Nortel DMS-100 Series Maintenance Manual page 655

Secondary (diffuser) filter replacement in cooling unit
Exhaust ports
Fans
Diffuser (secondary)
filter
ECU
Insect
screen
3
4
5
6
Clean or replace the filter.
Insert the cleaned filter or replacement filter in the ECU.
Set the ECU fan switch to ON.
This replacement procedure is complete.
DMS-100 Family OPM Maintenance Manual XPM14 and up
OPM routine maintenance procedures 13-53
OPM
(end)
Exhaust ports
Insulation
Batteries
Electronic
equipment
ECU fans
Heater pads
and damper
Primary
filter
Air intake