Technical requirements for the connection of telecommunication equipment to the public mains - avoiding mains perturbations

The German manufacturer union (VDMA) and the utility union (VDEW) have agreed on the paper "Richtlinie fÿr den Anschluß von primÿr getakteten Schaltnetzteilen mit B6-Drehstromein-gang (Standard on the connection of switch-mode power supplies with B6-three-phase-input)", which are used in telephone centrals. This paper gives the relevant background information to calculate the required ratio of short circuit power of the mains and the rated of the telecommunication appliance depending on the harmonic content.