Shock From a Copy Machine Imigistics C650

[thermalsensing]

I am involved in a situation where a woman got severely shocked from an Imigistics C650 high speed copy machine.
She was trying to clear a paper jam with a screw driver in an area where there is not suppose to be any power.
She was kneeling down near a vertically hinged door. Her eye glasses were burnt and melted and there is a burn on the inside of her right shoe.
When this happened the 110 volt grounded 3 wire cord was unplugged.
In the service manual for the machine the manufacturer calls for a separate ground wire from a ground point ( such as the ground at the outlet )to the frame of the machine. There was no separate ground wire to the machine. I feel that the separate ground wire would have prevented the accident.
Does any one know if their is ANY REQUIREMENTS TO HAVE THE SEPARATE GROUND WIRE?
Has anyone been involved in anything of a similar nature ?
Can the capacatiors in the machine discharge some how ?
I have found one other incident on the internet where someone was shocked but I do not have any details.
If some one has any theories please let me know.
Thank You
Bob Kopelman


Edit, removed personal info, please use a PM to exchange contact info.

 

[iwire]

Bob, I have to make clear this forum can not be used as a source of legal information.

What is your role in this incident?

 

[thermalsensing]

Copier

Copier

I was asked to try and figure how something like this can happen ?

I have run out of ideas. I was hoping someone would know something so that this can not happen in the future.

 

[jim dungar]

Playing the "what if" game and with no intention of actual forensic help, but was the machine fed by more than one power cord? I have seen some office machines where there is a separate feed for a collator.

 

[brian john]

I feel that the separate ground wire would have prevented the accident.

I would avoid making statements like this unless you have solid evidence of what caused the incident. I would limit my statements ONLY to the party paying me and limit opinions to statements that have solid back up.

Your profile says contractor, are you an electrical contractor?

If the manufactures requires a separate ground it should be installed.

Has the service rep been to look at the equipment?

Has the insurance investigator looked at the equipment?

Are there caps in the unit? If so after disconnecting power how long does it take for them to discharge, with and without a supplemental ground.

In my expierence, injured parties seldom either know what actually happened or tell the complete truth. HOW DO YOU KNOW THE POWER WAS ACTUALLY DISCONNECTED?

 

[infinity]

As Brian mentioned I would expect an unplugged machine to only give a shock if the person made contact with a charged capacitor. That is if this machine even has capacitors. Given the scant details about the incident it's rather hard to even guess as what happened.

 

[iwire]

I have run out of ideas. I was hoping someone would know something so that this can not happen in the future.

After spending a lot of years doing machine maintenance I would suspect someone is not telling the whole truth. IMO the power cord was in fact plugged in.

Is there anyway to know for certain that the cord was unplugged before the incident?

That said IMO this is an issue for the machine manufacturer not a contractor.

 

[iwire]

Are there caps in the unit?

Her eye glasses were burnt and melted and there is a burn on the inside of her right shoe.

I am not that knowledgeable about caps but that sounds like a it would take a heck of a set of caps to do that much damage.

 

[winnie]

Bob,

It would take more than a heck of a set of capacitors to cause current to flow from an _ungrounded_ machine though a person's body and then through their shoe. Not impossible, if the machine itself had a tremendous static charge relative to earth...

Shorting a capacitor bank with a screwdriver could cause a pretty significant arc explosion, and sticking a screwdriver into a charged electrolytic can give you the whole fireworks show, complete with flaming bits of aluminum.

-Jon

(Hey, that's cool. I just installed FireFox 2, and it is spell checking what I type in the edit window....)

 

[iwire]

It would take more than a heck of a set of capacitors to cause current to flow from an _ungrounded_ machine though a person's body and then through their shoe.

Good point.

(Hey, that's cool. I just installed FireFox 2, and it is spell checking what I type in the edit window....)

Thanks, lack of spell check kept me from using Firefox for the forums. :smile:

 

[thermalsensing]

Accessories for C650

Accessories for C650

There is a stapler and a collator . They have a low voltade cord coming from the copier with a separate cord. The manufacturers rep. is saying that there is nothing wrong with the machine.
There were three people that are saying the machine was un plugged ( 110 Volt ) before she tried to remove the paper jam.
I checked the floor outlet it was plugged into and found 330 miliamos between the neutral and the carpet that she and the machine were on.
I also got about 6 volts between the neutral and the ground of the outlet.
The outlet is a surface floor molding outlet that gets its power from floor duct.
There are 2 circuits coming from the floor duct, each with there own neutral and there own ground wire. ( It is all # 12 wire ) Outlets are 20 amp rated and I can not find any problems with the outlets. Is there any way for the Floor Duct to act as a choke by not being grounded at the panel and not being grounded at the floor duct exit with a separate mechanical connection to the floor duct

 

[winnie]

I checked the floor outlet it was plugged into and found 330 miliamos between the neutral and the carpet that she and the machine were on.
I also got about 6 volts between the neutral and the ground of the outlet.

The above measurements are so strange as to make me suspect measurement errors; either misunderstanding the limits of the meter being used, or misreading of the results.

Neutral should be very near to ground potential, and a carpeted floor should not be nearly conductive enough to carry 330mA. 330mA at less than 6V would mean some sort of intentional conductive material added to the flooring.

With modern high impedance digital volt meters, it is quite easy to measure several volts on what is really an _open_ circuit.

-Jon

 

[peter d]

With modern high impedance digital volt meters, it is quite easy to measure several volts on what is really an _open_ circuit.

-Jon

I was doing a voltage check on an 480 volt RTU we just wired. I checked the first two phases, and then the next phase I had something like 80 volts on the third phase to netural.

We had to use two different pieces of MC cable (10/4 MC) and the electrician who spliced it used black, red white and capped the blue, while I used black, red, blue at the unit and capped the white. It was connected black, red, blue at the breaker. Obviously it was an open on Line 3, but I was still reading voltage.

This, I assume, is due to capacitance from the other live conductors in the cable.

 

[Pierre C Belarge]

I was doing a voltage check on an 480 volt RTU we just wired. I checked the first two phases, and then the next phase I had something like 80 volts on the third phase to netural.

We had to use two different pieces of MC cable (10/4 MC) and the electrician who spliced it used black, red white and capped the blue, while I used black, red, blue at the unit and capped the white. It was connected black, red, blue at the breaker. Obviously it was an open on Line 3, but I was still reading voltage.

This, I assume, is due to capacitance from the other live conductors in the cable.

that is sometimes called "ghosting".
Use of a selonoid type tester will solve that issue.

 

[petersonra]

In the service manual for the machine the manufacturer calls for a separate ground wire from a ground point ( such as the ground at the outlet )to the frame of the machine. There was no separate ground wire to the machine. I feel that the separate ground wire would have prevented the accident.
Does any one know if their is ANY REQUIREMENTS TO HAVE THE SEPARATE GROUND WIRE?

There is if the manual says there is. But if the power is unplugged where would the power come from to do any damage to a human being while the machine was unplugged. I am guessing the reason for the extra ground requirement is to reduce the buildup of electrostatic electricity while the machine is unplugged. I see no way the separate ground wire would have prevented this incident, providing the incident occurred as stated. IMO, the fact that you think it would suggests you are not the right person to be investigating this incident.

Can the capacatiors in the machine discharge some how ? I have found one other incident on the internet where someone was shocked but I do not have any details.

I think you would need to recreate the situation, but I have seen some pretty spectacular capacitor arcing when the terminals are shorted out. One would think that the manufacturer would have put some resistors across the caps to discharge them when power is turned off. If you want to get to the truth of this incident, it would be best to turn it over to someone with experience in this type of equipment. The most likely place for this expertise is the manufacturer.

 

[brantmacga]

why would you be taking measurements at the receptacle to find a problem if it was supposedly unplugged? the problem would lie within the machine itself, which i would imagine have to be disassembled to find the reason as to why she was shocked. not to get into legal aspects, and just answer this question to yourself, but is there a possibility of a lawsuit? if i stuck my hand somewhere it shouldn't have been and got fried, i'd too want to make it sound like it wasn't my fault. i read a story in TED magazine a couple of months ago about a guy who was severely shocked by a soda can coming out of a vending machine. supposedly, several people witnessed the accident and an electrician had been called out the week before to check a tripping breaker feeding the machine. the victim sued, and the lawyers had some engineer/investigator disassemble the vending machine to find the problem; they never found it.

 

[charlie b]

In the service manual for the machine the manufacturer calls for a separate ground wire from a ground point ( such as the ground at the outlet )to the frame of the machine. There was no separate ground wire to the machine. I feel that the separate ground wire would have prevented the accident.

I think you are misinterpreting the service manual?s statement. A connection between the frame of the machine and the ?ground at the outlet? is achieved by the ?third wire,? or ?ground wire,? that is part of the machine?s power cord. That, indeed, is the one and only purpose of that third wire.

The NEC has a requirement that all conductors be part of the same multi-wire cable, or to be routed within the same raceway (e.g., conduit or cable tray). There are a couple minor exceptions, but the power cord to a machine is not among them. That being the case, if you have a three-wire power cord (provided by the manufacturer), then the manufacturer is not permitted to tell you to install an additional wire from the frame to a ground point.

My guess is that the statement you refer to in the service manual is essentially telling you to use the three-wire cord and to plug it into a grounded receptacle outlet.

 

[petersonra]

I think you are misinterpreting the service manual’s statement. A connection between the frame of the machine and the “ground at the outlet” is achieved by the “third wire,” or “ground wire,” that is part of the machine’s power cord. That, indeed, is the one and only purpose of that third wire.

The NEC has a requirement that all conductors be part of the same multi-wire cable, or to be routed within the same raceway (e.g., conduit or cable tray). There are a couple minor exceptions, but the power cord to a machine is not among them. That being the case, if you have a three-wire power cord (provided by the manufacturer), then the manufacturer is not permitted to tell you to install an additional wire from the frame to a ground point.

My guess is that the statement you refer to in the service manual is essentially telling you to use the three-wire cord and to plug it into a grounded receptacle outlet.

I am not so sure. I don't believe that the copy machine or its cord is covered by the NEC, as it is not part of the premises wiring. Even if it was covered by the NEC, I don't see anywhere in the code that says you can't have an EGC that is seperate from the power conductors, only that there has to be an EGC with the power conductors.

 

[charlie b]

I agree that the copier?s power cord and plug are not covered by the NEC. But the connection of a bare copper wire (or one with green insulation) to a ?ground point? (i.e., to an EGC inside a receptacle outlet box) is covered. And it is forbidden by 300.3(B). Please note that 300.3(B) explicitly mentions "all equipment grounding conductors." To me, that means we can't run an extra EGC outside the machine's power cord.

What I think the OP has read into the service manual?s instructions is that the manufacturer wants the installer to get a bare copper wire, attach it to the frame, and then connect the other end to a ?ground point,? as described above. I strongly suspect that the manufacturer has made no such statement in the service manual, and that the OP has misunderstood what the service manual does say.

 

[petersonra]

I agree that the copier’s power cord and plug are not covered by the NEC. But the connection of a bare copper wire (or one with green insulation) to a “ground point” (i.e., to an EGC inside a receptacle outlet box) is covered. And it is forbidden by 300.3(B). Please note that 300.3(B) explicitly mentions "all equipment grounding conductors." To me, that means we can't run an extra EGC outside the machine's power cord.

What I think the OP has read into the service manual’s instructions is that the manufacturer wants the installer to get a bare copper wire, attach it to the frame, and then connect the other end to a “ground point,” as described above. I strongly suspect that the manufacturer has made no such statement in the service manual, and that the OP has misunderstood what the service manual does say.

To me 300.3 is meaningless since the power cord itself is outside the scope of the NEC.

How do you reconcile your reading of 300.3(B) with the fact that many times it is required that things be bonded together where there is no circuit? Such as for electrostatic electricity protection? I agree that all EGCs associated with a specific circuit need to be run with that circuit, but is there an NEC provision prohibiting you from adding additional bonding wires that are not associated with a specifc circuit? I would argue not, since the title of the paragraph you cite refers to conductors of the same circuit.

<added>If it matters any, I think Mr. Beck is probably right that the OP is misreading the service manual.