I have attached photos of connection block for spindle drive as well as pics of serial numbers on drive cards.

in case you can not make out terminal connections

X421

          connection at 56 and 14

X431

          2 connections at 663

          connection at 81

          looks like a jumper between 81 and 65

          connection at 9

X451

         connection at A92

X441

        connection at 672 and 673

When the machine alarms out with a “spindle motor overload”  It is very orderly.

All travel stops coolant cycles off and spindle brakes to zero rpm.  Spindle can be under small to zero load when this occurs.

must wait one minute before you are able to restart servos. simodrive shows green left center and yellow right center lights, green goes off when servo restarts

Ran all day today.  first 10 mins it had a spindle motor overload alarm.

since than it has run 7 hours alarm free.  milling, drill, and even rigid tapping with no issue

spindle ramps right up to 6000rpm no issue

I have not replaced capacitors in phase convertor so power is still not within 10%

Ran for a couple more hours with no issues.

started a new part and alarmed out with spindle motor overload 2 times in the program.

ran again and alarmed out at the same point in program as last part.  had just done a rapid move away from part and next line was m09 (coolant off)