Panametrics Sentinel LCT, User Manual

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Sentinel LNG User’s Manual 25
Chapter 2. Installation
2.4.6 Wiring the Alarm Relay
Note: 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 16 below for the operation of a
normally open alarm relay in fail-safe mode.
Connect the alarm relay in accordance with the wiring instructions (see Figure 10 on page 20 and Figure 27 on
page 34). For a wiring diagram see Figure 28 on page 35.
Figure 16: Fail-Safe Operation
It is recommended to use 12-24 AWG (3.3 - 0.2 mm
2
) for single conductor wiring, and 16-24 AWG (1.5 - 0.2 mm
2
) for
two conductors per terminal.
NC
C
NO
ALARM
MONITORING
DEVICE
Fail-Safe
(not triggered)
(triggered or power failure)
Fail-Safe
DEVICE
MONITORING
ALARM
NC
C
NO