Help ! Major static !

[hiwa]

Thanks fellas. What a wealth of information. It is really dry and humid here in Alberta, and I think that aggravates the static issue. I tried tying a bare wire on my arm and to the body of the machine ( I am insulated from the ground ) , and it seems to be working,although inconvienient.

 

[THG]

The only thing about grounding yourself to the machine body is that you will build charge and get zapped when you touch something else! Unless you're barefoot on cement, in which case the charge will pass from the machine's body to your body to the ground.

Unless we already covered that? I don't remember

 

[gary jp4]

The only thing about grounding yourself to the machine body is that you will build charge and get zapped when you touch something else! Unless you're barefoot on cement, in which case the charge will pass from the machine's body to your body to the ground.

Unless we already covered that? I don't remember

Normaly, that is not a true.

If you are connected to the machine then your body, the machine, and the cement all have the same potential (are all grounded).

Your statement is only true in rare exceptions of the machine not being grounded properly, as covered earlier in this thread. If you are connected to your machine and getting a static shock (spark) when touching other things around you then you need to check your machine ground.

Some machine ground issues that would allow this to happen are:

The ground wire is unattached or broken internally in the machine.
The ground prong has been removed in which case it would be unattached at the plug.
The ground wire is unattached, unconnected, non-existent or broken in the building wiring.

In all those cases you are also at risk for a line voltage shock. To get a line voltage shock, in one of those situations, your machine would have to get a leak from the wiring, switch, or motor to the case (frame). Then, since you are connected to the machine, you would have to touch something around you that was grounded. Then you would get fried.

If you are connecting yourself to the machine and getting static shocks when touching other things around you, this is serious and you need to get it fixed.

Gary

 

[James_Terrio]

I think Gary's right. You really shouldn't be getting zapped unless there's a problem in your machine or the wiring in the shop. Certainly not at 60-70% humidity.

I used to make part of my living playing guitar and singing in bars. I assure you, there's nothing more distracting than getting kicked in the mouth with a big ZAP every time your lips touch the mike, due to improper grounding.

If the wiring in the building is faulty, there's not much you can do about it except to hire a qualified electrician and get things up to code. Doesn't matter what you're wearing or standing on.

 

[gary jp4]

I think Gary's right.

Thank You

You really shouldn't be getting zapped unless there's a problem in your machine or the wiring in the shop. Certainly not at 60-70% humidity.

Agreed, we are talking about static again here (not line voltage) and given that you are connected to the machine.

I used to make part of my living playing guitar and singing in bars. I assure you, there's nothing more distracting than getting kicked in the mouth with a big ZAP every time your lips touch the mike, due to improper grounding.

Ouch

If the wiring in the building is faulty, there's not much you can do about it except to hire a qualified electrician and get things up to code.

Doesn't matter what you're wearing or standing on.

What we have been talking about in this thread are the exceptions, not the norm. Usualy when you get shocked by line voltage it is an exception.

If you are connected to the machine, and if the machine is not grounded, and if the machine gets a line voltage charge, or leak to the case.

Given all that then,

if you touch something that is grounded you will get shocked because you just made a path from the charged object (the machine) through you to ground. If that object is a concrete floor and you are wearing insulating rubber shoes, are not wet, or are standing on an insulating mat you still wont get shocked.

So it does matter what you are wearing or standing on.

However, given all the conditions above, if you touch something grounded with your hands or other part of your body you will still get shocked.



One of the points was that if you are connected to the machine and getting shocked by static when touching other things that are grounded then their is a ground issue with your machine / wiring.

Gary

 

[Jason B.]

if you touch something that is grounded you will get shocked because you just made a path from the charged object (the machine) through you to ground. If that object is a concrete floor and you are wearing insulating rubber shoes, are not wet, or are standing on an insulating mat you still wont get shocked.

This statment is only half true, True if you are touching ground then touch the object you will get shocked but if you are touching the object then touch ground you will not. Standing on a rubber mat or wearing shoes will make you more of a target for getting static shock because the shock is building on your body and not the machine. Remember we are talking about static shock here, the static does not build up on the machine. like I said before if you take off your shoes or ground yourself you will dissipate the charge as it happens, the shock is not going from the machine to you its going from you to the machine because the machine has a greater ground.

 

[gary jp4]

Granted, it is getting pretty complicated with all the scenarios, but you didn't read them. I think you and I understand the issues just fine but this is confusing for those posting incorrect conditions.

This statement is only half true, True if you are touching ground then touch the object you will get shocked but if you are touching the object then touch ground you will not.

No, you didn't read the prerequisites. In the last case (and the last several posts) you are already connected to the machine. That is what I and the previous two posters have been talking about.

Standing on a rubber mat or wearing shoes will make you more of a target for getting static shock because the shock is building on your body and not the machine.

Again, not if you are connected to the machine as stated, unless the machine is not grounded, also as stated.

Remember we are talking about static shock here,

No, we have been talking about both, line voltage and static separately. The thread has turned to talking about both static and line voltage separately because of the implications of grounding you body to the machine or separately to ground and the associated line voltage shock risks. In this case though (the quoted sentence), I was specifically talking about line voltage as stated earlier in the sentence or the one before it.

the static does not build up on the machine. like I said before if you take off your shoes or ground yourself you will dissipate the charge as it happens, the shock is not going from the machine to you its going from you to the machine because the machine has a greater ground.

That is what I said in post 7.

Gary

 

[Jason B.]

Guess I missed that gets hard to keep track.

But consertrating on the OP's original statment it seems to rule out electric fault though it is electricity so who knows. Reading post #7 I see that you say ground is + How do you come to this conclusion?

 

[gary jp4]

Guess I missed that gets hard to keep track.

But consertrating on the OP's original statment it seems to rule out electric fault though it is electricity so who knows.

Hello Knifenut1013, we got off on the line voltage shock potential in relation to grounding your body to the machine, or to a separately ground , in order to prevent static shocks. Then THG said he was getting static shocks while he was bonded to the machine and touching other things. This would indicate to me that the machine was not grounded properly because the other things in the room should be pretty close to the same potential as ground, so I would say he and the machine are not grounded.

Reading post #7 I see that you say ground is + How do you come to this conclusion?

Good question. I don't know. Maybe somebody slipped me drugs or I had a heat stroke. That's wrong, or at least oversimplified. Some messed up wrong thought process along the lines of the old idea of electrons flowing form negative to positive so they were named wrong and also my Van de Graph generator as a kid having the lower electrode at the bottom of the belt connected to ground I guess, but that is probably wrong too. I will edit and re-word it in post #7. With all the dissenting statements in this thread I am surprised no one else caught that. Good catch.

Ground is a relative term in the case of the 120v AC line voltage part of this discussion and hopefully is the same as common or 0 volts in relation to the hot wire. The hot wire is alternating from 170v + and - for a RMS of 120v. Electrons don't necessarily flow. Atoms do flow? Protons are involved, current flows both ways (atoms), etc.

Still, all that has been said applies and if you make a path through your body between the hot wire and ground you get shocked.

For the the static part of the discussion ground (earth) is also relative it appears. It changes from + to - in relation to the clouds causing different kinds of cloud to ground lightning so I guess I should stay out of the + / - terms and stick to terms like common, and relative.

Excerpt from http://www.weather-plus.net/LightningDetector.html

Cloud-to-ground lightning is the most spectacular lightning. It is the lightning bolt we see reaching from the sky to the ground forming a bright, usually forked bolt of light. The ground is the most conductive object that will release the most energy. This form usually occurs from the base of a negatively charged cloud. Sometimes there is a rarer form that happens from the the positive charge in the top of the cloud to the negative charge on the ground known as a positive flash. Only about 20 percent of all lightning reaches the ground. Over the entire Earth there are over 100 strikes every second.

Cloud-to-ground lightning is the most damaging and dangerous form of lightning. The great majority of ground flashes are negative, but the most powerful and most dangerous are the positive ground flashes that can also produce sprites in the mesosphere. Positive flashes occur in the decaying phases of large thunderstorms and in the very active stages of severe storms. Most cloud-to-ground lightning strikes come from the negatively charged bottom of the cloud traveling to the positively charged ground below.

Gary

 

[Jason B.]

How old is that lightning strike quote? Recent high speed video has changed a lot of what was thought to be known before.