A direct current to alternating current inverter sub-system is for a HVDC distribution system. A second calculation part calculates the phase-to-phase residual magnetic flux of the three phases in the primary windings side of the transformer when the circuit breakers interrupt the transformer. The coupling member may be configured to provide a sealing engagement between the coupling member and the jumper tube at the first end, and the coupling member may be configured to provide a sealing engagement between the coupling member and the plurality of jumper tubes at the second end. % of a polymer based on weight of said asphalt cement, and vulcanizing the polymer-containing asphalt cement. The idea on which this invention is based consists in replacing expensive tools of special steel previously used for holding dimensionally unstable prepreg fabrics with at least one holding part of composite fiber materials, wherein the at least one holding part has a lower hardening temperature than the prepreg fabric, and can therefore be produced with a lower cost tool. Controller data, including operational parameter values and module setup values, is accessible while the transceiver operates in conjunction with an external host and may be retrieved, and sometimes modified, in real time without interrupting normal transceiver operation or suspending the transmission of data over optical fibers.