Castlet started by designing three independent transformer rectifier units typically rated at 90V / 500A DC. Our client tried to fit the three units into the available space by the use of CAD. After repeated attempts by our client to make the entire equipment ft into the limited space, it was eventually decided that this was not possible.

We were then asked to look at alternative solutions, and came up with an alternative design which was for a three in one package. This was for a single enclosure with three compartments, separated by a perforated mesh side walls. Each section had its own door, incoming electrical isolation, TR unit and heat exchanger. The centre section also incorporated an overall electrical isolation point for all three sections. The cooling water inlet was via a single pair of flanged joints connected to an internal water pipe system. This pipe system was the feed to all three heat exchanges, which were also fitted with a pair of isolation valves for maintenance purposes. The further financial benefit of this design was that due to there being a single enclosure there was only a requirement to install a single larger air purge unit, with a further reduction in cost due to only a single zone one certification being required.