What is reason you have 208 volts but yet need a phase converter?Sorry for the confusion...I will start again from what I remember
Single phase 208 to a rotary converter output of converter 120/240 3 phase no neutral with high leg. If I need a neutral can I get it from the 208v panel feeding the converter?
Finding a way to get third phase from the (likely three phase) source is a wiser investment of time and money over using the phase converter. JMO.
Otherwise assuming there is a neutral at your source - then yes.