RE: [CAD_CAM_EDM_DRO] Static electricity - WOW

>On large industrial machines we often ran a separate ground wire from the machine chassis directly to a grounding rod driven into the ground >thru a hole drilled in the concrete floor of the factory or shop.

Hopefully your bonding this to the main supply ground? Most earth ground driven inside of a factory are next to useless as the ground is too dry to provide a good ground at all.

>Many of the fires in woodworking factories start in the dust collection system from static sparks because of improper grounding or using PVC or >other polymer material in the dust collection tubing.

Urban legend as far as I have ever been able to find out. I have found no documented cases of the cause of a fire at a wood working plant being caused by a static discharge (but I would love to see it.). A grain mill would be much more likely and then it is from having just the right combination of flour dust to air, controlling the dust takes care of most of the problem.





Jeff Birt

Check out – Soigeneris.com…



From: CAD_CAM_EDM_DRO@yahoogroups.com [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of RANDY ABERNATHY
Sent: Monday, February 22, 2010 5:23 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] Static electricity - WOW





YES, the machine should have a ground run with the power line which is also connected to the machine chassis. On large industrial machines we often ran a separate ground wire from the machine chassis directly to a grounding rod driven into the ground thru a hole drilled in the concrete floor of the factory or shop.

Are you using PVC by any chance anywhere between your dust collector unit and the machine? If so, get rid of it and put metal pipe instead. If you are using a small portable dust collector or a shop vacuum with plastic head on it, you probably should ground the hose going to your machine.

One other thing you need to know is that wood dust can ignite and explode from even a small spark. Many of the fires in woodworking factories start in the dust collection system from static sparks because of improper grounding or using PVC or other polymer material in the dust collection tubing.

Hope this helps out.

Randy Abernathy
CNC and Industrial Machinery
service, repair, installation and
design

4626 Old Stilesboro Rd NW
Acworth, GA 30101
Fax: 770-974-5295
Phone: 678-982-0235
E-mail:
randyabernathy@... <mailto:randyabernathy%40bellsouth.net>

--- On Mon, 2/22/10, Jack <freshwatermodels@... <mailto:freshwatermodels%40yahoo.com> > wrote:

From: Jack <freshwatermodels@... <mailto:freshwatermodels%40yahoo.com> >
Subject: [CAD_CAM_EDM_DRO] Static electricity - WOW
To: CAD_CAM_EDM_DRO@yahoogroups.com <mailto:CAD_CAM_EDM_DRO%40yahoogroups.com>
Date: Monday, February 22, 2010, 2:32 PM



I guess I have a static electricity problem. While cutting a model boat
stand on my router I was using a dust collector . I was holding the
hose by hand. Something touched something else and both I and my
computer got a jolt of static electricity. Has anyone else run into
this? Cures???

I am assuming I need to ground the router which is aluminum on a wood
stand. Do I need to somehow ground the plastic hose on the dust
collector?

Any suggestions, insight, etc. appreciated! !!!!!!!!! !

jack

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