Haas Mill turns itself off mid cut

Never ever had this problem before, my 2000 VFOE turned off mid cut 3 time today, no alarm just off, dead, turns back on, runs for 10 min then off again. ??

Contactor?

Look in the alarm history at the time the machine was turned off. Look for any alarms that may have registered prior to shutting off.

Double check the lugs for the main power at the machine (circuit breaker off of course). Make sure no electrical connections are loose.

No alarm history except 903, machine powered up. Does the contactor hold its own power or is there a relay holding it on?

I tightened up all the power lugs, one out of the transformer gave a good half turn, hope that was it. Wasn't.

Talked with my local HFO, they seem to think it is the low volt power supply, dropping out the relay that holds the coil of the contactor.

My K1 contactor had a noticeable buzz to it, compared it to the one in my SL20 lathe, that has no vibration.

Looking at the machine, seems like there is a small microswitch next to K1 that holds it closed, not sure about the "low volt power supply, relay", unless it was triggering the auto power off.

I have also been having a spindle drive fault, and z axis fault, where if the machine has been sitting idle, and it just faults out, and the head drops a couple of inches, that can be scary if you are setting the machine up when it does it. Hasn't faulted like this in operation though.

Anyhow I cable tied the micro switch shut next to K1, probably not a great idea, now I have no power off, but I did try it, pushed power off and it did the spindle fault alarm z axis...
... and it still dropped out, but I was able to observe the PHASE DETECT FAIL light go on a few times.

Since you said you have a SL20 in the shop, borrow some of the parts that are similar, such as the contactor, for troubleshooting. That can speed up the troubleshooting process tremendously.

Even if you have to stop production on the lathe for a short while, it is time well spent and you will have definitive answers if a component is good or bad.

Hope you track it down soon.

I replaced the contactor, was the problem, had to be from the symptoms.

KenFoulks said:

If the K1 contactor is pulling out, it may be a bad contactor, a bad main circuit breaker, or a loose lug at the contactor or main breaker.

Click to expand...

Pretty much spot on, traced it back to a bad electrical sub panel.