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Alarm 880 under voltage on 160 volt DC Bus at tool change

evotechcorp

Plastic
Joined
Sep 16, 2019
My mini mill has started giving me an alarm 880 "under voltage on DC bus" upon attempting tool change. the tool changer slides to the out position and the prox bit changes as it should but alarm 880 stops the process. I can recover the tool changer and the home prox sensor bit also changes as it should. I've swapped out the main 320v power supply and the 115v power supply, not sure where the 160v is generated from must be I/O board? Anything I can find online regarding this points to Vector drive which a minimill does not have. I've verified the vector drive and power supply parameters are correct. Not sure where to go from here other than replacing the I/O board? Any thoughts would be appreciated.
 
UPDATE - swapped out the I/O board, pulled and checked the shuttle motor which is brand new, performed continuity and short testing on cables. Upon pulling the shuttle motor I noticed it's a 90 volt motor so where is this 160 volt error coming from? I'm kinda at a loss now unless maybe theres a software problem? I would say parameters but nothing has been changed since I added the fourth a while back and everything was working fine until just recently... Anyone have any suggestions?
 
Well, swapped out the Mocon, cables, and regen. Loaded factory parameters. Have literally replaced just about everything and still getting alarm 880. Time to call Haas
 
Hello evotech Corp, just wondering if you were able to solve your problem as I am experiencing the exact same on a 2015 haas vf6. I am currently combing through the service manual looking for answers. Have a call in to haas as well but they said they are so overwhelmed right now they dont even know an ETA! Best reguards.
 
Hello evotech Corp, just wondering if you were able to solve your problem as I am experiencing the exact same on a 2015 haas vf6. I am currently combing through the service manual looking for answers. Have a call in to haas as well but they said they are so overwhelmed right now they dont even know an ETA! Best reguards.

Hi Everyone,

We have a TM-2P and had the same issue. We got a MOCON board (2nd hand) swapped it and same goes, got someone to repair the circuit on that end (TC out), on first board (they replaced capacitors and triacs) but it keeps with sending the alarm.

Did anyone solve it, do we need to do a Hard reset for clearing the error, when swapping boards?

Any help would be gladly appreciated.
 
Hey. I'll type some notes I had upon a time. For the life of me I cannot find a Support/service TM MM2 guide again. I had it up some time back helping someone out. If you have a link, let me know - What I recall reading was the HV DC was developed from one of the Axis drives. I think Y? so while the VF (like I own) has a Vector drive unit w/ the HV DC buss source in there, the MM had some actual text in the electrical support docs that noted the HV DC 160 was developed via one of the axis drive units? boy.... I may be fuzzy there but I just spent 20 looking for a PDF... pop a link if you have one and I'll re-read.

again, somone pop me a manual and I'll find the page.
 
I would replace or add capacitors to the dc bus.

Its common to run a "90" volt motor from a far high voltage especially if its an off the shelf motor used in a servo application. So dont waste your time looking for the 90 volt bus, or the 160 volt bus. Actual voltage doesnt matter within reasonable limits.

Usually voltage measurement circuits have a divider resitor string and an rc filter. If that circuit degrades then you get a false error.


Hook up an oscope to the dc bus and if its voltage ripple is good then trace the circuit and look for how the intelegent brains of the system measure the voltage
 
Hi guys,

Thank you for the answers. In our case, the machine works perfectly if we disable the tool changer, we are using the machine right now using the parameter 710 on manual. It has something, on one of the motors of the tool changer, this one has an umbrella type, and when the motor that moves it forward actuates and reaches the spindle immediatly we get the alaram 880.

I said we replaced Capacitors and triacs on the MOCON board, I meant the I/O board on the P59 end (my mistake). Will re-check with your feedback (@johansen)

@countryguy
I found this link, is this guide you were talking about:
https://www.academia.edu/34285996/Haas_Technical_Publications"]https://www.academia.edu/34285996/Haas_Technical_Publications


Does anyone know how to reach the menu where we can control each motor separately (manually)?

Thanks for the help. :)
 
Hi,

Thank you for answers.

First, I want to apologize, I said the MOCON board but I meant the I/O board - The components replaced were on the P59 end (TC out).

lINK I/O PCB - Troubleshooting Guide - CHC

at the end of that page we can find the wiring diagram.

The fault starts when the shuttle moves forward towards the spindle, or backwards after recovery. Is it any bad feedback from the motor and not an issue with board?
 
I have a spare Power source unit and a circuit breaker board, swapped both on the machine and alarm keeps popping, but now the shuttle won't move forward. We get the alarm immediately after the spindle gets in position for tool changing.

A new alarm shows up now (besides the 880), Alarm 859.
 
Hi I could with some help as well as soon as tool changer goes out it stops round tool fault 880 low 160v dc can bus
 
My mini mill has started giving me an alarm 880 "under voltage on DC bus" upon attempting tool change. the tool changer slides to the out position and the prox bit changes as it should but alarm 880 stops the process. I can recover the tool changer and the home prox sensor bit also changes as it should. I've swapped out the main 320v power supply and the 115v power supply, not sure where the 160v is generated from must be I/O board? Anything I can find online regarding this points to Vector drive which a minimill does not have. I've verified the vector drive and power supply parameters are correct. Not sure where to go from here other than replacing the I/O board? Any thoughts would be appreciated.
Did you manage to solve this? I have same problem on my minimill.
 








 
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