Development of a passively cooled outdoor telecom power enclosure

This paper documents the development of a passively cooled outdoor electronics enclosure consisting of six 1.2kW AC/DC rectifiers (7.2kW total output power). Commercially available fan cooled rectifiers were used as a starting point and modified to be passively cooled using heat pipes and naturally-cooled heat sinks without changing the layout of the original circuit board. Several designs were considered, tested and modified to develop a fully passive thermal solution. The prototype was tested at ambient air temperatures of 26°C, 36°C and 46°C and it delivered 98.8%, 85.7% and 80.7% of its nominal output power at each of these temperatures, respectively.