Thank you, maver1ck!

This machine tripped the breaker in the distribution, so it got a total blackout.
Made me think the breaker was faulty, not handling the inrush when powering the drives. After changing it with a new one, it still tripped - 63 amp C characteristic!

Pushed table off the lower Y-axis limit switch, and voilá.

Edit: No! Blackout at powerup again this evening.

Thinking the M20 contactor might be arcing and will change that asap.