Albania and Norway has still lots of 230V 3-phase supply without a common Neutral wire. Here in Norway all new systems are 400/230V V with N. I believe that UK stopped useng such systems in 1948, so we are a litt bit after
At job we have one old, and one new building, one with 3 phase 230V supply, and one with 400/230V .
A little off thread, but when i designed a machine for the Oakland- San Francisco (bay) bridge, I learned that the motor designed for 400V 50hz worked well on 480V 60 Hz and became 20% "stronger".
