Shop Vac

[ken_from_oz]

Can you run a shop vac directly to the dust hose of the shopbot attachment, if so how do you ground a shop vac?

[fleinbach]

The main thing you need to ground is the vacuum hose. There are many articles written about this plus I believe a search of this forum will produce information on grounding. There are 2 methods I am aware of for grounding the hose. 1. If it's the common plastic hose you need to run a ground wire through the hose. 2. Some hoses use spring steel for support. You can tap into and use it for your ground.

[rustnrot]

Why the grounding of the hose, to help prevent electrical noise, make for better dust collection, standard practice for dust collection systems, or all of the above?

[billp]

One major reason is to help in the prevention of static electricity which in a very dusty environment can lead to a "grain silo" type of explosion.....All of the rest of the above reasons are valid as well...

[fleinbach]

Until I grounded my Hose right in the middle of a cut file the tool would just stop. I would clear and rest and it would either finish the file or stop again at some other location. I have not once had a file stop running since I grounded the hose.

[ken_from_oz]

I read about the grounding of the shopvac hose but where does the copper wire go after it goes through the hose and into the bucket of the shopvac? my shop vac does'nt have a ground any where that I can see inside.
any help
Ken

[paco]

Ken,
install one...

[ken_from_oz]

Paco, if I new what to do I would have done it, you are obviously more advanced in this area than I, but I am sure that there is a lot of areas that I am more advanced than you, I am not searching for smart arse replies I am searching for step by step instructions because I am a learner of this subject not a teacher. Which reminds me of some of the teachers at school who could'nt understand what "teach" meant.
Ken

[mikejohn]

Ken
A better response would have been
"I don't know how to install one, can anyone give me assistance", not some down-under straight talking which some may take for uncalled for rudeness.
An earlier post of yours indicated a certain unreasonableness, blaming all around, and the machine, when the problem lay closer at home.
People go to great lengths here to assist other ShopBotters, paticularly our 'sometimes English challenged
' Canadian. Take advantage of it, by try and stay civil.
.........Mike

[fleinbach]

Ken

It was late and Paco was kidding. That's what a smiley face indicates. After he get's some sleep I am sure he would have answered your question with more detail then you would need.

Drill a hole in the bucket and attach the ground wire to it. Then run another wire from there to some ground. Since your vacuum will be close to the shopbot you can attach it to any grounded part. Or you can attach the ground wire to the shopbot on the Y carrage.(I presume you grounded the shopbot as instructed in the manuel.) You will need to poke a hole in the hose to bring the ground wire out for attachment in this case.

Maybe this will help
http://www.durovac.com/industrial-vacuum/hose-tools-attachments/vacuum-cleaner-hose.htm

[weslambe]

Ken,

I understand your angst. Here's what I did to help out with the dust static. I grounded my Y car. I took an old extension cord and ran it across the plastic arch that holds the wiring and connected one of the bare wires to one of the bolts on the y car. I took the other end and connected the wire to the main ground block for my shop. This seems to have worked for me.
make sure you cut off the plugs so that you are never tempted to plug it it!

My table is grounded and my y car is grounded. I could have grounded the x and z also, but I haven't had any issues since doing this.

Don't try to install a ground on your shopvac.

[paco]

Hi Ken!
I was assuming that, since you were into installing a ground, that you understand it's purpose and function... so I thought you only need to know that it was normal for the "Vac" to not have a ground already in place for this kind of use and so that you need to install one to continue the grounding path through the barrel...
I did it exactly as Frank suggest execpt that the hole was readily there for an handle and that I connected it right to the control box (was closer). Once install; test it...

Hello Wes!
Curious; why not to ground a "Vac"?

[mikejohn]

Paco
I assume the shopvac is double insulated, requiring no 'ground' (in fact, having only live (hot) and neutral wires connected, no earth or ground). Therefore maybe introducing an earthing (ground) wire may well negate the double insulation safety.
...........Mike

[weslambe]

Paco,

For the reasons that Mike mentioned. It's best not to fool around with U/L stuff unless you are a certified electrician. Besides, it's not necessary. All that you are looking to do is bleed the charge to ground and that can be done the way that I did it. You could run a bare copper wire across your vac hose to ground if you wanted to.

I just chose to go the way of least resistance, that's all.

Wes

[paco]

Hummm...
so you guys are saying that a "Shop Vac" is already grounded to prevent fire in it's barrel from electrical spark to could be from the hose?

PS: I might have omit that when I suggest to install a ground on the "Vac", I only suggest to continue the path of the bare copper wire from the inside of the barrel to it's outside; not to modify the electrical set installation of the "Vac" itself...

[mikejohn]

Paco,
No, just the opposite.
The electrics are double insulated, preventing anything live (or hot) coming into contact with the operator via the casing. So any static has nowhere to go, via the machine.
As you and Wes have said, simply take the copper wire through the tube wall and ground (earth) it somewhere convenient.
........Mike

[fleinbach]

There are 2 reasons for grounding the vacuum hose. Both are for the removal of static electricity.

The first reason as we have all heard is for safety. It has been well documented that the proper mixture of sawdust and air ignited by a static spark can and has caused an explosion and fire.

The second reason is to prevent a static spark from getting into the electronic circuits causing all sorts of problems. Years ago a static spark would destroy an electronic circuit board. Most Electronic circuits today have built in protection against static discharges, but many still don't. And as I stated earlier it will interrupt a data stream.

As for my suggestion of running drilling a hole in the canister to facilitate bringing the ground wire out for connection. I could not see how this would misslead anyone into fooling with the electronics. The canister is no where near the motor on any shopvac I have ever seen.

Being double insulated is to protect the end user from electrocution. It in no way has anything to do with preventing static electricity.

[ken_from_oz]

Sorry about the uncalled for rudeness Mike and Paco but I thought that my question about what to do with the wire was pretty straight forward and the reply from Paco seemed a bit abrupt, not really a helping answer.
Wes's answer was the explanitory one that I was after (thanks Wes).
Mike, the earlier post that you speak of was even a brain teaser for Ted Hall and I was relieved in the end that I was not at fault and that I had followed all of the setup correctly.( the fault was in the setup of the control box or the distance it had to travel during frieght)
I am very appreciative of this forum and from now on I will keep my down-under straight talk to myself and only reply to sensible answers.
When I here talk of explosion and fire I like to do everything right and make sure that the machine is safe for myself and other people around me.
Ken

[mikejohn]

Ken
I spent seven years down under, and understand how Australians talk, and realise its not meant to be offensive. (I am, after all a Pommy B******)
But the guys from the other colony to the west are sensitive souls, and sometimes don't understand.
Now your up and running, tell us how its going. The good stuff.
.............Mike

[Mayo]

Before running a ground wire on my shop vac, I was getting weird intermittant noises from one or more of the stepper motors. I figured the static was bleeding into one of the motor wires which was bundled against or near the shopvac hose, over the arch. I ran a bare wire through the vac hose, into the cannister and attached it to a screw which was screwed into the metal housing of the motor. This eliminated my problem.

Another potential for causing fire happened to me:
Imagine your shopvac or dust pick-up working while you are cutting MDF or any wood, and then the piece it's cutting gets jammed against the bit and the table, and starts to glow red hot. Quickly you shut off the router but the shopvac is still pulling air (and glowing embers) into the cannister! About 5 minutes later there's smoke billowing from the shopvac! Opening up the cannister, I see a bright red glow in the MDF - which I had to use a garden hose to extinguish after carrying the smoking mess outside.

Always look inside your dust pick up container if your bit gets stuck and starts things glowing.

[mikejohn]

Mayo
Attaching any wire to a metal part of any double insulated piece of equipment doesn't ground that wire, in the way you describe. The metal parts of your Shopvac have no ground. If your motor develops a shorting problem, your copper wire will become live (hot).
We need someone who really understands electrics to step in here. We need a definitive answer to this dangerous (I mean dangerous wiring) problem. I don't know enough to give this information.
...........Mike

[gerald_d]

Mike, if the metal casing becomes live due to a fault condition, then some copper wire is not going to make the hazard worse.

If your dust collectors/shopvacs don't have a ground/earth connection, then I would think to ground the copper wire to the ShopBot end only. I would only ground one end of the wire.

[mikejohn]

Gerald
I have assumed all through this thread that a shopvac has a double insulated plastic casing.
If the machine is double insulated, then there is,by definition, no metal connection to the outside. If you now connect to the metal inside with a wire coming from outside, surely you do now have a metal part that you can touch that can become live(hot)?
.........Mike

[gerald_d]

Okay, I will agree with you that one must not, under any circumstances, dig down under covers until you find metal. That would be plain stupid dangerous. I assume that when guys say they have attached the wire to "the metal housing" that they mean something that is externally exposed. Double insulated is not restricted to all plastic.

If the power lead to the ShopVac does not have a ground/earth wire then you won't find a grounding point at your ShopVac.

[mikejohn]

Gerald
In this area I am definately not anything like knowledgable.
If any electric tool has a metal body, doesn't it have to be earthed (grounded)?
........Mike

[fleinbach]

Mike

"If any electric tool has a metal body, doesn't it have to be earthed (grounded)? "


No, it can still have a double insulated motor housing


Gerald

"If the power lead to the ShopVac does not have a ground/earth wire then you won't find a grounding point at your ShopVac."

You are correct The shopvac Mayo describes most certainly was not a double insulated one but has a grounded plug I'm sure. Because if it did not have a ground plug it would not have cured his problem.

Double insulated tools are constructed so that no failure of any electrical componante carrying current internaly can accidentaly make conntact with any external metal. This prevents the end user from a shock or worse. If a shopvac has a metal canister and the power cord does not have a ground pin you can be sure the motor housing is double insulated. If this is the case after running your ground wire you will need to run another wire from the case to some ground point.

[gerald_d]

Mike, I have portable drills that are double insulated, but they have metal chucks - are your chucks made of plastic? Or are you taught to wear rubber gloves (and cricket box) when changing the bit?


PS did you get a lengthy (3.4MB)zipped mail from me today?

[mikejohn]

Gerald
I just checked a Bosch drill.
It has only two wires.
The drive gears at the chuck appear to be plastic of some sort.
The chuck is metal.
I think any cricket reference might well force us to seek a return to the unpleasentness of 1899-1902

.........Mike

[weslambe]

I forgot the other thing that I did to help with the static on my dust collection system. I grounded the metal frame of my Delta dust collector back to the shopbot via copper wire. I have a Delta 1.5 hp system that has a double? insulated motor but the rest of the system is metal (outside of bags and hose). Since my Shopbot is grounded with some very thick single strand copper wire any static will seek the path of least resistance to ground.


The reason I hooked mine up was that I was tired of getting the poop shocked out of me after making cuts on the bot. After doing this, no more shocks.

wes

[normand]

One can change the two wire cord of the shopvac and put in a three wire one and ground from there

[mikejohn]

Have a look here (http://www.electrostatics.com).
I didn't realise the problem was so complex. In particular, read the bit about grounding being insufficient. However,it is the site of a manufacturer trying to solve your static problems with his product so 'caveat emptor' as they say.
...........Mike

[merln]

Ken,
Years ago my daughter had a dog that liked to chew on cords. One day the dog chewed my shopvac cord off leaving me a cord about 4 feet long. Since the cord was now too short to do me any good, I took my vacuum apart, removed the cord and went to my local big box hardware store to find a new cord. They carry lots of 3 wire cords that are cheap and ready to go but no 2 wire cords. Which meant if I wanted a 2 wire cord, I had to make it. With the 2 wire, I had to buy the wire and a plug and put it together and put up with the lip service from the help telling me how to do it. With a 3 wire pre-made cord, I just cut off the female end, peel the cover and hookup. So, the choice was a 3 wire cord at half the money and no lip service or... So, I attached the black to the black and the white to the white just like it was made at the factory. The ground wire I put under a screw that held the two plastic sections of the case together and was away from the motor and any other electrical or metal compontents. My "double insulation" was not compromised and my static went away. My new "Bigger" vac has a two wire cord on it and when I use it on the bot, I get the poop shocked out of me too. Its next for a cord transformation and the leftover 4 foot cord I gave to the dog to finish off. She never chewed on a cord again.