Haas VF3 - Wonky Power Behavior - Alarm 850 I/O Board Errors - Powering Up Issues

[KC130Loadie]

I got an interesting one for everyone.

My work has 2 VF3's that are almost identical. We machine plastic, so the spindles were changed out with after market grease packed 30k spindles, with chiller units.

The problem VF3 is a 2012 model. The sister VF3 is 4 months younger. The problem child has the pre-unified plumbing manifold. That is the only difference as far as I know.

here's the deal:

When turning on the machine, not always, but often, you have to hold the power button down about 20 seconds into the boot sequence. If you just mash it and let go like any other machine, the machine shuts off. It is as if the contactors don't stay closed.

Our power appears to be stable voltage wise, and the transformer is tapped for the voltage range from what I read with a multi-meter as our supply voltage.

We have had issues with the 3rd Party spindle in the past, and its' PLC communicates with the Haas control very minimally.

Other issues that have cropped up is an 850 I/O alarm code, and a 133 Spindle Inoperative code. If the 850 pops up, the machine has to be powered down completely...there is no resetting it. I think the 133 code is a combo of the 3rd party unit and Haas control not getting along, but this machine has been in production since 2012. The sister machine next to is is solid as a rock.

I did start digging and comparing machines, and the sister VF3 transformer taps are set to be undervolted from what the supply voltage is.

Anyone have any ideas? Bad contactors? Transformer giving up the ghost?

We at at the end of our power companies' system, and I have been told historically in the past, our voltage would fluctuate pretty wildly...especially when it gets hot (like now) and people start running their air conditioners.

 

[Turbo442]

Have some one check the three legs coming out of the contactor when you hit the start button.

 

[machineit2]

I'm thinking that the coil for the mag starter is weak or the hold contacts are faulty. Check the contacts.

When you hit the power button, the coil is energized and pulls the main contacts closed to supply power to the machine, but it also closes a smaller set of contacts that keeps continuous power to the coil. When you hit the power off button it interrupts the current to the coil and the main contacts drop out.

Either your coil is weak or the contacts for it are burned and pitted.

This fix is of course for the need to hold the power on button for several seconds.

Mike

 

[haastec]

I'm thinking that the coil for the mag starter is weak or the hold contacts are faulty. Check the contacts.

When you hit the power button, the coil is energized and pulls the main contacts closed to supply power to the machine, but it also closes a smaller set of contacts that keeps continuous power to the coil. When you hit the power off button it interrupts the current to the coil and the main contacts drop out.

Either your coil is weak or the contacts for it are burned and pitted.

This fix is of course for the need to hold the power on button for several seconds.

Mike

+1

I had the same exact issue about a couple years ago and a new contactor fixed the problem.

Good luck!

 

[KC130Loadie]

Contactor - WIll inspect

Got it. I'll give the contractor and its' associated systems a look today. Thanks for the pointers! I'm 99% sure that is going to be exactly, or at least directly related to many of the issues we have had. I'll update with results.

 

[tpkl91]

+1

I had the same exact issue about a couple years ago and a new contactor fixed the problem.

Good luck!

Also check the low voltage! the low voltage power supplies go bad as well +12VDC -12VDC and 5VDC

 

[KC130Loadie]

+1

I had the same exact issue about a couple years ago and a new contactor fixed the problem.

Good luck!

Nothing like having too many hot projects all at once to prevent updating my own thread. I had almost the whole day today to pull the K1 Contactor and give it a look. It had a little pitting presumably from arcing, but I have seen much worse that were working fine in the past. I checked my input voltages, voltages to the Power PCB, power to the 24VAC transformer (which supplies the low voltage to the power button / power off button and contactor, and everything checked out great...except that it was still taking 20 tries to get the machine to stay on. I also checked the power on both sides of the breaker and contactor when it was opened and closed and didn't find anything wrong.

I completely disassembled the contactor to paper up the contacts, but the coil itself seemed fine. Now, it is my understanding that once the breaker is set to ON, the Power Distribution PCB receives 115 VAC & 230 VAC from the T1 transformer. The 230 VAC is fed to a transformer T5 that steps it down to 24 VAC that then returns into the Power Distribution PCB, and then to the Control Panel Power On and Power Off buttons. When the power button is pushed, that directs 24 VAC to the K1 Contactor Coil, closing the contacts and bringing in 3 Phase 230VAC. Once the contactor is closed and the machine is booting, 24VAC should be automatically applied to the secondary coil / relay that keeps the contactor closed until the power OFF is pushed, which removes power from the secondary coil and the contactor drops out, cutting power.

Am I correct in my understanding?

So, I even checked out the power buttons in the pendant and inspected the cables just to be sure. I was able to physically close the secondary coil (on the side of the main contactor) and the machine would power up no problem. I checked to make sure that both coils were seeing 24VAC during power on and at least when I tested them, they seemed to be.

The cable that is involved with the coils, both primary and secondary is a 6-pin molex style plug that has 2 sets of leads that run to the 2 coils, and one set goes to the I/O PCB to P42 Auto Off. What I couldn't determine is does the 24VAC run directly from the Power Distribution PCB to the power buttons directly, or does this have to pass through the I/O PCB in any way? I am assuming the P42 Auto Off connector and its' leads are for when you enable Power Off @ M30?

I am going to replace the contactor and it's coils just to eliminate them from the equation, but if I have an I/O board that is dying, could it in anyway cause the power-up problems that I've been experiencing?

Thanks for the help and getting this figured out. I think I'm pretty close.