Static Electricity

[Humberman]

I have noticed that the static electricity generated by my planer is quite significant. I have tried wrapping the 4" duct tubing with copper wire and grounding it with a screw in the back of the planer. Doesn't seem to work. Any suggestions?

Cheers...Steve

[Mack C. in Brooklin ON]

I have noticed that the static electricity generated by my planer is quite significant. I have tried wrapping the 4" duct tubing with copper wire and grounding it with a screw in the back of the planer. Doesn't seem to work. Any suggestions?

Cheers...SteveHi Steve; Yup the other end has to be hooked to something like your cold water pipe to lead the static electricity away.

[Rod Sheridan]

Hi Steve, you have grounded the wire by connecting it to your planer, assuming that your planer is grounded. The problem is that the ground wire can only ground the static charge that is very close to the wire, leaving large areas of the hose ungrounded.

I had the same problem with my Hammer planer, I could receive a static shock from the outside of the plastic flex hose to my head. Very unsettling.

I replaced the plastic flex with a piece of aluminum flex, and now of course I don't have that problem as the aluminum is conductive, and my ductwork is grounded metal.

In your case if the planer is metal and grounded, the aluminum flex would be grounded even if your ductwork is plastic.

Regards, Rod.

[Bill Simpson]

Both mac and Rod are correct. It is not enough to send the charge back to the planer but also to sent it out the other end. attach that wile to both the planer for it's ground and the other end to the DC (assuming it is grounded) or to a waterpipe on the other end. A wilre attached at only one end is similar to an open circuit, muct be closed and allow the static to seek ground (other than jumping to the operator)

[Rod Sheridan]

Both mac and Rod are correct. It is not enough to send the charge back to the planer but also to sent it out the other end. attach that wile to both the planer for it's ground and the other end to the DC (assuming it is grounded) or to a waterpipe on the other end. A wilre attached at only one end is similar to an open circuit, muct be closed and allow the static to seek ground (other than jumping to the operator)

Actually Bill, that's not correct, if one end of the wire is grounded, grounding the other end makes no difference.

Either his planer isn't grounded, or the screw he used on the planer isn't grounded (screwed into a plastic part for example).

The issue is that you can't ground a non conductive object such as a plastic hose, they're called insulators because they resist the flow of electrons.

You need a conductive grounded hose to eliminate the problem....Which means aluminum flex would be the easiest solution.

Regards, Rod.

[Glenn at Raven]

I spiral-wrapped a copper wire around my flex duct and grounded it to my dust collector. No more static jolts!
Glenn

[Bill Simpson]

Actually Bill, that's not correct, if one end of the wire is grounded, grounding the other end makes no difference.

Either his planer isn't grounded, or the screw he used on the planer isn't grounded (screwed into a plastic part for example).

The issue is that you can't ground a non conductive object such as a plastic hose, they're called insulators because they resist the flow of electrons.

You need a conductive grounded hose to eliminate the problem....Which means aluminum flex would be the easiest solution.

Regards, Rod.

Rod, I didn't say ground both ends I said that both ends had to be connected, one to a grounded componant and the other to the machine, Perhaps I didn't state it clearly enough...

[hwgill]

I have PVC pipe, and I have the wire connected to screws which I put through the PVC every 12", then the wire is connected to the DC which is grounded...no problems.

[Lost in the Woods]

I not only ran the wire on the outside of the white PVC, I also ran it inside. Everything is grounded at both ends. Have never had a hint of a shock.

[hwgill]

I not only ran the wire on the outside of the white PVC, I also ran it inside. Everything is grounded at both ends. Have never had a hint of a shock.
I was talking to John at KMS about that, he suggested that you can run the wire inside the pipe as well, but if it breaks (which can happen quite easily if you suck up something too hard...I use a short piece for vacuuming purposes), you have lost your grounding, and it's a pain to fix. On the outside, with the screws sticking into the airflow, they pull up the static charge quite nicely, and it's easy to fix a break, or to extend the grounding as your DC system grows.

[Lost in the Woods]

I was talking to John at KMS about that, he suggested that you can run the wire inside the pipe as well, but if it breaks (which can happen quite easily if you suck up something too hard...I use a short piece for vacuuming purposes), you have lost your grounding, and it's a pain to fix. On the outside, with the screws sticking into the airflow, they pull up the static charge quite nicely, and it's easy to fix a break, or to extend the grounding as your DC system grows.

And I thought of that as well, so I took a slightly unconventional route, or so I think, from when I did it 5 years ago or so.

I didn't bother with any wire where Y's and T's were, I only did the straight runs/lengths. I drilled a very small hole near where the PVC would end and the joint would be covering the butt end of the straight pipe fitting into it, and another one at the opposite end of the straight pipe. Then I ran the bare copper multistrand wire straight inside the pipe with both ends coming out of the drilled holes respectively. Rather than just simply connect the two ends in a straight line, I ran the wire around the pipe at about a 45 degree angle, and then twisted them together using pliers. I then used a twisty electrical cap now to connect those bare twisted wires to sheathed copper wire and would have that connect in the same fashion to the next straight segment. Ultimately, the series is grounded on one end to my DC housing, and the other end to the casing/housing of the various machinery.

I had thought that over the years the wire could loosen, and that I would either have to try to arrest that by either pull ties on the exterior of the piping over top of where the wire ran, or simply with duct tape (duct tape being the least desirable due to its kinda ugly look and crappy residue if and whenever I would need to remove, as they do dry out over time). But I've never needed to do either. The wire has stayed relatively "put". It probably helps a lot that all the PVC piping is fairly securely fastened everywhere and doesn't get jostled around or banged into. I mean the only real thing that can bang up on the wire is the debris flying thru the inside of the pipe, and since it is only coming into contact thru the straight sections and is flying in the same direction of the wire's orientation, obviously this has worked out fine.

All the piping with wire running in it, is orientated so that the wire inside is on the ceiling, in other words, not where it would sit at the bottom and be apt to collect debris gradually over time. The wire kit I used, that came with the perfect size drill bit for running the wire in and out of the pipe walls was the LV kit (http://www.leevalley.com/wood/page.aspx?c=1&p=62616&cat=1,42401,62597). The sheathed wire was wire I had on hand sitting around for decades waiting to be used.

The reason I did all this, was to avert the static causing a catastrophic explosion, which late I found out to be false information. Nevertheless, it does help avoid getting zapped, and by the sounds of, it was worth it at the end of the day for that reason alone.:frown:

One nice thing about this setup, is if I ever did have a clog or something stuck in the line, it's not as much of a task getting to it and dealing with it. I really liked how PVC and their fittings fit so nice and snug together. Except at a few locations where there is an issue with keeping the LV self-cleaning blast gates (http://www.leevalley.com/wood/page.aspx?c=1&p=51506&cat=1,42401,62597) snugged to another component, I've used no caulk anywhere, and get terrific suction.

If I had to do this all over again, and I was willing to spend 25 to 50% more on the piping, I would have gone with spiral metal ducting. Probably just as fast to install, but because I had never done it before, I was terrified of getting stuck with components that I couldn't return as you had to deal with wholesalers for that stuff, and not the friendly folks at the returns desk at HD. I went and bought about 4 fold what I ultimately used, using trial and error, fly by the seat of my pants approach to putting it all together, returning the parts for refund I didn't need.

[asindero]

Statics are caused by dry air. I worked in a woodworking plant with automatic mist sprayer. Our project there was a huge dust collector. Aside from srayers everywhere, there were sprayers inside the duct which is 3 feet in diameter.

Static can cause fires. Grounding isn't enough.

[Bryan @ Woodstock]

I get shocks off my 25" drum sander with two 4" plastic hoses. Get too close when taking stock off the back of the sander and your head gets a lot of tiny jabs from the little lightning bolts. Very annoying!!:shock: Someday I am going to buy the LV 4" DC hose with the metal spiral wire, but it's way down on the Wish List!

[Don Burch]

Static build up in PVC ducting discharges point specific ie if you ground point A, point B that is 1 mm away can still be fully charged.

http://home.comcast.net/~rodec/woodworking/articles/DC_myths.html

Unless the duct is fully sheathe in metal, there will always be some static build up.

According to he research, it is an annoyance, but not really a hazard.

Don

[asindero]

According to he research, it is an annoyance, but not really a hazard.

Are you gonna wait untill you get a heart attack before those smart guys say they made a mistake?
Have you seen a spark 2" long? How big is the gap in your car spark plugs that start internal combustion that make enough power? A rich mixture is what needed to start a fire.

Static electricity is not just annoyance. How do you stop a burning pile of sawdust?

[Don Burch]

Are you gonna wait untill you get a heart attack before those smart guys say they made a mistake?
Have you seen a spark 2" long? How big is the gap in your car spark plugs that start internal combustion that make enough power? A rich mixture is what needed to start a fire.

Static electricity is not just annoyance. How do you stop a burning pile of sawdust?

The point I was trying to share was that grounding plastic ducting only grounds one specific point not the entire line. This was a concern which started this discussion.

Take a run at Dr Cole not me! The research is published, anyone who can read can make their own decision. Check with your own insurance company regarding the risk.

I believe also that an internal combustion engine is designed to create an explosion. I do not believe anyone has intentionally designed a dust collection system to do the same.
From my own experience vacuuming up waste in the shop using only a piece of 4" flex hose, I frequently experience significant arcing to grounded metal.
But no fires, not even the smell of anything burning.
How many fires have your 2" sparks started?

If you would read Dr. Cole's article, you would then understand why grounding PVC or similar ducting is difficult, and that the conditions for combustion seldom occur.

And for heart attacks, well that is another forum somewhere else.

Don