Spindle rpm fluctuating and causing 1008 Spindle Drive Fault

[youngguns3]

Hi,

It's getting better as I learn this machine. It seemed to be running fine when I tried out a program that was already loaded, but now the spindle rpm is fluctuating, and then causing random 1008 Spindle Drive Fault errors.

The spindle will slow down and speed up noticeably, and I noticed the voltage also fluctuates from 97 to 108 volts on the outgoing three wires (checking two at a time with my meter) as it is acting up. It has 215 volt three phase going in. The drive also makes a buzzing noise. It did that some before, and then when the Cyclone was running ok, there was no buzzing. Also, the wires heat up considerably when it is running now.

Could this be a motor problem or a drive problem? I can turn the spindle fairly easily by hand when the machine is off, so I don't think that is an issue.

I can't tell you all enough how much I appreciate the help you have been giving me. This is my first Fanuc controller (I have worked a bit with Centroid before), and I have learned things that would have otherwise taken a very long time.

Bill Gillen

[Denford Admin]

I'd just double check the transformer tappings for the input voltage.
especially the spindle drive transformer tappings for 215 (if there is one??)

Where does the 215 come from ? is it 240V single phase to 3 phase inverter ?

[youngguns3]

Hi,

My input voltage checks at 430V 3-phase, and the out voltage from the transformer is 215V 3-phase, which I didn't worry about because it is within 10 percent. It seems that just the voltage going out to the spindle drive is what is varying. I was wondering if the Hertz rate supposed to be what changes for the motor, or the voltage? I also was thinking it might be a loose connection at the motor, but didn't want to go into that yet.

I was also wondering how the 1008 Spindle fault is triggered.

Thanks again,

Bill Gillen

[Denford Admin]

I don't know what spindle drive unit is on that machine - the drawings I found are for Fanuc 0TA and it just says "Spindle Drive Unit"

The alarm will be activated from an input that comes from the fault output on the spindle drive.
You need to find the drive type - there's probably a manual for it on here somewhere.
If it uses analogue speed command, then the next easiest thing to rule out is that ie, by supplying a fixed command voltage (0-10vDC) and seeing how the motor runs then

[youngguns3]

Hi,

I checked all the fuses, and they are ok. After analyzing the AC spindle drive faults, I have one bulb lit in the number two spot. The text for this says "Speed deviates from commanded speed". I read the list of alarms page, and the causes include Overload, transistor module is damaged, loose connections, error with speed feedback signal and blown fuse.

A friend of mine who used to work with GE controllers thinks the frequency and voltage from the drive needs to be adjusted, using the pots on the board. I don't have that manual, so I wanted to ask what the hertz and frequency need to be, so I can adjust that using the pots on the board.

Also, is there a good way to check the transistor module? Any suggestions are appreciated.

Thanks,
Bill Gillen

[Martin]

Hi Bill,

Is there a modelnumber on the drive or board number?

[youngguns3]

Hi,

I checked the board, and here is what I saw.

AC SPINDLE SERVO UNIT
Type No. A06B-6052-H001
Mfg. No. P7Y000595


On the boards,
(the one in back) A16B-1100-009?/09D
(the one in front) A16B-1100-0080, Edition 08D

Any information on the spindle drive unit is appreciated.

Thanks again,
Bill Gillen

[Martin]

Is there a alarm number on the drive board?

The alarm is displayed by four binary codes using LEDs mounted on the PCB.

They look to be marked up 8,4,2,1

[youngguns3]

Hi,

I looked at the AC Spindle Drive Faults sheet, and then the machine. Only #2 is lit up when the error occurs. The "Content of Alarms" description states "Speed deviates from commanded speeds" for that error, and the speed does go up and down noticeably in something like a jerky motion.

Thank you again,

Bill Gillen

[Denford Admin]

I looked at the AC Spindle Drive Faults sheet

Would you be able to post this up on here ? Anyone else with the same drive may find the info useful.

My guesses would be:
Encoder wiring is faulty, broken wires or corroded connectors.
Encoder is damaged/loose/dirty
Load is tight (belt/bearings etc...) - does it run ok without the belt fitted?

I'd really have a good inspection of the motor/encoder/wiring and connectors.
Is there a separate spindle encoder to the spindle motor feedback on this system ?
I'm not sure how it worked or whether it would effect the speed, but am sure you could specify whether you had "separate pulse coder" for the spindle, in the Fanuc parameters.

[youngguns3]

I looked at the AC Spindle Drive Faults sheet

Would you be able to post this up on here ? Anyone else with the same drive may find the info useful.

Hi,

I'm glad to make any kind of contribution. Here is the link:

http://www.repair-fanuc.com/AC%20Spindle%20Alarm.htm

I checked the spindle drive, and it appears to have an external encoder. It is driven by a gilmer belt from the spindle.

Thanks again,
Bill Gillen

[edit by Denford Admin] Added external file as a .pdf [/edit]

[Martin]

I have scanned the relavant pages out of the manual regarding alarm number 2.


Hope it helps.

[youngguns3]

Hi,

My alarms sheet, item 2 under "Speed is deviated from the command value" suggests the Transistor module is defective. The Check Procedure says Transistor collector-emitter is open, and the Remedy is Replace Transistor module.

Is there a simple way to test this transistor module? Or is it one of those situations where you "guess, spend the money and go to the next problem"?

I found this transistor module, and wanted to ask; Is this the module they are talking about?

http://www.dnc-electronics.co.uk/fanuc- ... -0209.html


Also, if it is, I think I know where it goes, but wanted to ask. I think it goes behind the double stacked circuit board near the center of the cabinet. Is that correct?

Thank you again,
Bill Gillen

[Denford Admin]

That transistor module looks right. They are usually bolted to the underside of the main power circuit board (which will be underneath the top control board where the Led's and connectors are)