sa -- Short of complete replacement, there is no practical way to convert the two-transformer configuration described into a 4-wire wye system, and very little would likley be gained by doing so. Is this a new installation, or has it been in normal/acceptable service for a time?
Can you respond with the actual motor-nameplate voltage, rated full-load current, horsepower and service factor? (Are you confident that the field-tested operating voltage and current readings are accurate?)
Relog the operating {motor-running} voltages at L1-L2, L2-L3 and L3-L1, neglecting any “to-ground” readings, and taken at the load-side connections of the starter. Then, record L1, L2, and L3 currents.
The reported currents are wildly unbalanced, and if accurate, indicate a severely crippled motor with very little ability to deliver mechanical horsepower to its shaft. Extreme overheating of the stator windings and consequent near-term failure should be expected.
There is limited online information available for submersible water-pump motors, but I don’t think it will help much.
http://www.franklin-electric.com/Manual/contents.html and
http://www.franklin-electric.com/Manual/pdf/Install_Check_List.pdf Another listing of typical service-transformer/voltage relationships is http://home.att.net/~benmiller/elecsys.htm
