This rule will make virtually every 280/240 rated machine I worked on illegal. When we retapped a machine for wye(208) or delta(240) all it changed was the input windings on the DC power supplies. The motors stayed the same.
It would be interesting to see what the current draw difference or the heat buildup difference really was.
All of our big machines generally got connected to 3p wye but red leg delta was an option.


Greg Fretwell