First thing is to actually measure all three legs and see what you've got. Often times if you cherry pick the best pair you can get closer to 220. Also you can see if you have a wild leg, as they typically run a little higher. Also check the MPOE for what kind of service comes into the building, especially if it is a multi unit building. Older buildings often have more than one feed, and can have separate single and three phase feeds. Depending on what is run from the street, you can often get the power company to change your service for little to no cost. Sometimes it's as easy for them as moving a wire to a different transformer tap on the pole. Do you have any three phase loads, or just single phase? The lower the input voltage, the higher the current required for the same power, so it's easier on most machines to run the highest rated voltage if possible.
Long arc, short arc, heliarc and in-the-dark!