Chapter 2: Installation December 20, 2004
2-12 LTPH-UM-1261-01
Optional Fan Alarm Procedure
Figure 2-3. Alarms Wire-wrap Field (TB2)
Note: The FAN terminals wire-wrap field provides access to the Normally Open (NO), Form A fan relay
contact located on the HMU-319 management unit. A temperature monitor activates this fan relay when the
shelf temperature exceeds 45°C (±1°C) and deactivates the relay when the temperature drops below 35°C
(±1°C). If the temperature exceeds 77°C (±1°C) a critical alarm is also generated. The critical alarm resets
when the temperature drops below 40°C (±1°C).
Step Action
1 Connect the optional fan inputs to the Alarms wire-wrap field pins 25 and 26 (see Figure 2-3).
NC C NO
CRIT AUD
CRIT VIS
MAJ AUD
MAJ VIS
MIN AUD
MIN VIS
SYS ID
ACO
123
456
789
10 11 12
13 14 15
16 17 18
19 20 21
22
06-1261R1
ALARMS
23 24
GND
EXT
TEMP
25 26
NO COM
FAN