A power conversion apparatus, such as a UPS, includes a DC link including first and second DC busses and a reference bus and a DC generator circuit coupled to the DC link and operative to generate first and second DC voltages with respect to the reference bus on respective ones of the first and second DC busses. The receptacle connector includes a receptacle housing having a top surface and a bottom surface, a support plate, spacers configured to retain the support plate adjacent to the top surface, and a post retained against the support plate by a spring and a fastener configured to releasable assemble the post and the support plate. The first electrode is electrically connected to the device control circuit, and the second electrode is electrically connected to the common interconnecting line through a contact hole. The crossover flange is configured for mechanically coupling the turbine housing to a crossover duct. During use, the user places a foot on the support rod. A method to digitally program the output impedance of a preamp write driver based on realistic operating data is also discussed.