Juniper ACX1000 Hardware Manual page 54

Table 4: Alarm Relay Contact Functions
Contact Name Contact Name
Contact 1 Normally Open (NO)
Normally Closed
(NC)
Contact 2 Reference (REF)
Figure 9 on page 46 shows an example of a wiring diagram for a simple output alarm-reporting device.
In this case the device is a light bulb that illuminates when the device encounters a condition that
activates the red alarm LED and relay contacts. The alarm relay contacts can also be used to activate
other devices such as bells or buzzers.
Figure 9: Sample Output Alarm-Reporting Device
Function
Current is not flowing through Contact 1 and Contact 2 [REF] when
operating normally. When the current flows, the closed alarm is
generated.
Current is flowing through Contact 1 and Contact 2 [REF] when
operating normally. When the current stops flowing, the open alarm is
generated.
Provides the current path for the external alarm-reporting device and
functions as a reference or negative potential terminal for Contact 1.
46