Spindle motor overload, DX 32 control

[Gncc50]

I have a 97 EZ pathS lathe I am running it off of a 15hp phase converter. The lathe runs fine until I turn the coolant pump on. Sometimes it will run 25 to 30 minutes and then I get a spindle overload fault. This kills everything. If I then hit the E-Stop. the coolant pump turns on but the lathe won't run until I reset the relay in the panel??? I have pulled the coolant pump and checked it to insure that it turns freely and I have taken it to a motor shop and they checked it and say that it is fine. Any help would be apreciated. I am currently using a 110 pump wired up seperately from the rest of the machine. I have run the machine at fairly heavy loads for extended periods of time with no problems. Thanks

[machintek]

Do you have a current clamp meter? I would check the current consumption of the flood pump, and see if there is a difference phase to phase as well. And not out of the coolant. The coolant will reduce the RPM and thus the counter EMF which raises the current draw. It might be at the edge of what is acceptable. How "rich" is your coolant?
The motor overload is wired into the Emergency stop circuit which is why the whole machine stops.

George

[Gncc50]

I will try as you suggest. The pump does sound like it is laboring but there is brand new coolant in it and I had the pump checked out. I will check the current draw on all three legs and let you know. Thanks very much. The people on this forum are lucky to have someone as knowledgeable as yourself giving them the advice they can't get any where else. Thanks again, Pete