Yellow cap servo ...might be dead??

[MwTech Inc]

Fanuc A06B-0651-b011 10m On a Koma rotary table made in 89

I get the 403 alarm and hcal on the drive.

Went thru all cables plugs , pulled servo apart, super clean, it can't have been used much at all. There was no trace of carbon, one q tip didn't even get dirty
wiping out brush holders.

Commutator looks new.......

Status right now.........machine will power up, no alarms.. X<Y<Z all home. A will not.

Diagnostic 35 does show a interlock issue but thats another battle....

Using Command I can unclamp brake, give it a G28 A120.( i did 120 cause I had manually rotated the thing to 0) input and the servo will start a move and in a 1/2 sec trip the drive and show Hcal./403

However if I pull the motor power cable off the servo case, no hcal alarn just tgls which is normal.....

With the condition of the servo I have trouble thinking its bad??

I don't have a megger to do the lines etc so maybe its possible still a wiring issue??

And what is the difference between a B011 and B012 other than 2000 m vs 2500M on the label??

This is the last thing on this ol girl I haven't been able to fix...yet.
Any input would be appreciated

Let me add something......someone spliced the 4 power wires in the cabinet with butt connectors, really????

Anyway i did make the proper soldered connections, wonder if they mixed up the lines???

I have a 6m connection book and the wiring is in there, but i'll need help to trace wires tomorrow.

 

[Vancbiker]

Sure sounds like crossed up wiring.

 

[MwTech Inc]

Well.........

New status:

Verified all wiring from table to machine...all was OK

On startup everything comes on and the 4th just sits there UNTIL you just touch the gear on the servo( i have the gear case cover off)

the second you touch the gear its shuts down and gives 430/hcal.

So....finally took the pulse coder off the servo, brought the machine back up , did a quick m69 to take the brake off and ,the servo starts to run

Keeps right on going, table going round. so obviously no problem with the motor...

BUT soon as you lightly shake or just barely touch the encoder shaft, BAM, 403/hcal.

Now I found the encoder loose under the cap and i had taken the servo motor off the table, previous repair attempt, and had set it on the floor, wasn't until i picked
it back up heard a rattle and found it.

So its hard t to say how much banging around went on before me..

And while the table was running I checked diagnostics and I had my (1) in place on bit 4

So am i to assume a bad coder???

 

[Vancbiker]

Unless you have an oscilloscope to test the encoder your best bet is to swap it out.

 

[Garwood]

My money would be on someone needed an encoder for X, Y or Z and stole it from the 4th to keep a machine running. They loosely re-assembled it knowing they'd need to fix it next time they needed the 4th.

If you need a working encoder message me the numbers and I'll see if I have a spare.

 

[MwTech Inc]

Nobody ever comes back and relates the solution.........

Turns out it was the velocity drive...I can only assume when the motor power wires were cut for whatever reason they mis-wired and messed up the drive.

So now my 38 year old Hitachi Seiki is fully 100% functional

Thanks to all that answered questions.