Wiring The Alarm Relay - Panametrics Sentinel User Manual

Chapter 1. Installation
1.8.6

Wiring the Alarm Relay

The maximum electrical rating for the relay is listed in Chapter 7, Specifications. The alarm relay can be wired as
either Normally Open (NO) or Normally Closed (NC).
An alarm relay should be wired for fail-safe operation. In fail-safe mode, the alarm relay is constantly energized,
except when it is triggered or a power failure or other interruption occurs. See Figure 15 below for the operation of a
normally open alarm relay in fail-safe mode.
Connect the alarm relay in accordance with the wiring instructions shown on the label inside the enclosure #1 rear
cover (see Figure 13 on page xxvii and Figure 20 on page xxxviii). For wiring diagrams, see either Figure 22 on page xl
(AC) or Figure 23 on page xli (DC).
20
Fail-Safe
(not triggered)
NO
C
NC
ALARM
MONITORING
DEVICE
Fail-Safe
(triggered or power failure)
NO
C
NC
ALARM
MONITORING
DEVICE
Figure 15: Fail-Safe Operation
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