Alarm occurs at power-up it is "438 3 axis inv abnormal current"

If you power-off the machine and power-on 3 or 4 times error dissapears. Any help?

Thanks!
Alan

Does this only happen in the morning when the machine is cold?
Try disconnecting the motor leads from the drive with the power off and take a meter and test the resistance of each leg to ground. If your meter should read infinite, if it doesn't it could be the cable or motor.

3rd Axis on this machine is the turret and it is a servo drive/motor. This drive should not even alarm on power up nor be active I believe. Next time the alarm happens the first time look at the drive and see what the alarm number is and see if it comes on just turning on the main breaker of the machine without the control. If it does its the drive.

If this is not the case power down the machine disconnect the leads from the motor on the 3rd axis and see if the same alarm comes up on the drive. If it does its internal in the drive and the drive needs to be replaced.

Excellent. Thanks for the information. I was not sure why it would show 3 axis as its not a live tool lathe. Occasionally it shows up as x axis as well. If you shut the lathe off after running parts for a few hours and turn it back on the error does not occur.

Its a 98' that we bought new and unfortunatley our service center has gone out of business a few years ago. (when mori decided to do all their own service work) and our nearest is not very responsive.

How would i tell if it throws an alarm with the control panel off?

I will do some diagnostic in the morning.

Thanks!
Alan

Turn on only the back breaker and check the drive alarms. One of the drives I think has two axis on it. It could be the X and 3rd. So that may also be common between the two alarms.

Forgive me for being unknowledged, we havent had to trouble shoot this guy much. How do you acess the cabinet with the breaker on? The door limit switches make it so when you open the cabinet the power is cut.

This morning i turned on the main breaker and then gave the lathe a few minuted before turning on the front panel and there were no errors.

Thanks,
Alan

I think we figured it out. Upon inspection in the back of the power cabinet 3 of the main leads were arcing inside the heat shrink. We removed them from the breaker/power distribution block and one end fell off. It appears as though they didnt have enough wire through the end before they terminated it.

I turned the machine on and no errors occurred. We will see in the morning if we are good to go.





Thanks!
Alan

Got to love the smell of burnt wire & rubber!!

If you need to open the door with the power on. There is a small screw that can be turned to unlatch the door from the breaker. There is also a key switch in the cabinet door that should be turned to the right position as well.

It tripped out again this morning

The X/Turret Drive Board shows the error "b" or "6"

Do you know what that references?

Is that a 16 or 16I series control?
b or 6 points to Drive for both controls though it says to make sure you check for shorts in the motor phases to ground as well as shorts between phases. Make sure you disconnect the wires from the drive to test. I think you are looking at a bad drive myself. The turret motor should not even be coming on at all therefore a short shouldn't even matter on power up. The trick is to check the alarms on the drive before you power it on the front of the control. If you see the b or 6 powering on the breaker then it is definitely in the drive.

Its a Fanuc 21i

We did check the drive before the front panel was turned on. Thats when the error was showing. I will test for shorts this afternoon. I noticed there is a "battery" pull out on the drive. Could that be what the "b" error could stand for and be causing all the problems??

Thanks
Alan

Replace the drive

Sounds good.

Do you have a good source to purchase parts from?

Take your pick. I prefer Fanuc, because I want to make sure I get something that is going to be tested well when repaired or purchase new. My travel to the customer and labor has to be billed to them and its a waisted day production which they can not afford, so it makes more sense for myself. But there are many others like fanucworld and many online drive repair parts places as well that have parts if you are looking to take chances with them or try to have your drive repaired. But thats your call. With intermittent alarms that go away currently its probably not worth the risk to repair yours. Unless you wait till it does not run at all and gets worse, which the repair shop might be able to find something easier.

If the drive shows a "b" before you turn on the control then the problem is the servodrive. Is the number A06B-6096-H206 or H208?
Next time you power on the control with no alarms on it try to ask for tool #1 and mark the turret because when you replace the servodrive you will loose its reference point!

It is an A06B-6096-H206

New would be the way to go. 11 years of dedicated service and this is the first failure, shes earned it.