Grounding Dust Collector

Actually the bare wire that is inserted inside the PVC pipe is not there to ground anything, rather it is used to collect any static electricity that is created by the air and particles that by traveling along the pipe causing friction on the PVC.

As a demostration of this principle, get a sheet of paper, cut it in tiny small pieces, then grab a lenght of PVC pipe, 3/4” and a couple of feet long is ok. Now with a rag vigorously rub the pipe and pass it close to the pieces of paper. You will see that they stick to the pipe, the reason is that the static charge jumped from the pipe to the paper pieces. Also lightining is generated by the air moving through the clouds in a circular fashion, creating the static charge in the molecules of water vapour.

As the plastic is not a good electricity conductor it is no good to put the bare wire outside of the pipe either.

The static charges are colected by the wire inside the pipe and safely and continually discharged to ground so that no dangerously high voltages are generated inside the system.
Depending on the lenght of pipe. time the system is in operation and moisture content of the air, voltages could be generated in the hundreds of thousand and even millions of volts.
Again I must stress that this are static electricity charges. When they reach a sufficiently high level they could jump a spark and cause a fire.
Be safe….

Hello,

You may want to check out this link about PVC grounding. Presents some science behind the motivation for PVC grounding.

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

Grant

-- There's just something about the solitude and creation.....

I ran 6 gauge copper wire through my 4 in pvc DC. It eliminated most of the nasty ZAPS . Now I have all metal and have the entire system grounded to a 6’ grounding rod. No static at all now.

-- mike & judy western md. www. pvwoodcrafts.com pvwccf1@verizon.net

I agree with those above. I would use a bare wire and run it inside the pipe. If you have Ts or Ys or blastgates in your system, you can come out of the pipe at the T, Y, or gate and make an electrical connection with the other legs, then go back in to the next T or Y. Be sure your ground wire is attached to a machine ground at each leg, and to the collector ground.

-- Wayne - Plymouth MN

With all the talk and discussion on grounding PVC dust collection piping why not just eliminate the hassle and go with metal piping? If you are concerned, which I am as well, about static and PVC, abandon the idea and go to metal. I live in a very dry climate in the summertime and static is a major issue here. I am setting up a dc system and am going with metal pipe. I think its a better system overall and the worries of static, the “zaps” and the possibility of a fire are greatly reduced. I know that PVC is cheaper and some may argue easier to install, but the overall peace of mind knowing I wont have the higher risk of fire.

-- My job is to give my kids things to discuss with their therapist....medic20447@gmail.com

I got some flex hoses from a guy on craigslist – they were all ‘grounded’ with bare wire in them. I installed them only to find that all the chips get stuck on those internal wires, and kill the DC.

I took them out, and have been happy since. if you do have the option though – go all metal pipes.

-- ㊍ When in doubt - There is no doubt - Go the safer route.

Being thrifty is an OK thing in my book, why not strip the coating off of the wire.

Two birds… one stone.

-- My "Bench Dog"... her name is Sugie.

This subject was beaten almost to death during my years at Tauntons’ Knots, and the bottom line is that there are no known (i.e. documented) cases of a shop explosion resulting from an ungrounded DC system.

The most that grounding will do is prevent that annoying shock you might get when the humidity is low and a static charge builds up on the ducting. It’s annoying, but not dangerous.

-- Adversity doesn't build character...................it reveals it.

Something to consider: ESD (electrostatic discharge) is an arch enemy of computers and electronic devices, and is one of the major causes of device failures in the semiconductor industry.

If you are using computers in your shop, remote controls on dust collectors, or devices like the iSocket intelligent plug-in switch, you want to properly ground your equipment.

Sawkerf is right in that the sudden and momentary electric current is not generally dangerous to people, but it certainly can cause damage to electronic equipment. Don’t ask me how I learned this!

-- Gerry -- "I don't plan to ever really grow up ... I'm just going to learn how to act in public!"

Food for thought. If your bare wire is laying inside the pipe covered with sawdust, especially if it is lying in the bottom of the pipe I would argue it is probably insulated, and doing little good.

I wouldn’t bother grounding at all. This subject is much debated but I think it’s overkill. I have had my PVC system for about 4 years now and have never even received the slightest shock or spark.

-- Tony, Ohio

Grounding, Humm my dustcollector was grounded in my previous shop, when I moved it over to my new shop I did not re attach any of the grounds. I use 6” plastic pipe and have had no isses at all. My runs are very short however. I will be following this topic.

-- Ray

I stripped a 12 gauge solid wire and ran it through my system. Only static shocks I get are from my shop vac. Running your system moves the dust and chip through the pipes, if you have dust settled in the pipes and tubes that would insulate the wire, then you need a new system, yours is too weak to do any good. LOL

-- Carpenter assembles with hands, Designer builds with brains, Artist creates with heart!

I feel so stupid! I thought I could run the wire on the outside of the PVC and just connect the wire with screws through the wall of the pipe (extending slightly inside the pipe).

Can I ground the wire to ground wire of an adjacent outlet?

-- Chesapeake Bob, Southern Maryland

Bob,

Yes you can certainly do that.

As for all the comments above, I clearly stated that the conditions or layout of the system afect how much of a problem you could have. Again the factors are: Lenght of ducting (the longer a run the more effect), Time of operation of the DC (the longer it is running the more charge is accumulated), finally the atmospheric conditions of the site, (the lower the air humidity the more the static buildup)
While I have never heard that anybody has died of a static discharge you can still get a nasty burn.
Also why do I want to tempt fate if I can take simple and relatively inexpensive steps to mitigate this.
Also and finally I would recommend to place the wire so that it is not laying on the bottom of the duct, that is fairly easy to accomplish by drilling small holes at the beginning and end of each run and where the wire is coming out to be grounded and also to interconect with the next run.

Be safe.