LW4000 VT Board warning

[GoBuckeyes]

Does anyone know what a warning #5 means on the VT Board? The description reads ‘re-synchronized counts’ but that doesn’t mean a lot to me.

Whatever it is, once it happens my trolley seems to go wide on the passenger side of the car on all passes coming home. Trolley will go dump for first persoak pass then go straight across the front of the car without creeping first. Trolley creeps out at the start of every additional pass to the correct distance for the passenger side but once it goes across the back it will go wide.

It seems hit or miss as well. Sometimes it’s all day for every car. Sometimes it’s just a few cars and then it’s fine?

 

[JGinther]

It means there was a discrepancy on the count prox. It didn't see the same counts from the middle gap that it was expecting to see. About a hundred things can cause it. Machine drifting, rusty count bars, damaged prox, qc wire, festoon cables, sloppy rollers... to name a few. Start with checking the count prox operation. I know of some machines where that error persisted, even though the machine still sized right. The error would show up on the first pre-soak pass every time, but wash the car just fine. I suspected a vt board, but it wasn't worth changing until there was a real life problem.

 

[GoBuckeyes]

Thanks JGinther. I wouldn't have known there was a VT warning had I not turned the switch to the 2 position to check. The errors/warning light on my VT board wasn't lit up? We just swapped bridges in this bay with a newly rebuilt stainless bridge. All rollers are new, proxes are new, Picket Fence is new, Festoon is new. I'm not sure if my X30 cable is new or not. When I talked to a PDQ tech (before I knew there was a warning code) and explained what was happening his best guess was noise interference messing up the X30 count at the rear. He said 90% of the time operators experience the problem at the rear because the festoon is bunched up and acts like an antenae and running a shielded prox cable all the way back to the JO normally solves all these issues. Not exactly what I want to be doing right now.

 

[JGinther]

I don't think that error is a true error... its more of a warning. I think your tech is right with all those new parts. That is always a problem on lasers. They should have used a shielded cable design for the VFD cables and grounded the shield at the panel. The antennae effect they are talking about is most likely related to emf from the VFD. They require installing a Toroid core magnet with the VFD winding through it to help with that, but I don't think it actually fixes the issue. Do you have the Toroid core installed?

 

[GoBuckeyes]

If you are referring to the donut hanging under the drive that the wires wrap around then yes I do. I didn’t realize it was a magnet.
I have been watching countless washes from my cameras to help identify the issue. What I have concluded is that I can tell at the beginning of a wash if it is going to go wide on the passenger side or not. The trolley will either go dump, creep out to the edge, pause for my 3 seconds and then go across which means it will wash without issue. Or it will dump, pause WITHOUT creeping and then go right across the front. Go wide on the passenger side for every pass and it will also creep out to the front corner on all the remaining passes? The fact that it goes wide EVERY pass makes me think it’s not actually a counting issue because you would think there would at least one pass where it gets it right. Why would it not creep out on that first presoak pass, it hasn’t had to count anything yet?

 

[JGinther]

One thing I know for sure is that it's an overcomplicated mess. I know there's a relay in the main cabinet that redirects the x30 pulse from the x30 input and directs it to the vt board input. You might try changing that relay for the heck of it. Would be hard to troubleshoot since it is working some of the time. I don't know what the software is thinking, so it might not try the next wash based on the previous wash having a reencoee error. Don't know on that though. Pdq doesn't supply vt controller 'logic' with the vt manual.