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Overcurrent Alarm only when moving x,y simulatniously

TDIBABY

New member
Hi All.

I have a new to me 93 HAAS VF-3 ive had it a short while. and have just gotten it up to be able to run it. Basically it runs fine from what i can tell. ive ran 2 jobs on it so far over the last couple weeks. The only real issue i come across is that when the rapid is set to 50% or higher. (looks like the machine powers up in 50% by default) Ill get an overcurrent alarm ONLY when its a rapid movement along X and Y simultaneiously. (on the same line of code)i can let it run in 50% and will not alarm out if only moving one axis. either x or y. Any ideas on what i should be looking for to try to solve this?
 

magno_grail

New member
On my '91 VF-1 the over current alarm comes from the voltage measured across a resistor on the servo board. Possibly the servo voltage (165 DC) is sagging which causes the machine to put more current through to make the speed. More current through the resistor will be seen as an over current.
 

TDIBABY

New member
220 3 PH it is on the last tap. which is the 260-244 as the voltage falls in that range. The Machine has been Runing Okay. But Nowim getting a 160 Low Voltage alarm. I measured the voltage in the servo power dist board. Looks like 160v DC GOING OUT to each servo amp, but the buss voltage in the parameter voltage varies.. it will be at like 115 then float around from there to 150 something then back down.now and then ill be able to run the machine but then when the voltage drops it alarms out again. Any ideas Guys? Is the servo dist board bad? Anyone have experience with similar? ive seen other articles and forum posts about not outputting 160 or just no voltage. but this one seems to put out the correct dc voltage to the drives.
 

Turbo442

New member
How do the ball screws sound? Can you jog at 100% for each individual axis and see how the load meter looks? Maybe you could narrow it down to a specific axis?

Sent from my iPhone using Tapatalk
 

magno_grail

New member
The monitor voltage comes from the Power Monitor board, P9. If the buss voltage is correct and the monitor voltage is wrong there are a few components in that circuit.
I found R20 burned on my board.
PowerMonitor.jpg
 

TDIBABY

New member
Took me a bit to find this again... something to check here w/ a diag and usual semiconductor parts to swap/check. There is one other long doc I've seen w/ Pics of the area and the potentiometer adjustments for the older DC unit but.... they are being stubborn to find.
Redirecting to https://www.*******.com/forums/haas-mills/51041-vf-3-low-dc-buss-voltage.html

I read thru this Post and it seems exactly like the problem i am having. the voltage is fluctuating and ive disconnected all of the axis individually and ultimately all at once and the voltage still showing that it fluctuates. i went ahead andorderd a servo dist board. and it should be here Tuesday. so we will see what happens once i swap it.
 

countryguy

New member
yep. :) Was assisting someone else upon a time and recalled this one. Was it an exchange for the board? It does not look difficult to repair and you'll have a spare. Happy Holidays! When you get the newone,
Q: Mr. MagnoGrail may know this better- Is this where the pot is for adjustments? (again, cannot find the post, but there were some adjustments for OV threshold and something else(?)f needed potentially). Peace and happy holidays all!
CG
 

countryguy

New member
Yep... It's in MG's print. "Clamp" pot... ("Ya got it; haul it up". stupid the-Sandlot movie quote LOL). There are a few pots on the print. OV, Clamp and AD. :)
that's a good print! into the archives now. Whoot! :bowdown:
 








 
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