Question:
How can 230 V inverters be supplied from a three-phase mains (e.g. 3 x 400 V) without N (neutral)?
Answer:
Solution A)
Use autotransformer, prim.:1 x 400 V (mains L1-L2), sec.: 1 x 230 V.(inverter L1-N). If the load of all three mains phases is necessary and at least three inverters are used, three separate autotransformers are required (Tr.1 = L1-L2, Tr.2 = L2-L3, Tr.3 = L1-L3).
Note: Only those inverters connected to the same transformers can be operated in a DC bus network.
Solution B)
When at least 3 inverters of 8200 series as from version 2 are used a three-phase autotransformer (prim.: 3x400V, sec.: 3x230V, Y-connection) is possible as alternative to solution A. In this case, the inverters must be connected as three-phase.
Note: DC bus network of all drives is possible without problems.
