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well new machine died Fanuc 18M Controller, not sure what happened.

BT Fabrication

Stainless
Joined
Nov 3, 2019
yep, Im beginning to wonder that myself. I think I might be looking for a 240V to a 208V transformer to reduce the voltage a bit and possibly regulate it a bit better from spikes.
there is no badge on it, other then one someone made saying it was 230V input.
fanuc website says 200-230V +10%-5%
RPC manufactured 3 phase is most likely my issues and where its stemming from. Just spent a little bit of time rebalancing the legs as found one of the run caps were dead
and I'm guessing the regeneration in the spindle drive might have caused a voltage spike that killed something this time.
finding out this CNC is sensitive on power much more then anything else I have ran on the same circuits.
machine in the previous shop ran off 480V to 208V transformer.
and looking in the power supply, quite a few other parts have been replaced previously before I had got it. Probably due to the massive amount of dirt inside it/all over it.

power supply still seems OK, but thinking it has something inside the spindle amp that has shorted out is my guess.
 

huleo

Hot Rolled
Joined
Feb 12, 2014
Location
UT
How could I have guessed..... YES, your problems are coming from your power supply. You are trying to feed 240V, PLUS very likely poor balance and I have seen 255V on an RPC. At a minimum, you need to find out what the input voltage to your machine is, and run on the bottom end.
 

cnctoolcat

Diamond
Joined
Sep 18, 2006
Location
Abingdon, VA
All the drives, internal electronics, etc. on the typical-Fanuc-controlled machine operates at 200 volts.

If your drives are seeing 250V or more, I would about guarantee that's what is damaging them.

Measure the actual voltage going into the internal power supply and drives, get it as close to 200V as you can.

ToolCat
 

FredC

Titanium
Joined
Oct 29, 2010
Location
Dewees Texas
Second on Ox's comment. I brought up over voltage casing issues in my Hardinge with 18T control. That was at this place with 248 volts on true three phase. Rural area and the electric co-op runs the voltage high on purpose to protect from voltage drop when the neighbors turn on their 500 horse irrigation pumps.
In the old place near town we had no 3 phase, so we ran the same machine off an RPC with no issues. All the pops and failures happened here with the true 3 phase. Our fix was easy move a tap on the internal Hardinge transformer for the 115 volt controls. The rest of the machine that is not on the control transformer is happy with the 248 and sometimes plus voltage.

Additional thought-- The PRC that we ran was CNC rated to hold the voltages closer.
 

huleo

Hot Rolled
Joined
Feb 12, 2014
Location
UT
'Can' the controls survive with higher voltage. Possible. I have done it myself, but it undoubtedly puts more stress on components. All when a simple auto transformer on the 1P side can get down to a safer voltage. They are cheap and easy to install.

Some machines will have their own multi tap transformer inside for adjustments, some do not.
 

BT Fabrication

Stainless
Joined
Nov 3, 2019
Yep Im guessing the lower voltage before had put less stress on all the components, and now running 238-242V might be putting stresses on older components and I'm just finding all the weak points. Probably doesn't help inside the cabinet is covered in black sticky oils all over every circuit board from the previous shop.

plan now is to find a dedicated 240V to 208V 3ph transformer for it and hopefully alleviate the high voltage issues i think I'm having and might reduce the spikes from the spindle stopping at the same time.

At least it ran a bunch of cycles before it ran again for 8-10 hrs of spindle on time before it broke again. Looks like someone was in the spindle drive before also replacing parts like resistors caps etc.
 

Ox

Diamond
Joined
Aug 27, 2002
Location
West Unity, Ohio
Well… it’s broken agai

well it broke again. Ran fine for a couple weeks, then threw a random fan fault code,
And just completely failed differently.
Thinking I lost or shorted something in the spindle drive.
Plugged in and it’s 14V on the 24Vdc
Unplugged and it’s 23.8V but still fires up with an over current fault in the DC Buss. Code 07 on it.
Spindle amp has power still and is on
Servo amp has no lights that jumps from the spindle dc output
Just ran it at 8000rpms, and turned the spindle off when it failed. And tripped the fan fault only
And 30 sec later or so it completely shut down.
Guess it’s pulling both and bringing them to my repair guy.


IDK what you think dropping input V is going to have on your 24v being pulled down?

Sure sounds to me like you either have a defective P/S or there is something pulling it down.

I'd start unhooking things 'till your V comes back up, and then - if it does come up - figger out what is pulling it down.

Is it a short?
Too much load?
Or maybe the P/S is weak?

I don't see how an external X plays a role here?


------------------

Think Snow Eh!
Ox
 

BT Fabrication

Stainless
Joined
Nov 3, 2019
it might mitigate any voltage spikes when the spindle stops and regens back into the input current.
ya could be the power supply not supplying enough 24V or it could be a short in the spindle amp,as when it was plugged in on the 24V it was at 14.1V on the Power supply
guessing its all of the above, fix one fault but find the real issue behind that.
although guessing somewhere on the 24V as the servo amp further down the line wasn't on and didn't have it plugged in and power supply was still at 14.1V
bringing the repair guy both pieces just in case.
 








 
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