Form-C Operation; Typical Form-A And Form-C (Kyz) Connections; Example Of Detection Of A Form-C Fault - Honeywell CNI2 Operating And Installation Manual

CNI2 Operating and Installation Guide

FORM-C OPERATION

Typical Form-A and Form-C (KYZ) Connections

A Form-C (KYZ) switch is often used so that a defective switch or associated wiring can be
detected. In the illustration alarm sensing or pulse counting is performed on the "INPUT-1"
connection only. "INPUT-2" is used for fault detection.
The switches should never be open or closed at the same time. If so the CNI2 will report an
alarm condition. The next figure shows how a KYZ fault is detected.

Example of Detection of a Form-C Fault

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