Need Help!- VRDY OFF Alarm

[NID]

My old Wasino LG-81 CNC lathe w/ Fanuc 3T controller. It started giving me a servo alarm today. Code is #02 which says VRDY OFF, Velocity Control Unit has Turned Off.

This seems to happen when in Rapid and doing a type of peck drilling action in the Z axis. I switched the Rapid setting to 25% and am getting by but it has slowed up my cycle times considerably.

BTW, I have only been able to run the Rapid at 50% for years because of a similar alarm once in a while if I try and run at 100%. I suppose this means something is wearing out.

Any advice or insights will be much appreciated.

[fanuservicetech]

How do you usually reset this alarm? i.e. by just pressing "reset" key on the keyboard? by turning power off/on? What is the servo unit number A06B-60xx-Hxxx? servo motors are yellow cap or black cap?

[NID]

Thanks for the reply.
The only way to reset is to power the entire machine off.
The only other info I have is what is displayed on the screen "Servo Alarm 02 (VRDY OFF)"
How do I find the Servo unit Number you refer to?

[greenery_fr]

Originally Posted by NID Thanks for the reply. The only way to reset is to power the entire machine off. The only other info I have is what is displayed on the screen "Servo Alarm 02 (VRDY OFF)" How do I find the Servo unit Number you refer to?

Hi

Check your led alarm in your servo driver, you will see an alarm on servo driver

[fanuservicetech]

Here's what a typical Fanuc DC servo unit looks like.
Like "greenery fr" said, you should check if any red LEDs are on when you have this alarm BEFORE you reset it next time.

[NID]

Ok, Got the alarm again.
Found a red LED alarm light labeled "TGLS L"

Wondering what kind of problem this is.
Thanks much

[fanuservicetech]

TGLS stands for Tacho-generator(the feedback on the motor)loss alarm. "L" is for the first axis (usually x axis). Looks like you've got a dual axis drive (i.e. both motors are driven by one servo unit). You may have dirty/worn out brushes on the tacho-generator on your x axis motor.

[NID]

Thank you for the helpful reply.
It does appear that I have a dual axis drive. Of the two Honda plugs at the bottom, X is on the left and Z is on the right.

I have confirmed that the alarm is happening in the Z axis. I can now get it to happen in the Jog Feed mode with the joy stick. I checked the bruches on the servo motor and also checked every phillips screw connection on just about everything.
Also checked the screw itself to see if there was any chips imbedded in it and it seems good.

Very much appreciating your input...

[NID]

Just got the same alarm while doing a zero return in the X axis and it won't clear even after powering off/on.
I'm dead in the water!
HELP!!

[CNCZILLA]

You will have to start a process of elimination. I can tell you that typicaly it is almost always the drive or motor. I assume this machine only has one X and Z or is it a 4 axis machine. If so then simply swap the drives and see if the problem moves. If you do not have another drive or another machine with a drive like it that you can swap then call the guys at Fanuc. Does the problem seem to be intermitten or does it happen every time you move the axis. Because you can operate the machine at a lower rapid setting then it probably is the drive. you can also swap the motor with another one if you have that luxury. However since it is happening in both axes then you probably dont have 2 bad motors or tachs at the same time, this might not be impossible but it is highly unlikely. You probably have a bad drive.

[NID]

This is a 2 axis machine and now the alarm won't clear even when I power the machine off the then on. I'm inclined to think it's the drive. Especially since I got an alarm in both Z and X axis right before it got to its current state of not resetting.

I don't have any spare drives or motors to switch to for testing purposes. I think it must be the dual axis drive but I'll give Fanuc a call in the morning to see if they can walk me through a way to confirm this.

Thanks

[CNCZILLA]

Check your incoming voltage from the power supply. If that voltage isn't correct then the drives may not be generating the proper buss voltage which can generate a VRDY alarm. You can also check this, it should be 300v and this will be on the buss bars connecting the drives.