take a look at your pierce delay time…we find that if it is too long for the material you are cutting eventually you end up with a hole and therefor no arc, therefore no THC voltage for the logic to try and keep constant…also, look at your air pressure and volume, prehaps the plasma machine is turning off due to low pressure…
good luck
MikeP
Polarity could be reversed for the THC signal. That would make sure fire control shows zero volts. ?
The cutter is fine. It worked perfect will my old 2x2. I used the new black box and gave the old one to the guy that bought the old table. I am pretty sure it just is a faulty vim box. I need to reach out out to langmuir systems.
I’ll hop in on this conversation. My THC has never worked the way it was intended. I’ve never contacted Langmuir about it because I didn’t want to chase gremlins. When I first turn on the machine and for the first cut of the day, firecontrol will read 0 volts. I know that THC will not work. I will check the voltage periodically until it stabilizes. So torch off, should read 0, it will stabilize anywhere between 12volts and 30 volts. I can now use THC. I’ll add that 90% of the time I cut with it off. The only time I use it is for cutting 18 gauge and thinner. I haven’t taken on any jobs that require tight tolerances yet. That will come soon and the first thing I will do before I troubleshoot this THC issue is drive a ground rod into the ground so that I have a dedicated equipment ground. Next will be Isolated ground for the rest of the electronic outlets.
My house is old and still has one or two outlets that aren’t grounded. The previous owner had most of the electrical upgraded and grounded. I’ve noticed that corners were cut and the importance of identifying and rectifying common-mode voltage (electrical noise).
Electrical noise is a general term used by the professional and layperson alike to describe an event that disruptions the operation of electronic equipment. The correct term for it, though, is common-mode voltage. Common-mode voltage is an unwanted signal that occurs between circuit conductors and ground that can mimic intended signals between devices, often at the wrong intervals. Specifically, the common-mode voltage between neutral and ground is of the utmost concern for power supply designers. This is because there is a lack of filtering between these two points within the equipment’s power supply. As a result, a disturbance that is generated on the ac side of the power supply (i.e., the ac grounding system) is common to the dc side (known as chassis ground), hence the term common-mode.
Nearly all equipment, with the exception of incandescent lighting, is a source of common-mode voltage. Any device that contain motors will direct-couple common-mode currents to the equipment grounding conductor. These include vending machines, copiers, laser printers, refrigeration units, UPS’s, etc.
Studies have also shown that loose connections on the equipment grounding or neutral conductors that are subject to mechanical vibration may also cause mid-level electrical noise or could compound the problem where there is an existing common-mode voltage. Other sources can induce a voltage on the grounding circuit via electromagnetic interference (EMI) or radio frequency interference (RFI). Radio/TV antennas, motion detectors, two-way radios, cellular phones, pagers, and fluorescent lighting bring about these types of disturbances.
Regardless of the source of the disturbance, it is accepted by the (IEEE) Standard 1100 (Emerald Book) that any voltage greater than 1 volt between neutral and ground at the input to electronic equipment will likely cause equipment malfunction.
I love the guys at Langmuir and I think they do a hell of a job trying to help solve these issues. When it comes to electrical issues, there are just too many variables involved for there to be an all inclusive solution. They don’t have the resources to assign an electrical engineer to each case. So they are going to send parts and suggest solutions until something sticks. I’m not an electrical engineer, I am a former licensed petroleum engineer. I have had conversations with engineering friends including an electrical engineer.
Lastly, my brother bought an arclight table. A dedicated equipment ground was required for installation.
What Plasma cutter do you have and are you using raw voltage or divided? If divided did you make the connector up or was it a factory harness?
I have a hypertherm 65 sync. Using the plug and play cable from Langmuir.
Interesting… The good news is you have the top of the line plasma cutter with a reasonably known good harness. You’re saying that the first cut of the day during the cut voltage reads zero? But after a little while and a number of cuts it starts to read a stable voltage?
No, when I first get the machine turned on it will read zero. I know it is not going to work when I fire the torch from experience so I turn it off. Once all of the interference stabilizes, it will show between 12 and 30 volts with the torch off. Now I can turn THC on and it will work. I have two issues going on, first I have way to much interference. Second, I am not getting a reading when my torch fires.
Try not to laugh… When I do cut with THC on, it is working based on interference. For instance, if the THC says 20volts with the torch off, I run a program and the voltage will not change much when the torch fires. Like a few decimal places between pierce height and cut height. So I know i’m not getting a signal from the torch. However, if the material is warped, somehow it causes enough change in my voltage to allow the torch to respond.
It’s one of those things that I’m confident can be fixed. I just need to throw the time at it. What are your thoughts?
Do you ever see anything approaching normal voltage on the readout somewhere around 150 volts?
I would recommend following the thc troubleshooting flow chat. It is pinned on the forum if I am not mistaken. That is the easiest way to eliminate factors.
Never that high. I think I’ve seen around 100. This is with the torch off.
I’ve read it, I’m going to drive a dedicated ground rod first. If I know my grounds are good, it will eliminate a bunch of tail chasing.
Don’t take this the wrong way but are you sure you have the cables plugged into the VIM correctly? You shouldn’t see voltage anywhere near that without the torch firing. You can’t go wrong with the ground stake but many if not most of us don’t have that. I’m curious if you have continuity between the USB connector and the table.
No worries, I don’t have feelings. I’m pretty sure I do. It goes into the input?
coming from the cutter it should be in DIV input and then DIV output goes to THC on the control box.
I don’t have anything connected to the output or the THC on the control box.
I didn’t get a cable that would connect to those locations. I got the Hypertherm plug and play from Langmuir and a cable I ended up not using because it has a pigtail connector for wiring directly to your plasma cutter.
Sounds to me like something is missing. If you have an input to the VIM and no output along with no connection on the THC connector on the control box I don’t see how it could possibly work. Seems to me you need a cable.
If you want post a picture of your VIM and control box so we can all be on the same page.
