Appendix A: Operating Temperature Measurement And Vertical Spacing - ABB CPS2400U Product Manual

Appendix A: Operating Temperature Measurement and
Vertical Spacing
Overview
The CPS2400U has been designed for mounting in relay racks or in equipment cabinets. It is designed
for use with user provided vertical airflow cooling of at least 175 linear feet per minute over the entire
flow cross-section of the shelf. Equipment may be placed on top of the CPS2400U provided airflow is
not impeded or sufficient spacing is provided. A 1U Baffle is required above the highest converter shelf;
this baffle provides sufficient vertical spacing. Direct the airflow into a 3 inch minimum space. If the
spacing is less than 3 inch spacing application specific testing is required.
Operating Temperature
The CPS2400U is rated to work to 65 C in stacks of two shelves in outdoor cabinets without baffles.
Note: in outdoor cabinets where the air entering the second shelf may be heated above 65°C inlet
temperature, additional airflow beyond the 175 linear feet per minute is required. These cases require
an engineered solution.
In Central Office environments when baffles are required for safety reasons, a three shelf system is
rated to operate in 55°C environments.
Baffles and Fan Trays
For Central Office applications, baffles are used between every set of three Converter shelves. Fan
Shelves are required for every set of three Converter shelves. No more than 6 shelves may be located in
a particular frame. Slot covers must be used on all empty slots when more than one shelf is being
cooled by a particular airflow device.
Always mount converter shelves above the fan tray that cools them.
Leave no space between the top of a fan tray and the converter shelf above it. The Fan Shelf draws air
down through whatever equipment is located directly above it. If a gap is left above a fan tray, air will
be drawn into the fan tray from the aisles rather than from the converter shelf above the fan tray. This
will result in service effecting problems due to insufficient cooling air flowing through the active
converters.
The Fan Shelf forces air up through whatever equipment is located directly above it. If a gap is left
above a fan tray, air will escape into the aisles rather than flowing into the converter shelf above the fan
tray. This will result in service effecting problems due to insufficient cooling air flowing through the
active converters.
Always mount a converter shelf immediately above a fan shelf or above a converter shelf stacked on a
fan shelf. Any gaps between converter shelves, or absence of slot covers, can cause service effecting
problems.
Note: All unpopulated converter slots must be filled with slot fillers. For example the figure below
shows a shelf with operational converters in the first two slots and slot fillers in the remaining 10 slots:
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