SH-630 flashing EMG with HOT door interlock coils

Hello everybody,

I'm gonna make a long story short here and save you guys some reading. We had a servo amp death festival over about the last month this poor machine had it's amps borrowed to get others running. It now has 3 new amps in it. When I fired it back up I was greeted with a flashing EMG light, no emergency buttons are pushed anywhere so that is not the issue. The other part of this that I am finding interesting is the coil on the door interlock is getting quite warm, it will not lock the interlock you can shut the door and it bounces right back out. I am hoping you guys might be able to point me in a direction here. I suspect the constant on interlock has got to play into the flashing EMG light. I am not able to move any of the axis either right now it's just a great big anchor. Any help you guys can give me would be so very greatly appreciated!

Take the cover off the interlock and check the wiring. Maybe it's full of coolant. Or maybe it just needs replacing. Try bypassing it for the time being and see if that clears the alarm.

Also when was the last time you checked the main voltage at the machine? I don't know... frying a bunch of amps says something.

So we have checked the interlock, as well as tried putting in a new one. Upon further inspection it appears what we having going on is the contactor that should be disengaging the interlock is not getting power, this particular contactor is also provided power via the emergency circuit. I have been trying to chase down the fault in the emergency circuit but there are so many branches in the emergency circuit it's proving to be quite difficult to find. I am getting power everywhere else in the machine it's just the KA1 and KA2 that I need power to which comes from the contactor. I am sure it's some simple thing I am overlooking but it's been a challenge thus far to say the least to track it down.

For the most part an E-Stop circuit is one giant series circuit. Like a very old string of Christmas Tree lights where if one goes out they all do. On Mori machines there are actually two running side by side in a redundant circuit. Labeled with pairs of even number and odd number wires. These can be checked with power off and a Ohm Meter. Meaning stick one probe on the lowest numbered connection and work your way up. Not sure how E-Stop interconnects with the Interlocks through the safety relays. Those big blank boxes with green LEDS have always confused me a little.

I hope you have an electrical manual as tracing these down will be a lot easier. Can't imagine having a big complicated Horizontal without all the books.


One last thing... if you have a chip conveyor or anything that used to be connected that included an E-Stop button on it, and it is not connected now, that will through an alarm, because that now represents a break in the Christmas Tree lights if you will. If you have something like that you no longer use you have to put a jumper across the connections on the proper terminal rail. Again where the Electrical Manual will be a giant help.

Well I am chasing the stop circuit down a bit of a different path, it appears the particular branch of stop that is related to KA1 KA2 which is where I need power is very related to limit switches and over travel as it would happen just before all this fun happened I got an X+ overtravel alarm. I was trying to sport the limit switch bit I am not able to however my X is quite a bit higher than I think it should be. Thank you guys very much for your advice I do greatly appreciate it. I spent quite a bit of time last night tracing through wiring diagrams which is helpful I am not completely in the dark now. I will say I am used to automotive diagrams these took a bit of getting used to however once I got my brain wrapped around how to read them they are really a far superior diagram setup. Anyway off I go to manually lower X and hope and pray that is the problem. Fingers crossed!!!!!!!

It was in fact an overtravel, got my X back within and almost everything cleared up. Now with new amps I have to re-zero my axis, typically a pretty easy procedure however upon inspecting this machine I don't have any reference points within the machine. I am not sure how to find zero without having reference points, also for some reason on my keypad the only number I can get to work is 8 sometimes 9 depending on what screen I am in. Letters work just fine, I was able to get everything to work yesterday through a series of steps but I cannot for the life of me remember what I did anybody have any thoughts?

I have a 97-98 Mori VMC. The home positions are when the ball nut of the ball screw is 5mm off the end of the ball screw bumpers at each end of the screw. If you look close in your parts manual on the ball screw pages you'll see that they reference that concept there. I think Mori has used those yellow/orange bumpers for awhile. Here is how I did my machine after I rebuilt it.

Find out what the axis travel book specs are for your machine in MM. (Will be on the same ball screw parts book page) Turn on your control and put it in MM mode. I went to an art store and bought a plastic metric ruler. My Y axis travel is 510mm. I cut the ruler off at 515mm. I then opened the front way cover, moved the table back until I could perfectly fit that ruler between the end of the ball nut and the plastic bumper on the end of the ball screw. I then put a dial indicator in a fixed position against something on the machine that could reference Y travel. That is the position you need to be in when you flip the parameter 1815 from 0 to 1 or back again. (FANUC 10-21) I don't remember the specifics but sounds like you do. (See link below) All I remember is you need that dial indicator because the machine moves a little when you turn it off. And you'll need to be able to put it back exactly, as the position numbers on the display won't mean anything realistic until referenced.

In the parameters there is also a soft limit set 1mm beyond machine travels, 1mm and -511mm in my case. Set in Least Input Increment. (Parameters 1320/1000 //1321/- 511000) Look at your Stored Stroke Check Limits in the Neg and Pos direction. (Parameters 1300-1321) My X axis is 800mm. I used my same ruler and did the math to get that one. The Z axis is set according to the needs of the tool changer. You being on a horizontal I'm sure you know those axis will be rotated around from what you find on a VMC.

BTW - the soft over travel thing above is for machines set without trip dogs. Meaning your servos have absolute encoders and battery backup so you don't have to normally home the machine after turning it on.

There may be other ways to do this but that's how I regained my home positions after a ground up rebuild with new rails and screws all around. After that I then lined up the home arrows that are normally on the machine. Sound like yours are missing or worn off. They're not very accurate anyway.


Here is a link to Zero Return Setting for all controls. Great website.

Zero return procedure and gridshift parameter setting on Fanuc CNC controls


Below moved here from above.

After that you set your physical hard over travel stops against the dogs when the machine is in the soft over travel position. You should be able to watch a bit flip on a screen when doing this. Or check continuity on the wires from the limit switch if you don't want to be crawling around in the machine with it on. (Bit flipping screen might still work in E-Stop) Although the need for setting the hard over-travels might be slim, as they should still be good from previously unless one got bent out of position.

Hi!!!
I have a similar problem with a Nakamura Tome TMC-12 Control Series 21-T, this machine was working well, until a technician came to check a vibration in the Z axis servo, apparently it loaded parameters and the machine did not return to work, I have a backup of the machine parameters, I reloaded them, no alarm comes out, but it is in EMG state, I can navigate the menus, but nothing else works (spindle, hydraulic system, turret , move the axes).
Hopefully someone can help me, best regards.