I have a Bridgeport Seried 2 Interact4 that is powered by a 10 horsepower phase converter. I can't start the spindle with more than 300 RPM or the machine will reset. I think the large spindle motor is drawing so much current at startup the control electronics looses voltage momentarily and resets. When the spindle is commanded to start it hits really hard ( a very short ramp up to speed if any ramp at all.) Is there a parameter that can be set to increase ramp time of the spindle so it doesn't require so much current to get it up to speed?

Presently, I have to get to milling speed in steps. (Start the spindle at 200 then increas to 350 then 550 and so on.)

There are two different spindle drives that were used with this machine. A Contraves and a KTK (newer). I believe that both are 3 phase devices. If they were not, you could run the two good legs to these drives. None of these have a parameter list resident in the drive or control that is accessible. The control says go to such a speed and they comply. There are pots (adjustable potentiometers) on these spindle drives. If you have the book, it may be possible to decrease the ramp angle for accel and decel that way. Too much and the control will time out (parameter change).
You may want to check the brushes on the spindle motor while you are playing with the machine. They do have a tendency to wear out. Make sure the phasing is such that the spindle motor cooling fan is not working against the natural chimney effect.

George