A CNC can run on a rotary or digital phase converter when its maker allows one and the converter keeps the three legs balanced. Here's how to check your CNC maker's rules, pick a type and size it by each converter maker's published rule.
To choose a digital phase converter, check which design "digital" means, then size it from your machine's nameplate. See the hp and amp rule, a worked example, balance for CNC, and what to ask the maker before you buy.
A machine with its own VFD, such as a CNC mill or lathe, can often run on a rotary phase converter if the machine's maker allows it. See what to check first: voltage balance, converter size, the manufactured leg and regen braking.
