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Author Topic: Arc Flash Safety  (Read 2040 times)

Stephen Swaffer

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Re: Arc Flash Safety
« Reply #20 on: January 22, 2014, 11:22:27 pm »

from NEC 2014

....marked to
warn qualified persons of potential electric arc flash hazards...shall be located so as to be clearly visible to qualified
persons before....

Why do "qualified" people need to be warned that an arc flash hazard exists inside an electrical panel?  Shouldn't that be a crucial part of their "qualification"?
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Steve Swaffer

Mike Sokol

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Re: Arc Flash Safety
« Reply #21 on: January 23, 2014, 06:46:12 am »

Why do "qualified" people need to be warned that an arc flash hazard exists inside an electrical panel?  Shouldn't that be a crucial part of their "qualification"?

Well, yeah.... And these were big 3-phase panels that DIY guys have NO BUSINESS being inside of. But the NFPA has got to start somewhere, I suppose. I've met a lot of "old" electricians who don't know or follow code anyway, so perhaps a warning label on the box will make them think/ask about Arc-Flash before they dive into one.

Mike Sokol

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Mike Sokol

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Re: Arc Flash Safety
« Reply #23 on: January 28, 2014, 08:23:23 pm »

FYI: The January issue of EC&M has a very good article about Arc Flash Calculations vs. Tables. Read it at http://ecmweb.com/january-2014#46

I've not had time to read the entire article yet, but I'll absorb it over the next few days.

Mike Sokol

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Re: Arc Flash Safety
« Reply #24 on: February 20, 2014, 09:02:11 pm »

Just in Rochester NY this morning... A very bad Arc-Flash burn to a subcontractor. Here's a link to the newspaper story.

http://www.democratandchronicle.com/story/news/2014/02/20/hurt-rochester-explosion/5640609/

Text of the article is pasted below. 

A man was injured from an electrical explosion at Advanced Glass Industries Inc. on Emerson Street just before 11:30 a.m. Thursday.

Rural Metro Ambulance Services reported that the man, 57, was taken with flash burn to Strong Memorial Hospital after the explosion, which occurred at 1335 Emerson St. He received burns to 25 percent of his body, mainly to his face, hands and arms, according to Capt. Joseph Luna of the Rochester Fire Department.

The man was a subcontractor who had been hired by the business to do electrical maintenance work, said Rochester Fire Department Battalion Chief Dan Mancuso. He said an electrical arc, or an exposed current between two conductors, caused the injury.

Advanced Glass Industries is one of the world's largest suppliers of precision machined optical glass blanks, molded optical glass blanks and slumped optical glass blanks, according to the company's web site. The company was founded just after World War II as Fischer Optical, according to the website.

Mike Sokol

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Re: Arc Flash Safety
« Reply #25 on: March 03, 2014, 05:54:10 pm »

Iowa OSHA Issues Citations for Arc Explosion

Workers connecting an energized 800-amp panelboard without proper safety training or PPE creates some very dangerous arc-flash injuries.  See link and article text below.

http://tinyurl.com/kssnpww 

The Iowa Division of Labor Services Occupational Safety and Health Bureau has cited three entities in an arc flash explosion last July in Sibley, Iowa. I-OSHA says the accident happened when workers were switching over electric lines at Timewell Drainage. After its investigation, I-OSHA cited City of Sibley Electric Department, Timewell, and Current Electric of Sibley.

KIWA Radio reported that the issue occurred when workers were installing new electrical wiring to an 800A interior panelboard. I-OSHA said work was being performed while the wiring was energized, and people were allowed in the immediate area without personal protective equipment (PPE). After installation of wiring to the panelboard, the employer was confirming that proper function of the equipment had been achieved. Lock and tagout was not applied, ensuring that the equipment was not energized prior to installation of the panel cover. The reportt stated that people were in the immediate area and were exposed to an arc flash and/or arc blast, and life-threatening injuries were sustained.

Five people were sent to the hospital.

According to I-OSHA and the radio report, Current Electric should have conducted frequent and regular inspections of job sites, materials, and equipment. Current Electric supposedly did not instruct each employee in the recognition and avoidance of unsafe conditions and the applicable regulations.

Last fall, Timewell Drainage was cited for not instructing their employees in the recognition and avoidance of unsafe conditions, and for employees not wearing PPE. The City of Sibley Electric Department was cited because controls deactivated during the course of work on energized or de-energized equipment or circuits were not tagged on the worksite involving the energizing and deenergizing of a transformer with an incoming line voltage of thousands of volts.

Stephen Swaffer

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Re: Arc Flash Safety
« Reply #26 on: March 04, 2014, 10:38:49 am »

This article mentions another issue with arc flash and that is safety area/barrier.  The standard specifies a distance for wearing PPE, another that "qualified" personnel are allowed to approach and a greater distance for non-qualified people.  Bottom line=expose as few people as necessary to the arc flash hazard.  I usually ty to form some sort of barricade-doesn't take much -to keep people back. One, to keep them from a hazad, two, the last thing I want if I am n an energized panel is a non electrician trying to look over my shoulder-especially if I need to get away!

Interestingly, I was redoing a similar service a year ago and redoing underground service conductors to a transformer.  The POCO employees asked me if the I wanted primaries (less than 3 feet from where I was digging) de-energized.  Really? You have to ask?
w
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Mike Sokol

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Re: Arc Flash Safety
« Reply #27 on: March 04, 2014, 11:44:17 am »

This article mentions another issue with arc flash and that is safety area/barrier.

Also, failure to use Lock and Tag-Outs is a VERY dangerous thing. That's the first thing I learned to do back in the 70's when I was working on industrial power. 

Lyle Williams

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Re: Arc Flash Safety
« Reply #28 on: March 04, 2014, 02:05:38 pm »

This article mentions another issue with arc flash and that is safety area/barrier.  The standard specifies a distance for wearing PPE, another that "qualified" personnel are allowed to approach and a greater distance for non-qualified people.  Bottom line=expose as few people as necessary to the arc flash hazard.  I usually ty to form some sort of barricade-doesn't take much -to keep people back. One, to keep them from a hazad, two, the last thing I want if I am n an energized panel is a non electrician trying to look over my shoulder-especially if I need to get away!

Interestingly, I was redoing a similar service a year ago and redoing underground service conductors to a transformer.  The POCO employees asked me if the I wanted primaries (less than 3 feet from where I was digging) de-energized.  Really? You have to ask?
w

Of course underground infrastructure is always exactly where the city records say it is....   :-)

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Corey Scogin

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Re: Arc Flash Safety
« Reply #29 on: March 04, 2014, 02:24:55 pm »

Also, failure to use Lock and Tag-Outs is a VERY dangerous thing. That's the first thing I learned to do back in the 70's when I was working on industrial power.

At my industrial manufacturing day job there's one more item added to that list: Lock Out, Tag Out, Try Out.  Verification is also important.
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