Installation
3-153000-A2-GA31-80 December 1994
Fan Module Installation
For installations where the ambient temperature is
likely to be near the upper limit of the acceptable range
(see Table 3-1), a fan module must be added to the carrier
to provide forced air cooling.
Preinstallation Inspection
Check the unit for physical damage, such as broken
blades. Spin fan blades manually to test for damage. If the
fan module shows signs of damage, report this
immediately to your shipping representative and also to
your AT&T Paradyne representative. Otherwise, install
the fan module.
Installation
The optional fan module is connected to the power
transformer unit; therefore, this procedure assumes the
power transformer unit has been installed.
To install the fan module:
Procedure
1. If the fan module is being installed after the carrier
has been installed, loosen the four captive screws
(see Figure 3-10) that attach the cover plate to the
carrier and remove the cover plate. If an SDCP is
not being installed, set the cover plate aside for
reinstallation after the fan module has been
installed.
Table 3-1
Fan Module Cooling Requirements
Ambient
Temperature
Circuit Card
1
Number of Carriers
Temperature
Range
CcuCad
Configuration11 – 2 3 4 5 – 6
F
DSUs without
DBMs and Model
3151 CSUs No Fan Modules 1 fan module
(place in second
carrier from top)
39 – 86 F
(4 – 30 C)
DSUs with DBM,
and Model 3811
and 3911 dial/
lease modems 2
No fan modules 1 fan module
(place in middle
carrier)
2 fan modules
(place in bottom
carrier and
second from top) 1 fan module
per carrier
Model 3161 DSU/
CSUs 21 fan module per carrier or 1 fan module
per two carriers (placed in upper carrier)
per carrier
86 – 122 F
(30 – 50 C) Model 3161 DSU/
CSUs 21 fan module per carrier
(Limit of 3 carriers in a cabinet at temperatures above 40 C or 104 F) 3
1 Installing the TDM or MCMP option has no effect on this table.
2 Use the strictest cooling requirements when there is a mixture of units installed.
3 Allow 1.75″ (IU) spacing between carriers if more than 3 carriers are required.