3 phase converter and odd behavior on CNC mill

A friend of mine recently wanted to show me a part cutting on his CNC
mill (a BPort) that he had running with a phase converter. The
machine was behaving very badly when I showed up, however. He said
that it was running earlier in the day, but when I popped the back to
look at the voltages I got the following (when referenced to ground):
120V, 60V, 60V. This seems *very* wrong to me as I would have
expected at least two 120V legs (the two from the Power company).
Anyhow, I am planning to look at the thing before he blows up the
CNC. My question is pretty simple. The converter is a Cedarburg and
it has a bunch of wires coming out of it; a "bunch" because I don't
know if it is a Wye or Delta wound motor. What is the best way of
determining if a coil is burned out.... and I don't have a megger.

Thanks.