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Electrical shock 277 v

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Sahib

Senior Member
Location
India
I'm retired so I don't have access to company information that I would be permitted to share but here is a link relating to risk assessment in UK.
http://www.hse.gov.uk/risk/controlling-risks.htm

It is safety plan of the company. In OP's case it did not either exist or was not followed. What my suggestion is OP have a safety checklist of her own, one advantage of which is it keeps her alert about the hazards involved in her work such as the unexpected 277V shock she experienced.
 

kwired

Electron manager
Location
NE Nebraska
Occupation
EC
Yes. I missed out one thing. Test to ensure that the circuit really is dead.
All this should have been explained to her before the job was authorised.
Debatable whether an apprentice should have been allowed to undertake it anyway without senior supervision.
Simple voltage testing won't necessarily tell you a neutral is carrying current from some other circuit, until you open that neutral. That is why I said you can have a pretty good safety plan yet bad things can still happen. Someone getting shocked doesn't automatically mean anyone was totally negligent, can just mean something not considered has happened.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
It is safety plan of the company. In OP's case it did not either exist or was not followed. What my suggestion is OP have a safety checklist of her own, one advantage of which is it keeps her alert about the hazards involved in her work such as the unexpected 277V shock she experienced.
The risk assessment and method statement would be completed by the applicant and signed by her supervisor. They are for the specific project/task. We had them in duplicate pads so both we and our customer could keep a copy. But handwritten as a rule. but I'll see what I can find. But no promises.
 

drcampbell

Senior Member
Location
The Motor City, Michigan USA
Occupation
Registered Professional Engineer
Automotive main electrical systems are usually 12VDC. ...
Yes, that's why I said "24 volts" twice, to let everyone know it wasn't a typo or misunderstanding.

... 120 volt work light being involved would have raised my suspicion enough to warrant looking into it further.
I would have liked to have seen it investigated, too -- if it was a 24-volt fatality, it would have been one for the books.
But everybody did their job, and their job didn't include investigating.
The firefighters rendered the scene safe for the paramedics, and their job was done. There was no fire; they didn't suspect arson, and they didn't investigate.
The paramedics declared the guy was "not a viable candidate for resuscitation", (they're not legally empowered to say "dead") but paramedics don't investigate.
The cops didn't suspect a crime and didn't investigate.
The hospital declared the guy DOA and turned it over to the coroner.
The coroner ruled this death "accidental", didn't suspect foul play, and didn't investigate.

Apparently, there needed to be the likelihood of a felony and the possibility of sending someone to prison before an investigation could be initiated. Mere public safety and deeper scientific/medical understanding of electrical trauma doesn't meet the threshold.
 

kwired

Electron manager
Location
NE Nebraska
Occupation
EC
Yes, that's why I said "24 volts" twice, to let everyone know it wasn't a typo or misunderstanding.


I would have liked to have seen it investigated, too -- if it was a 24-volt fatality, it would have been one for the books.
But everybody did their job, and their job didn't include investigating.
The firefighters rendered the scene safe for the paramedics, and their job was done. There was no fire; they didn't suspect arson, and they didn't investigate.
The paramedics declared the guy was "not a viable candidate for resuscitation", (they're not legally empowered to say "dead") but paramedics don't investigate.
The cops didn't suspect a crime and didn't investigate.
The hospital declared the guy DOA and turned it over to the coroner.
The coroner ruled this death "accidental", didn't suspect foul play, and didn't investigate.

Apparently, there needed to be the likelihood of a felony and the possibility of sending someone to prison before an investigation could be initiated. Mere public safety and deeper scientific/medical understanding of electrical trauma doesn't meet the threshold.
I would think after hearing of a death presumably caused by electrocution that the state electrical authority wouldn't want to do their own investigation, just to establish what caused the electrocution even it is was truly accidental.

Life insurance, medical insurance, even workers compensation (if any applies) or anyone that may be interested in possible civil lawsuits may want some more information as well.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
It is safety plan of the company. In OP's case it did not either exist or was not followed. What my suggestion is OP have a safety checklist of her own, one advantage of which is it keeps her alert about the hazards involved in her work such as the unexpected 277V shock she experienced.

OK. This the brief introduction to a method statement we did or, more accurately, were required to submit prior to the commencement of the installation. Perhaps it will give you an idea of how seriously we took it.

An engineer will be in attendance at all times during the full term of the works. In the absence of the nominated supervisor a deputy will be appointed to assume this responsibility.
The supervisors’ main responsibilities will include: -

  • Ensuring safe methods of working are maintained during the contract.


  • To prevent/stop any person acting in an unsafe manner.


  • Ensuring adequate supply of personal protective equipment (PPE) is available and is maintained in good condition at all times.


  • Ensuring all relevant information including safety procedures (Toolbox Talks etc.), necessary or which have been supplied by (***) are brought to the attention of all employees and visitors.


  • Ensure all employees attend the (***) induction course prior to entering the site.


  • All works will be carried out in a safe and co-ordinated manner, in a way that it doesn’t pose a hazard to other operatives on the site.


  • Ensure all permits are signed off and copies left in the site file.


  • Make sure all power is off and isolated before commencing work.

There is also the risk assessment that goes with this but I'll spare you that for now.....​
 

Sahib

Senior Member
Location
India
Simple voltage testing won't necessarily tell you a neutral is carrying current from some other circuit, until you open that neutral. That is why I said you can have a pretty good safety plan yet bad things can still happen. Someone getting shocked doesn't automatically mean anyone was totally negligent, can just mean something not considered has happened.
This is where the usefulness of checklist approach lies:you consider various possibilities of hazard that could happen and compile them as one checklist for verification.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
This is where the usefulness of checklist approach lies:you consider various possibilities of hazard that could happen and compile them as one checklist for verification.
Yes. A risk assessment.
 

Sahib

Senior Member
Location
India
Yes. A risk assessment.
A risk assessment is more detailed: It includes assigning probability to each hazard event which may be beyond the capability of the OP. But a checklist is much easier to do: just a systematic checking of the conditions of work site for safety.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
A risk assessment is more detailed: It includes assigning probability to each hazard event which may be beyond the capability of the OP. But a checklist is much easier to do: just a systematic checking of the conditions of work site for safety.
It is for the specific task, not the generality of the work site as a whole.
And, as I mentioned before, we wouldn't have been allowed past the gates without a valid safety passport. One company had a demo room at security where you had to sit through a 30 minute safety video before even going on site.

The OP didn't want to complain probably for fear of losing her job. That I can understand in a way. But her foreman turned the power back on resulting in her electrocution. With correct safety procedures in place, he would not have been able to do that. But he did. It's just wrong at so many levels.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
...
... But her foreman turned the power back on resulting in her electrocution. With correct safety procedures in place, he would not have been able to do that. But he did. It's just wrong at so many levels.
Reread the OP. What you state above was my first impression, and would have made checking for voltage before starting insufficient. But on rereading, I think that what happened was that the foreman stated that he was going to turn the power off, but decided not to and the OP started work on an energized circuit.
Possibly the OP can clarify that point?
 

Sahib

Senior Member
Location
India
It is for the specific task, not the generality of the work site as a whole.
And, as I mentioned before, we wouldn't have been allowed past the gates without a valid safety passport. One company had a demo room at security where you had to sit through a 30 minute safety video before even going on site.

The OP didn't want to complain probably for fear of losing her job. That I can understand in a way. But her foreman turned the power back on resulting in her electrocution. With correct safety procedures in place, he would not have been able to do that. But he did. It's just wrong at so many levels.
All these: risk assessment, safety passport, demo room for a safety video, safety checklist etc have one common purpose. It is this: to have presence of mind which is liable to be lost under work pressure and subsequently could lead to casualties.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
For Sahib
Typical RA - apologies for the formatting. Pulled from a *.docx

ASSESSMENT FOR:- REF No:- NEXT REVIEW DATE:-
[h=1][/h][h=1]Electrical Insulation Testing 11 June 2010[/h]



CARRIED OUT BY:- DATE:-

**** June 2009



[h=2]Does this assessment consider the Health & Safety of pregnant workers? Yes[/h]Is a written working procedure involved? Yes



[h=3]POTENTIAL HAZARD(S):-[/h]
1. Electrical hazards.




[h=3]POSSIBLE RISK TO HEALTH & SAFETY:-[/h]

  1. Electric shock.




[h=4]PERSONS AT RISK:-[/h]
All users of the equipment.




EXISTING PREVENTION / CONTROL MEASURES:- ACTION WHEN:-

1. Visual examination Prior to use
2. Portable appliance maintenance variable but at least annually
3. Use lowest available voltage equipment As necessary
4. Only qualified persons are permitted to repair/test/maintain Always
electrical equipment.





SITE SPECIFIC HAZARDS:- ADDITIONAL CONTROL MEASURES:-

Site Name:
********
All portable electrical test appliances used on site is to be low voltage/cordless and have current valid test and calibration certification.







OVERALL RISK FACTOR:- LOW / MEDIUM / HIGH

Manager's signature:- Date:-

[h=5]Print name:- Joe Bloggs[/h]
 

Skokian

Member
Location
Skokie, Illinois
277 Vac Electric Shock.

277 Vac Electric Shock.

Firstly, I'm glad that she survived the contact with the 277 Vac source.

The worst electric shock I ever got was from 277 Vac.

I've done 480 Vac hand to hand but wasn't shocked much, mainly because at my age, the skin on the fingers is fairly dry.

I work on electric fire pump controllers which range from 30 to 300 Hp. 480 Vac is very typically the power source and is often service entrance.

I was working on an older controller tacking voltage readings while kneeling on a dry concrete floor and wearing levies. The back of my hand accidentally contacted the screw terminal of a limit switch which had line voltage 277/480 Vac Wye. I could feel the jolt thru my hand and knee. Fortunately the current burned a perfect 1/2" disc on the back of my hand which reduced the current enough for me to let go.

This was before I started using kneeling pads, which I believe would have greatly helped.
 
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