Power trip off when coolant pump starts

Problem:  The CNC machine power trip off when the CNC program runs the coolant pump starts under Auto mode of the CNC controller.

Check if the problem is same as described by the user: checked and found out the CNC machine power trips off when the coolant pump starts, either by manual or Auto modes, if it is not started, everything is fine. (from http://www.CNCmakers.com)

Diagnose: There could be several reasons:

1-      Check the coolant pump has problem or not?

2-      Any wrong connection or short circuits?

3-      The contactor and the segment switch lost phase or not? For this reason, we could use universal meter to check if there is any open circuit or short circuit when the coolant pump is off, if all is fine, we need to uninstall the coolant pump motor, and check it if there is any unusual voltages.

In this case we found the resistance value between motor coil and the CNC machine is too small, after changed the motor the CNC machine resume to work.