Dust collector grounding

[ljdm]

Searched the forum, read different opinions. Anybody test to see if the DC hose needs to be grounded at both ends, or just one? Some say both ends cause a ground loop, some say one end only, etc....

[knight_toolworks]

I grounded my shopbot dc hose to my metal pipe and with the same wire ran it to ground and it works great.

[Gary Campbell]

Lou..
There are always going to be varied opinions. Luckily this forum is never short of them. In the end you will have to take all those opinions and make your decision as to which way to go. Mine would be to ground one end away from the dust foot. As for the testing, we are all testing every day we cut on the Bot. I cant say for sure what works for anyone else, but I am pretty sure what doesnt work for us! Good Luck
Gary

[ljdm]

Guess I can always do the "shock" test, see which way gives the biggest or smallest jolt. Not the most scientific approach, but it will let me know if I eliminate the static charge. Of course, I'll post my definitive answer/opinion on which way it should be done.

[myxpykalix]

I grounded mine to the carriage, thru the DC hose and then to the housing of the DC. Now i noticed that the connection on my carrige has worked loose so it in effect is only grounded at the DC. So it in effect has worked ok in both scenerios. I can see how possibly the static could jump thru to the wire ribbing in the tube and go back to the carriage so i don't think it makes a difference.

So this makes me wonder, if static goes back to the carrige, then why prior to me not having any grounding did it cause the "shorts" in the system and now that static is still present and was grounded to the carriage do i not get those shorts?

[ed_lang]

Here is another way to look at this problem of where to ground.......

Would you rather have the discharge headed towards the control box with the electronics inside, or headed away from the control box?

IF you would like for the charge to go away from the control box, then ground the end of the hose that connects to the dust collector.

[butch]

Static electricity is everywhere and only causes a problem when it is allowed to build up. What you want to do is give the static electricity a quick and easy path to ground. The other thing to think about is to keep ALL the equipment on the same circuit the same ground potential. Thus if you ground both ends of the grounding wire to the equipment ground, which is in turn grounded to the earth ground, you keep all the equipment the same potential. Static electricity is normal and equipment can handle it until you allow the static electricity to build up and discharge. If one end is grounded, it gives the static a place to go, but if you ground both ends, you then keep your equipment at both ends the same potential, and static will not buildup. To understand static electricity, put on nylon socks and rub them on a carpet then touch the ear lobe of a 'friend'. The reaction of the 'friend' is to the static electricity being discharged to the point of least resistance. That is what happens in your equipment and especially the dust collection hose, where you have dry air passing over plastic. By running a wire around or through the hose you keep the static from building up. If you don't, then once the static electricity builds up to a point it can overcome the resistance blocking it, it discharges. If this happens to be your equipment, then it can travel through to the electronics and cause havoc, as it may be several thousand volts.
Also do not run your communications lines next to AC lines. It’s a different potential but you can get buildup much like a generator and cause communications data problems. And do not run communication lines next to florescent lighting as it can cause data problems also.

Because of experience and training I always do the following - ground both ends of grounding wires, run AC and communication wires in separate areas, with at least a foot between and stay away from florescent lighting. If AC and communication wires must run next to each other then do not run them in neat parallel lines but criss-cross the communications wire over the AC lines every foot or so. We had lots of problems with these problems in the field, and followed the above to prevent problems and fix random errors.
Hope this helps.

Butch