Nortel DMS-100 Series Maintenance Manual page 665

Testing heaters in an OPM
At the OPM cabinet
1 Cool the low temperature heater switch located in the environmental control
unit (ECU) with Freon. Refer to the following figure for sensor location:
High
temperature
Fuse
alarm
panels
Empty
or
LCA-0
HIE
ECU
BAY 0
Low
temperature
heater switch
2 Make sure that the heat blanket turns on. The heat blanket turns ON at +5°C
± 2.8°C (+41°F ± 5°F) and turns OFF at +15°C ± 2.8°Χ (+59°F ± 5°F).
If the heat blanket
turns ON
does not turn ON
Bay locking
knobs
B
LCA
C
C
Low temperature
Bay locking
heater switch
knobs
DMS-100 Family OPM Maintenance Manual XPM14 and up
OPM routine maintenance procedures
High temperature
alarm
B
C
Rectifiers
C
and PCU
FSP
RMM
ECU
BAY 1
Damper
control
sensors
Do
step 4
step 3
13-63
Heaters testing
OPM
(continued)
Doors
switch
Low temperature
alarm sensors (each
ECU)