View Full Version : Why does my mill cut out electrically after a period of use

25-08-2021, 07:52 PM
New owner of Bridgeport Milling Machine. Doing a light mill in wood using power feed - all well for several minutes, then an electrical cut out occurs with a slight click (seems to be in the wiring box).

Worklight remains on, but "on" switch (a green switch on a fitting attached low right on the machine, next to a red off switch, and not the main on/off control top left by the motor) no longer functions.

After a period, and after opening an reclosing the wiring box - (although I could find no trip switch that had tripped in there) , including turning the plastic yellow isolating boss switch on the exterior of the wiring box, it functions again.

Then same thing repeats.

I don't understand why it trips (am I making too heavy a cut , in too low a spindle speed - seemed to me unlikely as I am only milling wood).

And I don't understand what I did to reset it, apart from open and close the wiring box and generally fiddle about with the exterior isolating switch.

It actually seemed to reset itself after some days idle with me scratching my head and looking at youtube videos and the manual.
Thank you for any advice.

26-08-2021, 01:11 AM
If your on/off switch is an NVR switch, it could have burnt contacts, or possibly you have an interlock switch fault. These are just general ideas of things to look at. I have no specific knowledge of Bridgeport machines.

26-08-2021, 09:32 AM
Thankyou Cropwell. I switched to full spindle speed and seem to be back in action, but still puzzled and will be keeping an eye on this.

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