Hi Forum, was just dry running to check another problem when the spindle stopped on encoder disconnection, a problem I have had before on another machine from a hot spindle motor. Could barely hold my hand on the casing which was strange at 3 - 4% loading. Removed the red plastic fan cover and found the 3 phase Minebea fan rotating as shown in the little drawing in the link below, CCW with vanes rotating inwards.

6925RT Series (Steel impeller?Standard type) | AC fan motors for industrial use | Product Category | eMinebea

Reversed direction so that cooling air blew upwards for normal running temperature on the casing. Any ideas thanks on what is correct? regards.