Grounding A Laser

[Walt Langhans]

Hey Guys,

So the manual says I need to ground my laser, I'm not 100% sure if it necessary given how electricity works here in states but I also figure it can't hurt. My issue is that I know just enough about electricity to be dangerous. I know that for a proper ground you have to have a certain level of resistance but I don't know what that is. I also know that depending on the ground make up it determines the width and length of the grounding rod. I've got a lot of clay in my ground so I figure I'm probably going to need a bigger than usual rod. Any advice on this matter would be appreciated.

Thanks

[Matt Turner (physics)]

Does it say you need to do anything more than use a power cord with a ground connector? I wouldn't think that you need a dedicated rod for the system.

[Mark Sipes]

Does the laser not have a UL listed 3 prong plug with ground? No better ground that the building you are plugged into. If not I would run a new plug cord from the laser power and the indicated ground on the machine. The plug should have blades that are of different widths so it will only plug in one way. If not I would question the safety of the machine......no standards

[George M. Perzel]

Walt;
The Chinese are notoriously undisciplined when it comes to grounding-many times providing systems with two-wire 220 volts and no ground-a dangerous situation. I recommend that you install a heavy duty ground post at the rear of the machine-scrap the paint away and make sure your post is screwed tightly against the metal case. The Shenhui unit should have a three wire power with one of them the ground-make sure all of these ground terminals are connected to each other and/or to the ground post. Then check that all of the machine steel parts are grounded together and none are isolated by paint layers. Then connect a 14 gauge ground wire to the power supply case and then to the ground post. Check everything with a good ohmmeter. You can probably get away using your house ground if close to your power panel-connect the ground post to that with about 10 gauge wire or to new ground rod if easier-Google ground rods and you will find an easy way to drive an 8 ft rod into the ground using water and little effort in about two hours. If you install the ground rod, the power plug connection in the laser will insure that house ground and rod ground are the same. Get yourself a decent commercial surge protector-220volt type .
Good Luck
Best Regards,
George
Laserarts

[Doug Novic]

Walt,

Not sure if this helps but I drilled the metal case, bolted a copper ground to it and joined the other end to my existing ground rod. Just a precaution.

[Dan Hintz]

The ground rod is overdoing it, IMO... just make sure you have a good connection from the machine to the ground at your outlet. Your outlet should have a good-quality ground already to the box, and then itself to a ground rod. Adding a ground rod 20-30' closer should make zero difference if your building as a whole is wired properly.

I believe Rodney used a ground rod and saw an improvement with errors he was having, but I also believe the electrical setup in South Africa may not be to the same standards as the US. You'll have to wait for him to chime in if otherwise.

[Rodne Gold]

I have a mixture of 2 and 3 phase power incoming with 2 added distribution boards. Old building with lots of wiring all over..been phase balanced and checked but I used grounding rods to make sure. Solved all problems.

[Walt Langhans]

Thanks for the replies guys!

The manual does say to ground it by attaching a metal rod in the ground to the frame of the machine via a copper wire. Granted this is an Chinese manual for a Chinese machine and they may have just not omitted the section on grounding when they send out ones that are compliant to US regulations. There are two 3 prong 110v plugs that come with the machine, one for the laser tube circuit and one for the rest of the electronics. The machine will be in my garage of a house that has been built within the last 10 years and the wiring is up to snuff. But as George points out, since it's a Chinese machine designed for a different electrical system there could be some issues.

Anyone been running their Shenhui here in the states without grounding it and without and issues?

[AL Ursich]

I believe the last post mentioning two three wire power cords plugging into a properly installed and grounded American Electrical System is the way to go.

I DO like the idea of going around inside the unit and with a Quality OHM meter confirm that all metal parts are bonded or attached to the 3 wire Grounded plug. The painted surfaced idea is GOOD too checking bonding between metal sheets or parts.

I DO NOT like the mention of using a Ground Rod in the American 3 wire system due to a little problem called "Ground Loop" What happens with a new installed Ground Rod at the piece of Equipment and the Equipment also Grounded to the American 3 wire System is you get "Ground Loop" http://en.wikipedia.org/wiki/Ground_loop_(electricity)

What can happen is that the Frame of one piece of Equipment in the Shop could have a Higher POTENTIAL Voltage due to Ground Effect or Ground Loop.

That is why in an American System there is a Bonding Screw inside a Service Panel or Fuse Box. The First Box after the Power Meter has the Bonding Screw Engaged. I have 3 Sub Panels off my main 200 amp service. None of the Sub Panels have the Bonding Screw Engaged.

http://www.nachi.org/forum/f19/siemens-distribution-panel-bonding-screw-installation-42274/

Good Luck with your new Laser.

AL

[walter hofmann]

hi guys
just my two cents to this I runn my chinese laser machine here in florida since three years and I had some issues in the beginning too first what I discovered was that the three prong plug what was in the machine was not connected to the machine ground at all and was the different kind anyway i replaced it with the US standart plug, and groundet all parts of the machine to this ground and my house is only 10 years old and to the latest code ,but I still had issues and I then put a 6foot groundig rod outside its only 4 feet away and connected the machine ground to this with #10 gauge wird to the rod and since then I had no issues anymore. my machine stand only 3 feet away from one mainpanel.
greetings
walt

[Walt Langhans]

Rodne and Walter what where the issues that you where experiencing that where fixed when you grounded your machines?

[Rodne Gold]

Intermittent operation , laser firing and then inexplicably not firing or firing continuously, mainboard crashing and a few others I forget. I think the grounding may have more to do with removing static or some interference .. suffice it to say , we tied all grounds we could find on the machine to a main ground at the back of the chassis and then to a rod. My laser didnt even have a grounding bolt on the back when I got it. I think I went into more detail in that sticky thread at the top of the forum when describing my unpacking and commissioning.

[walter hofmann]

Hi walt
pretty much the same complitly eradic behaviour but not consistend every time something else.
it has to do with interference because the most have the wiring put together in strands but all kinds from the digital over low voltage to mein power lines.
I had after grounding no problem anymore.
greetings
waltfl

[Jerome Stanek]

Can you do a continuity test between the ground plug and the frame to see if it is actually grounded.

[George Brown]

Al, you are absolutely correct with the ground loop problem. Must be avoided at all cost, and can cause major problems with electronics. All grounds must be bonded together. If you have lightning rods, they must be bonded to the electrical ground also. Multiple grounding rods are ok, as long as they are all bonded together.

[Dean Fowell]

I used a Ground Rodd with my hammer Drill I have also used Ground Rods with Hi Def plasma Machines ans Bigger Lasers, But that's what we have always done so I did it to mine did not hurt at all.

Cheers

[Richard Rumancik]

I am not an electrician, but my take on this is that if the machine has a proper green or green/yellow ground through the power cord then it will comply with electrical code requirements. The electrical code does not prohibit supplemental electrodes (that are connected together) as this will not reduce safety. But it might not be the best thing for your equipment performance.

If anyone uses the separate ground rod, you do need to wire this back to the main building ground (with heavy gage copper wire). You can't have it on it's own, nor can you use this as the only ground.

The electrical code is mainly concerned with safety, not with EMI/RFI issues which is probably what is behind the problems people are seeing with these lasers. If I suspected EMI/RFI I would probably try to address it with other means such as a input EMI filters, a Transient surge suppressor, an isolation transformer, an uninterruptable power supply, or a combination of these.

Although some people have had "success" with a separate ground and others have concluded it did not cause new problems, it is not necessarily the correct or best way to address the issue.

I did a bit of research on the use of separate ground rods and based on what I see I would not do it. Here's one reference:

http://www.copper.org/applications/electrical/pq/casestudy/grounding.html

Look at the section entitled: "Grounding and Network Signal noise" especially the last paragraph. In this particular case, a shop with a lot of CNC equipment was having problems with glitches etc and found that the solution was to remove the supplemental ground connections and install a proper grounding system.

If someone is having some problems they might be able to get some free advice from their local electrical utility. At the minimum they can check the supply up to the entrance box to ensure all is correct on their end. They may be able to give advice on what auxuillary equipment would solve the problem.

I am surprised that these Chinese machines can be imported into North America if they do not have proper internal wiring and grounding. They would not have been able to be certified for UL, CSA or CE compliance for electrical safety if the power inlet was not grounded to the chassis and all metal parts were not grounded to each other.

[AL Ursich]

I am surprised that these Chinese machines can be imported into North America if they do not have proper internal wiring and grounding. They would not have been able to be certified for UL, CSA or CE compliance for electrical safety if the power inlet was not grounded to the chassis and all metal parts were not grounded to each other.

I think that what is submitted to the UL and such is correct and PASSES then what is actuall mass manufactured may not be built to the same standard... "so sorry..... we missed that on YOUR unit..."

AL

[john banks]

I noticed some FM radio interference related to the stepper motor power supply on our Shenhui. I tried some ferrite cores on the wires to no avail. This may be relevant to noise issues, but I see no glitches.

[Rodne Gold]

Here's quite a good article
http://www.blueguitar.org/new/articles/other/ground_loop.pdf
Read the subsections re building grounding etc.

[Julian Harrison]

Had a qualified electrician stop by and inspected our new 80watt RedSail X700 laser machine for bonded ground and to get his professional suggested for the ground screw post in the laser unit back. He told me the electronics are all ground bonded and the three prong cord grounded this. He also mentioned that some of the internal power components produce power. It might be possible for any extra power to find its was to the unit's housing (maybe static maybe extra power). This could cause a shock. Since our building is code then the 1/2 inch electrical conduit is ground back to a ground rod. It is OK to attach a ground clamp to this conduit and attach a #10 wire running from conduit to laser machine with lug. The solution was simple and well worth the service call price! He also verified the unit power was set to 110V and where it was written 15 amps. One other note that may be of importance. He said these laser machines from China have some internal components that are from Germany. This makes sense since I have read parts of the actual laser tube are from Germany. Hope this helps.

[Bill George]

As a licensed master electrical (retired) with real world experience dating back to 1962 I can tell you trusting your life to a conduit ground is not ok. You should have the same size green equipment grounding wire as the branch circuit running all the way back to the main panel and connected to the main grounding terminal block. I have seen conduit installed without locknuts and with loose locknuts inside a box. Loose connection = not grounded Laser power supplies can have 20,000 volts output and all it takes is one lead touching the cabinet metal and no valid ground.

[Kev Williams]

A main reason for grounding often 'glossed over' or not mentioned in electrical explanations is the simple fact that a path to ground is needed in order to blow the circuit's fuse or trip it's circuit breaker in case of a hot fault. I'm no electric genius by any stretch, but *as I understand it* (< disclaimer!), breakers and fuses blowing when they should is also a good reason why extra grounds should be avoided; main and subpanels are grounded differently, and grounding something in more than one place can cause ground faults and neutrals being energized in some hot fault situations. Meaning, if your electric system's ground checks out, you should use it, but if you install your own ground rod, use ONLY it, not both...

Bill will correct me if I'm wrong :)

[David Somers]

Walt,

I think George is on the money with his post near the top of this thread. I saw the same issue on my machine from China. They use a 2 wire 220V setup. 220V is their standard native power at the wall, like our North American "at the wall power" is 110V. In their system they need a separate grounding wire and the companies recommend using a ground wire to a long metal post driven into the ground.

This initially caused me no end of confusion, and also caused the company in China confusion as we discussed it. I would not plug anything in until I was sure I was wired correctly. Talking to local electricians here was no help either. They swore the wiring they saw on the Chinese machine was 110V, not 220. The Chinese swore it was wired for 220V even after I sent copious photos. I finally ran across an electrician who had worked in Asia and was familiar with the Chinese power. He knew right away what the issue was.

Hope that helps.

[Julian Harrison]

Same issue, but power supply has switch 220v 110v we verified 110v was set. It is from China but most components are from Germany.

[Bill George]

Same issue, but power supply has switch 220v 110v we verified 110v was set. It is from China but most components are from Germany.

If the Chinese laser comes set up for European 220v then both incoming wires together are assumed to have 220v across the pair. There is no Neutral, or normally white wire like the US. The ground pin is just that, a equipment ground, not to carry current. If your power supply was set for 110 , it would have let the smoke out, just a one time deal. I had a Chinese laser, I don't recall any Made in Germany parts?

[David Somers]

Bill,

When I was struggling with this issue I was told that it is not uncommon for Chinese 220V power cables to have NO ground wire. So you have a simple 2 prong cable like you would find on one of our 110V lamps or other devices like that, but as you said, the two prongs are each carrying power across the pair. No Neutral. The key is to remember that in China, 220V is the standard at the wall like 110V is out standard.

The main power cables for my laser were 3 prong, but in what we would consider a 110V configuration. And the company recommended a separate earth ground. They eventually explained that is because in China many homes and businesses have inadequate or no grounding. When they realized I had a solid and tested ground for the house they said dont worry about using the earth ground. And when they found I was using dedicated 220V for EACH 220 plug they had, and had a whole house surge suppressor and a voltage regulator on the laser they were delighted and amazed. I explained that in the US, electrical code usually calls for each 220V device to have a dedicated circuit. I might add that the laser itself has 2 separate 220V power inputs. And the Chiller was 220V. And the water pump was 220V. And the blower was 220V. For some reason the air assist pump was 110. So by our electrical code that was 5 dedicated 220V circuits to run the laser. Plus I had a CNC as well which took 220V for the CNC. I picked up a local blower for dust collection for it so the CNC only took 1 220 V circuit. If I did this again I would have asked for 220V for the laser and 110V for everything else and saved myself a lot of crawling under the house pulling wire.

This is fascinating stuff. The difference between standards and approaches to safety is so interesting to see.

[Julian Harrison]

There could possibly be a switch inside the laser machine power supply that can toggle between 220V and 110V, possibly you can view it with a flashlight and close inspection. Some of the housings have lots of holes.

found this if you want to set up temp gauge with sensor http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dcomputers&field-keywords=4+Pin+Molex+pass+through+connector+5V

to run it this: http://www.amazon.com/AGT-External-Power-Supply-Adapter/dp/B00B42UTFO/ref=pd_cp_23_1?ie=UTF8&refRID=0DZQBRY9J691Q4BYJ063

I post this because the power brick does NOT have a ground!

[Keith Winter]

For what it's worth when I got my chinese machine I had a commercial electrican double check the entire machine to make sure it was grounded. He said it was all grounded so at least in my case the 3rd prong was grounding the system like in a normal 220v setup. He took a lot of time and care to look it all over with one of his colleagues to make sure it was done right so I feel good about it. He did however cut off the end and put a new 220v cord on to make sure we didn't plug it into the wrong socket :) I think with the chinese machines your mileage will vary from machine to machine and supplier to supplier.

[Walt Langhans]

Hey guys! Well it's been a while since the original post but I never grounded the machine (other than it's normal ground thru the wall socket) Since then I've blow a few fuses, and killed a power supply, but have been shocked or not had a fuse fail when it should have, or anything else along those lines and everything has worked fine.

However...

I was having a conversation with my tech from China about the controller display freaking out from time to time (it will just revert back to chinese, or half of screen will shit down and the other side stays where it is) and he said that it was caused by noise and if I grounded the machine (directly to the Earth) it would fix that. But I still haven't gotten around to it.

[Matt McCoy]

Hey guys! Well it's been a while since the original post but I never grounded the machine (other than it's normal ground thru the wall socket) Since then I've blow a few fuses, and killed a power supply, but have been shocked or not had a fuse fail when it should have, or anything else along those lines and everything has worked fine.

However...

I was having a conversation with my tech from China about the controller display freaking out from time to time (it will just revert back to chinese, or half of screen will shit down and the other side stays where it is) and he said that it was caused by noise and if I grounded the machine (directly to the Earth) it would fix that. But I still haven't gotten around to it.


That screen problem sounds pretty terrible. I don't think grounding will fix that. :)

[Bert Kemp]

My display pad does the same thing and my machine is grounded directly to earth.I think mine has a lose wire to the pad . some times if I tap the pad with my finger it straightens out, some times I have to reboot the laser. I can't seem to find the loose wire tho.

[Walt Langhans]

That screen problem sounds pretty terrible. I don't think grounding will fix that. :)

Meh.. not really. It only happens once ever couple months. I just turn the machine off and then back on and it's fixed. Just yet another chapter in the book "the fun of owning a chinese laser" :D

[Keith Winter]

Chinese stuff isn't built to the highest standards always like you pointed out a reset fixes it. Might just be a glitch in the software running the control panel.

[Bill George]

The Grounding bit has pretty much been driven into the ground (pun intended) The Chinese are pretty much clueless on US wiring standards and how they get UL approval is probably a matter of who gets the bribe. If I was guessing about your random LCD failures I would guess poor design and perhaps static electricity.

[Bert Kemp]

? Bill do you think magnets would have a effect on the display pad. I keep several stuck all over my machine. Never gave it a thought till just now.:rolleyes:

[David Somers]

Bert,

I use N52 Neodymium magnets all over my Chinese laser but as a rule, I don't keep any near the LCD display and keypad. I use them to hold things down on my honeycomb (steel with an aluminum frame) and to hold notes and tools on the frame and top (but not on the lid just because) FWIW. The effect of the magnets will fall off with distance.

I just ran out and looked. The nearest magnet to my display and pad are about 2 feet away.

[Dan Hintz]

? Bill do you think magnets would have a effect on the display pad. I keep several stuck all over my machine. Never gave it a thought till just now.:rolleyes:

Magnets, no... but poor grounding will easily cause display issues. Without a solid ground to work from, digital lines have a tough time knowing if they should be a zero or a one. Digital logic in general does not like a noisy ground, and plenty of bad behavior is easily traced to ground bounce.

[Bert Kemp]

Dave I've been using them for the same stuff ever since my first laser.

Dan my machine is grounded directly to an 8 ft copper ground rod

[Bill George]

Here is something to think about on ground rod driven vs main service ground. When I was in Ham radio I drove a 8 foot copper ground rod for it and so my long wire antenna would have a ground plane. Just for fun I used my Fluke ohm meter and measured between the green ground wire in the outlet box and my driven ground. There were several ohms difference and that is where the term ground loop comes into play. One can be a ground and the other can to, but between the two there can be a low voltage current flow and that can cause problems with electronics.

[Bert Kemp]

so you think I should unhook ground rod and just go with outlet grd



Here is something to think about on ground rod driven vs main service ground. When I was in Ham radio I drove a 8 foot copper ground rod for it and so my long wire antenna would have a ground plane. Just for fun I used my Fluke ohm meter and measured between the green ground wire in the outlet box and my driven ground. There were several ohms difference and that is where the term ground loop comes into play. One can be a ground and the other can to, but between the two there can be a low voltage current flow and that can cause problems with electronics.

[Bill George]

Are you 100% sure your outlets are grounded, if so that's all I have ever used. I do my own wiring so I know its done right.

[Dan Hintz]

Here is something to think about on ground rod driven vs main service ground. When I was in Ham radio I drove a 8 foot copper ground rod for it and so my long wire antenna would have a ground plane. Just for fun I used my Fluke ohm meter and measured between the green ground wire in the outlet box and my driven ground. There were several ohms difference and that is where the term ground loop comes into play. One can be a ground and the other can to, but between the two there can be a low voltage current flow and that can cause problems with electronics.

Absolutely, which is why in older threads I suggested against a separate ground rod if the outlet you have available has a grounding lug on it already. The only exception was Rodney's shop as he has (had?) a relatively screwed up electrical setup.

[Kev Williams]

Bert, as long as you're not grounded to both grounds, you should be fine--

For some of these goofy display and other such issues, I lean towards iffy connections as the problem. And for good reason, WAY too much experience with it!

In the past month I've had 2 machines go fubar on me-- first was the GCC laser. I thought I'd lost the power supply as it would start running a job but the laser wouldn't fire, then it would just stop. It would vector engrave fine, but not raster. And while this was going on, the display would fade away, then come back, until finally it was nearly blank. Yet when running troubleshooting tests, the display text was nice & black, and it every test passed...? I found a complete schematic for this machine online, complete with all required voltages and where to test for them. I tested everywhere, and all voltages were dead on...?

--yet the machine wouldn't work. At times it wouldn't even boot, only the motherboard would light up. But it WOULD boot up the test routines...

For lack of anything else to try, I unplugged every plug I COULD unplug, 2 or 3 times so the connectors would re-seat good.

When I was done, the machine fired up, and has acted like a brand new machine ever since...

Then last week, my V3400 cylinder machine lost the Z stepper, it started doing the 'can't figure out which way to go' thing while engraving a customers's stainless part. I called my Gravo rep and asked if he thought the stepper was bad or what, he said it sounded like a loose connection or broken wire. I traced the wires to their connector plug, which was pretty gunky after 20 years. I unplugged it, plugged it back in, and the stepper sprung back to life... From there I pulled every connector and cleaned them in and out with carb cleaner spray, and we're back to normal again...

Back in the '80's when everyone started buying computer controlled machines, I got a couple of calls from my competitors asking if I could help them as their machines were acting up. I'd bring in a can of Radio Shack electronics cleaner, unplug whatever connectors I could find on the machine and cleaned them up, and they worked fine afterwards. The original Concept 2000's had 24v power supplies, which would overheat half the IC chips on the mainboard. Every 6 months I had to pull the mainboard and clean the carbon off the pins of about 20 IC chips. What a pain that was. Used to blow many a voltage regulator transistor on the XYM boards too, I still have a bag of spares pinned to my wall. Fred Schwartz's upgrade kit for these machines was a godsend!

SO-- check your plugs! :)

[Julian Harrison]

I forgot to mention: I sleeved the trigger end with silicon and overlayed the Red Wire with a silicon tube. This prevents arcing.

[Bert Kemp]

Thanks Kev they are completely separate so I'll just leave be.