Grounding

[Gene Uselman]

I don't think you can overground any high voltage equipment. If you can ground to the ground buss in your breaker box it would be good, normally metal water pipes are good grounds, or I have pounded a copper coated ground rod [from a DIY center] into the earth near by. Gene

[Anders Troberg]

Ground prong is sufficient, PROVIDED that it's properly connected inside the machine (ground pring securely connected to the metal chassis).

If the ground prong in the house isn't good enough, you've got a bigger problem that you need to call an electrician for immediately...

Adding a separate ground can be a security risk in itself. If you do it wrong, the cable slips (say, for example, if you manage to yank it with the vacuum cleaner) and gets in contact with something hot, someone could die.

So, check that the machine is electrically sound (proper connections, neat and tidy inside, ground connected to chassis), and that's all you need.

[Gene Uselman]

Ground prong is sufficient, PROVIDED that it's properly connected inside the machine (ground pring securely connected to the metal chassis).

If the ground prong in the house isn't good enough, you've got a bigger problem that you need to call an electrician for immediately...

Adding a separate ground can be a security risk in itself. If you do it wrong, the cable slips (say, for example, if you manage to yank it with the vacuum cleaner) and gets in contact with something hot, someone could die.

So, check that the machine is electrically sound (proper connections, neat and tidy inside, ground connected to chassis), and that's all you need.

I don't think a separate ground can actually be a bad thing- that is stretching the point a bit. I still contend that as most people aren't well versed in electrical knowledge, and we know the wiring of these machines can be pretty wonky, and our 115V system is way different from the 'normal' 220V system. Make sure the machine case is grounded, it cannot be a bad thing.

[Anders Troberg]

Assuming the extra grounding is correctly made, it's not a problem.

However, if it's wrongly made, for example so that it can come loose, it could be a problem.

As it's not really needed, I would recommend against it. I would recommend against it especially to someone who asks how to do it, as they are more likely to do it wrong.

[Gene Uselman]

Anders- a ground is a ground and is a good thing. If you have live wires where the ground wire can hit them... the problem is not the Ground wire.

[Jeffrey Aley]

I think there are a couple of things that an owner of a new laser should do (in regards to grounding). (Note: electrical "ground" in the USA is termed "earth" in many other countries).

First, ensure that the chassis of the laser is actually connected to the ground wire. How do you do this? Unplug the laser. Use an ohmmeter to measure the resistance (in ohms) between the ground pin on the power cord and the chassis of the laser. Measure a few points. You should have less than 5 ohms. If not, trace where the ground wire goes into the machine. Usually it's connected to a lug screwed into the frame. And sometimes the manufacturer powder-coats the machine BEFORE adding the lug, thereby insulating it (bad!). Use some sandpaper to remove the powder coating so that the lug contacts the bare metal of the frame. Then re-test.

Second, you need to be sure that the ground prong on your electrical outlet is truly connected to ground. This can be much trickier, and probably requires the services of an electrician. My personal opinion: if your laser is in a properly-wired location, in a country where wiring is usually properly inspected, then you're probably fine. For example, I live in a newer home in California. I believe the wiring is fine. On the other hand, some of us are in older garages that have been wired haphazardly by a previous owner, or we may live in a country where electrical wiring is often substandard. In those cases, I'd hire someone to install a proper ground - to be sure.

There *is* such a thing as "too much ground". If there are multiple paths to ground, the tiny resistance differences in those paths can cause "ground loops". Not a problem from a safety perspective. But they can cause very weird behavior with electronics.