I did a high speed tanning bed many years ago, it was the first one in the states, and they sent the German engineer with it to start it up. The facility was 120/208, but he needed 240 volts. I used open delta buck boost transformers to get it to 240. I asked him if it used a neutral, he said no. But as I was looking at the wiring diagram, something caught my eye. The manufacturer was using the ground as a neutral for the 120 volt controls! I made sure the unboosted leg was on the line that feed the controls.