Don't bother measuring from each leg to ground. Measure from leg-to-leg. The big 3-phase transformer with jumper bars can be set so that the 3-phase AC voltage at terminals "A", "1" and "2" on the back of your X and Z servo drives are at the correct voltage for the motors. A model 0 motor gets 60vac, a model 5 motor gets 90vac, and the model 10 motor gets 120vac. You can see the model number on the motor tag. Usually, a 0 or 5 motor is used for the X axis and a 10 or 20 motor is used for the Z.

Once the 3-phase to the back of the servos is correct, you may have to adjust a single-phase transformer near the CNC's power supply so that the secondaries show 100vac and 200vac.

If you have a high or low phase, you can adjust for it using potentiometers on the servo boards, but that's usually done along with a full servo tune-up. If the input voltages are within 10% or so, your servos should run OK without blowing any fuses.

Have a look to see what kind of spindle drive you have also. Some of them run right off the mains, and if your shop voltage is too high, you may need a transformer to make it happy. Some machines came with adjustable transformers on the spindle drives also, but not all.