Need Help!- fanuc servo drive diagnostics

[EPS]

I have a 6m control with a 403 servo error. I don't want to have to start buying drives until I can say which on is faulty or if it's a drive at all.

Does anyone know a technique for narrowing down the problem to one specific drive

I have two A06B-6047-H001's and two A20B-0006-XXXX drives. The problem was intermittant with 400, 401, 403 errors but now stays on 403 and I can't clear it by powering down. On power up the contactor for the drives kicks on momentarily then right back off. There are no error lights on that I can see.

The machine runs on a rotary phase converter but my voltage measures a little high 113 volts on the drives instead of 100 and 27dc on the boards instead of 24v.

Any thoughts on swapping top boards? could it possibly damage something else? Is there a way to disable one drive and fool the machine into powering up?
I really need this machine running, any help is greatly appreciated.

[Al_The_Man]

Try disconnecting the motor armature leads and see if the fault comes up right away still?
Possible the Z axis. but you may have to try each in turn.
Al.

[Stevie Bramwell]

Hi EPS,

Does your machine have a 4th axis? Have you had a 402 alarm?

400 - The control received the X, Y, or Z axis overload signal.
401 - The READY signal (VRDY) of the X, Y, or Z axis velocity control has turned off.
402 - The control received the 4th axis overload signal.
403 - The READY signal (VRDY) of the 4th axis velocity control has turned off.

You say that there aren't any alarm lights lit OVC or TGLS on the front (top) cards (Overcurrent or Tacho Generator Loss).
There should be a fuse/overload on the power section of the drive (board at the back) that may have blown.
Check the connections to the motor and tacho.

I hope this helps.

Stevie

[EPS]

OK I've tried almost everything I can think and all the suggestions and no change. Still a 403 servo alarm.

heres my list so far;
1 checked all motors, tachs, and encoders (excellent shape)
2 swapped top boards xy
3 swapped whole drives xy
4 swapped whole drives uv
5 checked all voltages

nothing seems to change the 403 alarm I was hoping to at least get it to alarm something else but no luck.

Does anyone know if there is card in the control section that could be responsible? Right now all I can think of is a signal problem because the drives power up then right back off like there not recieving a signal of some sort. or some type of internal e-stop issue.

[GPena]

If motor, encoders and drives are all fine; the next step is checking the wiring. Check at the connectors in both sides for continuity, maybe there is a wire broken.

GP.

[EPS]

continuity between motors and drives/encoders is fine also. I'm not sure about between drives and control though. I don't have any wiring diagrams and trying to chase them through the cabinet seems almost impossible. anyone have diagrams for the 6m?

[GPena]

Yes, between servo and control. It is a 20 pin honda connector. You have 4 axes right? the problem seems to be in the 4th axis, then you must have an additional axes card and the connector must go there.

Please check.

GP.

[Woody111]

Also check your cables to ground make sure you disconnect from your drives leaving them connected to the motors. If you get a reading to ground disconnect the motor and check again if it is there bad cable if not bad motor.

[zavateandu]

hm interesting problem
if u have no succes ,u have 3 big relays(are contactors) on the servo 1 for each axe and i think 1 of them does not make the contact corect
there is a signal "MCON" from the NC that must be low.
u have on the board some leds LV1,LV2,LV3?
i think LV2 is red on your board.

i had this once and i replaced 1 big relay with a normal contactor.
it exact down on the servo.
are black with blue and u see some contacts normal open and normal closed drwawed on them.

check if the contacts are corect.
the problem ia m 100% sure is from the contactors.

have a nice day

[cncserveng]

If it is a 4th axis problem, you may be able to unplug it and turn off the axis externally just to prove a point. Check your machine user manual.

(403 is 4th axis VRDY error)