Appendix A: Operating Temperature Measurement And Vertical Spacing; Operating Temperature; Baffles And Fan Trays - ABB CPS3200U Product Manual

Appendix A: Operating Temperature Measurement and
Vertical Spacing
Overview
The CPS3200U 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 CPS3200U 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 CPS3200U 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 65C 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 55C 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.
When mounting fan trays with converter shelves, leave no space between the top of a fan tray and the
converter shelf above it. The QS930A 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 QS931A 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.
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