Help with Kollmorgen Servo star

[Neale]

As m_c points out, you do have to consider the between-phase/phase-to-neutral voltages. That might be what is implied by the 3-phase transformer. I use the common Huanyang inverter for my router spindle and like everyone else, I just use 2 of the 3 input terminals for single-phase input. I also have a nominal 5HP/3KW inverter (by ABB) for my lathe which uses a 3HP 3-phase motor. I run that off single-phase input but the problem is that, in effect, it derates itself. The way these inverters generally work is by rectifying and smoothing the input voltage to DC and then chopping that to produce variable-frequency output pseudo-AC. At higher loads, you start to get more ripple on the DC which is worse if it is only getting topped up once per cycle (single phase) rather than three times per cycle (three-phase). My inverter trips out above a certain load as a result, although fortunately above spindle speeds that I normally use.