ADC HiGain HMS-318 List 3 User Manual page 18

Chapter 1: Product Description
Alarms Wire-Wrap Field
Before making power connections (CO primary power feeds A and B) to the HMS-318 List 3 shelf,
IMPORTANT
ensure that the Main CO power breaker is off. Otherwise, severe injury to the installer or damage
!
to the unit may result.
Terminate the alarm leads from the CO alarm system to the HMS-318 List 3 shelf. The Alarms wire-wrap field (TB2,
see Figure 1-2) is a 26-pin wire-wrap connector and provides a central connection point to the Normally Closed
(NC), Common (COM), and Normally Open (NO) relay contacts for installing optional alarm input connections (see
Table 1-1 on page 1-4 for Alarm descriptions). When an alarm is not active, there is continuity between the NC and
COM connections; when an alarm is active, there is continuity between the NO and COM connections.
Note: The NO and COM alarm relay connections can be daisy-chained between HMS-318 List 3 shelves
for multi-shelf applications in the same equipment rack.
Alarm Cutoff (ACO)
The Alarm Cutoff (ACO) function silences active audible alarms. Alarm cutoff can be achieved by pressing the ACO
button on the front panel of the Management Unit (for example, HMU-319) or by connecting the ACO pin 22 on the
HMS-318 List 3 shelf Alarms wire-wrap field (see
external NO push button switch. The ACO lead can be daisy-chained to other shelves for multi-shelf applications in
the same equipment rack.
1-6
ALARMS
NC C NO
CRIT AUD
CRIT VIS
MAJ AUD
MAJ VIS
MIN AUD
MIN VIS
SYS ID
ACO GND E XT
TEMP
NO COM
FAN
Figure 1-4. Alarms Wire-Wrap Field (TB2)
Figure 1-4
1 2 3
5
4 6
7
8 9
10 11 12
13 14 15
16 17 18
19 20 21
22 23 24
25 26
on this page and Table 1-2) to ground through an
December 20, 2004
LTPH-UM-1261-01