Verilink AS2000: The Basics (880-502981-001) Product Manual - Manual (Page 35)

Site Planning
Verilink Access System 2000: The Basics 3-5
Heat Dissipation A fully loaded Multi-line Shelf with redundant power supplies
generates a maximum of 200 watts (680 BTUs). However, a full
shelf of DS3s may exceed this amount (dissipation must include
power supply losses.) A QLS generates 75 watts and a fully
assembled Dual-line Shelf with power supplies generates a
maximum of 22 watts (75 BTUs).
Figure 3-2 shows a variety of cooling options. Choose the option
that best fits your needs.
Heat Baffles If you have an MLS shelf above and an MLS shelf unit below, use a
heat baffle in the center to deflect the convected heat (
Figure 3-2 ,
A).
If you install (stack) two or more Quint-line or Dual-line shelf units,
Verilink recommends that you position a heat baffle between each
unit, or leave a space the size of a rack unit to dissipate the heat
(
Figure 3-2 , B).
CAUTION
The QLS and DLS do not have cooling vents at the bottom of their case,
and can overheat from a lack of cooling air if the top air vents are blocked.
Mount the heat baffle with the interior metal plate sloping up to the
rear of the shelf. Cooling air and heat flows are directed upward.
Fan Shelf A fan shelf is only required if you have an MLS populated with six
or more high-bandwidth modules (HDM 2180/2182). Use a fan shelf
above a single MLS (
Figure 3-2 , F) or between every two MLS units
( Figure 3-2 , C, D, E).
Shelf Cooling Limitations
If you do not have a cooling fan, provide an empty air space
between the component side of the HDM module (right side), and
the next module in the MLS. Without a fan, this limits the number
of HDM modules to six in an MLS, even with an NCM in slot 1.
Since a QLS can not use a fan shelf, you are limited to two HDM
modules (slots 2 and 4 only). In the DLS, only one HDM module is
permitted because of the power supply limitation.