[scottbryce]

I have a 4 year old NL2500 SY 700.

When I run the machine above 1000 RPM, when ever I execute a M05, or the machine decelerates from 2000-100, 3000-500 etc (From High Speed to Slow Speed, or from medium Speed to stop (M05)) the machine shuts down with 067 Phase Interruption Error.

Alarm Parameter Book suggests alarm 067 is:

An open-phase condition was detected in the input power supply circuit

The machine is sensing some sort of phase/voltage error, but I have has meters on the power supply, cataloguers monitoring the supply and it seems the voltage is NOT being dropped, but the voltage is BEING INCREASED when the spindle is being braked/decellerated.

The fault occurs less when I have MORE machines working in my shop.

It seems that with NO other machines, the fault occurs every minute or so, but with a lot more machines running, lights on, more current being pulled, the voltage does not spike as high during deceleration.

I am completely at a loss, had the machine for 4 weeks now and I have not been able to make a single component.

This error comes up EVERY time I run the machine

Any suggestions?

[fordav11]

if you need it fixed fast I suggest get Fanuc or Mori out to have a look.
if you enable your PM function in the settings I can give you more info.....

[underthetire]

Mitsubishi...
Do you have a transformer on the machine and what is the exact voltage on the machine breaker.

[CPInc]

I had a similar situation with my NLX 2500 SY. The increase in voltage your seeing is normal as the machine pushes current back into the incoming line on Spindle deceleration rather then dumping into a regen resistor bank. My Mori would usually quit with that alarm when multiple Axis's were moving and the spindle was ramping up. After a month or so of service calls from Mitsubishi as well as Mori the problem turned out to be my incoming power was configured as an "Open Delta". What this means is there were only 2 transformers up in the pole rather than 3. Somehow they can tap the 2 transformers to create a third leg. If you have the means to put a scope on your incoming power you can check it. The normal sine wave will have a nice curvature were as the "created" phase will look like a saw tooth on the scope. Once I contacted Com Ed to hang a third transformer and "close" the Delta machine ran fine. Hope this helps !

[underthetire]

This is exactly what I was thinking, too high or unbalanced impedance causing regen problems. That's why it does it less when the other machines are running, somewhere for the regen to go.

[CPInc]

This was very difficult problem for us to diagnose, lots of finger pointing going on in both directions. The way I finally put it to rest was buy renting a 70 kva diesel generator and wiring the machine directly to that and it ran fine. It got Mori and Mits off the hook, but at least We had a path forward. I think the newer controls are getting more sensitive to power issues. My machine sat for almost 3- 1/2 months before the power company was able to updated the service.

[scottbryce]

We have the correct transformer, running on the correct voltage tappings, voltage before and after transformer has been checked and logged with cataloguers. Error is caused when the M05 causes voltage spike in our power supply.

- - - Updated - - -

Thanks for your reply... much appreciated

[scottbryce]

This was very difficult problem for us to diagnose, lots of finger pointing going on in both directions. The way I finally put it to rest was buy renting a 70 kva diesel generator and wiring the machine directly to that and it ran fine. It got Mori and Mits off the hook, but at least We had a path forward. I think the newer controls are getting more sensitive to power issues. My machine sat for almost 3- 1/2 months before the power company was able to updated the service.

I was going to get a generator on site for a week to confirm the same thing.....

[scottbryce]

Thanks to everyone that replied - much appreciated. We ended up getting the MORI technician on site and he applied some SPINDLE CUSHIONING to spindle 1. This simply delayed the ramping up and down of the spindle and reduced the massive current consumption and regenerative power spikes. Definitely some sort of issue with impedance (We have a 120 Metre Cable between out building and the street power. I think the voltage spike is NOT being absorbed by the local power supply grid, due to my long cable run???)

[underthetire]

Or, your transformer is just a high impedance transformer. But yes, its an impedance problem somewhere.

[CPInc]

If it's an open delta service there is no where for the third phase to go during regen, In my case Com Ed was creating three phase with just two phases from the grid. Voltages checked fine on the primary and secondary with the issue, was running a full isolation transformer to convert 240 Delta to 208 Y. Wound up cooking the transformer in my shop before the problem was resolved. I hope your problem is fixed ! Good Luck