER BASES ARE USED,

THE MAXIMUM NUMBER OF ADDRESSABLE DEVICES THAT CAN BE CONNECTED BETWEEN ISOLATORS IS

REDUCED TO SEVEN. ISOLATOR MODULES WILL NOT FUNCTION PROPERLY WHEN THESE LIMITS ARE

EXCEEDED.

WHEN MORE THAN 100 ISOLATOR MODULES AND/OR ISOLATOR BASES ARE CONNECTED FROM THE AFP-300

OR AFP-400 TO AN SLC LOOP, THE ADDRESS CAPACITY OF THE LOOP IS REDUCED BY TWO (2) ADDRESSES

FOR EVERY ISOLATOR DEVICE IN EXCESS OF 100. THE ADDRESS CAPACITY OF THE LOOP IS REDUCED BY

TWO (2) ADDRESSES FOR EVERY ISOLATOR DEVICE IN EXCESS OF 200 WHEN THE ISOLATOR MODULES

AND/OR ISOLATOR BASES ARE CONNECTED TO THE SLC LOOP FROM THE NFS-320, NFS-320SYS, NFS2-640,

NFS2-3030, NFS-3030, NFS-640, AFP-100, OR AFP-200.

5.2 Fault Isolator Modules

The ISO-X module continuously monitors the circuit connected to terminals 3(–) and 4(+). Upon powerup, an integral relay is latched

on. The module periodically pulses the coil of this relay. A short circuit on the SLC resets the relay. The module detects the short and dis-

connects the faulted SLC branch or segment by opening the positive side of the SLC (terminal 4). This isolates the faulted branch from

the remainder of the loop preventing a communication problem with all other addressable devices on the remaining branches (labeled

"Continuation of the SLC" in the figure below). During a fault condition, the control panel registers a trouble condition for each address-

able device which is isolated on the SLC segment or branch. Once the fault is removed, the module automatically reapplies power to the

SLC branch or segment. Figure 5.1 shows a Style 4 example for wiring of an Isolator Module. ISO-6 has the same functionality; see

Figure 5.2.