Electrosctatic Phenomena

Please describe the phenomena.

Please describe the machines.

Please detail the material flowing through the machines.

Please describe the earthing arrangments for these machines and why they differ.

Please help the forum to provide the requested help.

Please ground/earth all exposed conductive parts. (Just a decent earth connection to the main frame will probably do the job).

If everything else is identical, it could be as simple as the humidity level. With room #2 being much dryer than room #1.

I have no idea why having the machine stopped would make any difference.

Don't stop machine 2.

Check the flooring. Check all the grounds ^{(not coffee)}. Control the humidity.

You're there, we're not. Find out what's different about the two installations.

The door? The table?

Another thing to look at is the possibility of the personnel themselves somehow picking up a static charge before entering the room. See what happens if you ground the humans before they enter the room.

Good thinking.

This phenomena occurs only when the machine is stopped .and all metallic parts in the room are charged .

It is à compressed machine ( convert the powder on compressed tablet )

We know that the powder is electrically charged ;but why the phenomena occurs only for one machine

I would check for a voltage reading with a multimeter from metal surfaces to grnd and any common or bonded circuits..If you get line voltage reading then, sounds like you have a partial short....Check continuity to ground, isolate section by section...Could be in switch...If you get only static voltage, then would agree with grounding workers entering room...

The room door is also charged

The stainless table (isolate from machine ) in the corner is also charged

All metallic parts in the area are charged

Thanks

It's possible that the floor coatings are different.ie; 1 painted, 1 tile..

http://www.envirosafetyproducts.com/2-3-diamond-stat-826-floor-mat.html

We start by inspecting the both installation ,the ground ;the phases ,amperes, voltage .everything is the same and normal .

Thank you

"We start by inspecting the both installation ,the ground ;the phases ,amperes, voltage .everything is the same and normal ."

No everything is not the same. You have simply not discovered the disparity.

Is the shut-down switch on one machine perhaps disconnecting a neutral?

" but that ground may not be reliably bonded to the complete facility electrical system's ground."

This, to me, sounds like a very plausible explanation...

As has been suggested earlier the room with the electrostatic problem may have a drier atmosphere, not allowing the static buildup to self discharge safely.

One thing which may help is to install an air ioniser in the room with the static problem. This approach is used in electronics manufacturing in addition to static dissipative surfaces to bleed any static build up to ground so that static sensitive devices are not damaged.

As has also been mentioned, something about your process is generating the static in the first place. if you can identify that, and you should be able to do so, you have an opportunity to largely quench the static at the source.

The humidity value for both area is 30%(mor or less 5%)

Thanks

Need to ask one question. Do you see an arch to your person as you almost touch the metal, or do you only get shocked when you make contact? If you are seeing an arch it is static electricity. If your getting shocked only when you touch the metal, transit voltage. Need to define which we are talking about.

As far as neutrals being disconnected, I have seen 4 pole MCR's with the grounds wired into one of the contact Poles. Thus no ground on machine when "E" stop was hit. You have to assume anything is possible until proven otherwise.

We shocked when make contact ,that's right .

If it is ;transit voltage the question is what about the second area ?

Thanks

As others have said it is really hard to guess with so little information. It may not be static build up at all, it could be leakage current due to a faulty piece of equipment and insufficient earthing or earth leakage monitoring (ie- potentially lethal).

I would also suggest looking at the building earthing (which may be the culprit).

Let us know what you find please (as well as what country you are in).

What type of floor do you have in each room? (just guessing, site unseen)

And..."everything" is obviously not right and the two installations can't possibly be the same.(not guessing)

What is your location?

The floor ( booth area ) is GMPs approval (resin ) .We are in Morocco.

Thanks

GMP = Grand Master Poobah??

Good guess!!!

Good Manufacturing Practice

Yeh right!!!

You first need to determine whether you have an electrostatic or an electrical energy reticulation and management problem.

Once you know what the problems are the solutions are also spelled out in GMP.

If the electrical discharge is dissipated (gone) once the machine has been touched, then it is just a static buildup. If the electrical discharges is always present, not being dissipated once grounded, then your problem is excess electrical current leakage. That machine or a component of it has some defects or some deterioration in its isolation has developed? Measure safe allowable leakage current for each and compare.. Good luck!

What about area doors ( 2 doors ) ;one for access and the second for exit ?.And what about the stainless steel table (for apparatus ) ?. The table is located around 1m from machine without contact .

Thank you

Is the stainless steel table grounded? Is the door frame grounded?

Are there any electrical appliances on the table or leaning against the door frame?

You may have two problems, one is a high leakage current in your machine which probably is due to a poorly grounding system, and also the build up of static electricity. Provide a redundant fixed grounding system directly tied or bonded to your power source and The cheapest most economical way to resolve the static issues is to control the humidity level in that equipment room.

Once the machine ( or table or doors etc )has been touched the discharge disipate immediatly .

Thank you

Are you & Anonymous Poster #1 the same person? If so why hide behind the anonymous Poster???

Yes ,the same . According to my first experience with the system ( it's my first question in this good team ) ;and it's a gaffe !

Thanks

Install "electrostatic flooring" (ie conductive tiling system) bond the whole lot and make sure the grounding system is correctly designed, implemented and integrated into your facility.

Audit, and ameliorate as required, all legacy electrical and grounding systems.

First off I would not say the machines are the same. They may do the same work and produce the same results but I would ASSUME that the power to them is fed by different circuits.

Go to the panel that feeds each machine. Inspect the circuit that is feeding the machine that is not "shocking" and then compare that feed to the machine that is. Be sure the ground to the panel and machine are tight and secure. Using an OHM meter simply check the continuity of the earth ground (be sure to power down before opening and checking panels) and do the same with the neutral to ground to be sure it is not picking up "noise" and releasing it at the machine.

Once you have inspected the feed do the same with the machine. OHM the groud to be sure the machine to feed is actualy good. Who knows it may all look good but it may be a break in the ground wire in the insulation.

Start with the basics and check off the list.