Arc Flash & Electrical Safety: May 2007

Wednesday, May 30, 2007

Mine Blast Kills 39 Workers

This news item caught my eye because I've just returned from a 12 day trip to Russia. Last Thursday an explosion in a Russian coal mine resulted in the death of 39 workers. This is the second major coal mining disaster in Russian in the past two months. In March a coal mine explosion resulted in the deaths of 110 workers.

What was the cause of this most recent tragedy? The Moscow Times reports:

"Alexander Sekachyov, spokesman for the agency's Southern Federal District office, said a preliminary investigation of the affected coal faces in the Yubileinaya mine revealed that a power cable had become detached from a coal-cutting machine, electrifying its exterior. This resulted in an electric arc or a spark that produced the initial blast, which then ignited coal dust in the mine, he said."

Labels: Electrical Safety, Mining

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Tuesday, May 29, 2007

Medical Treatment - Electrical and Arc Flash Burns

Detailed medical information about electrical and arc flash burns, including descriptions and treatment information, is available on the eMedicine web site.

Authored by Elizabeth A Liotta, MD and Dana Borgeson, DO, this article provides medical information for doctors and others who are involved in the treatment of electrical burns. This is not a first aid article, but a detailed medical treatment article. It covers everything from a description of electrical injuries to medical and surgical care.

The following is an example from the Medical Care section:

"Life-saving measures should be continued at a medical center at which patients with multiple trauma can be treated most appropriately. Optimally, the center should have an adequate burn unit or the ability to treat patients with burns. Secondary assessments are performed here as well.

* With at least 2 large-bore intravenous lines and a Foley catheter in place, parenteral fluid therapy should be administered to maintain a urine output of at least 0.5-1.0 mL/kg/h. However, if heme is present in the urine, urine output of 1.0-1.5 mL/kg/h should be maintained.

o The rule of nines for fluid resuscitation generally causes underestimation of the fluid requirements in patients with electrical burns (as opposed to those with only typical thermal burns). The reason is because of the higher likelihood of a significant or deep injury with electrical burns (Kennedy, 1998).

o Two caveats to this fluid-management regimen bear consideration: (1) In patients with head injuries, parenteral fluids may need to be relatively restricted, or adjunctive therapy may be required to prevent cerebral edema. (2) In preadolescents, fluid requirements may need to be adjusted on the basis of their body surface area or an age-specific diagram (Sheridan, 2001)."

Labels: Electrical Injuries

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Wednesday, May 16, 2007

Arc Flash Myths and Misconceptions

Daryl Lewellyn of Lewellyn Technology has written a good article about the wrong "knowledge" and misunderstandings people have about arc flash. Many of these come from trying to apply past experience to arc flash, and that is not always the best thing to do.

The article is available in PDF form at: http://www.lewellyn.com/pdf/os_pdf/Arc%20Flash%20Myths%20and%20Misconceptions.pdf

It covers five myths:

1. A current limiting fuse will always reduce the arc flash hazard

2. The arc flash hazard downstream will always be less than upstream

3. An arc flash analysis is about labeling panels

4. We don't have to do an arc flash analysis because we do regular infrared scans of our equipment

5. NFPA 70E is mostly about arc flash

Labels: Arc Flash Training, Preventing Arc Flash Accidents

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Tuesday, May 15, 2007

Follow Standards When Selecting Personal Protection For Arc Flash Hazards

Yesterday's issue of Plant Services Magazine includes an article decribing the process of selecting the proper PPE for arc flash protection. You can read the article at: http://www.plantservices.com/articles/2007/096.html

The article starts by describing the: "Four-step hazard calculations: First, establish the job’s hazard risk category. Second, determine what clothing and equipment the hazard risk category requires. Third, identify what arc thermal performance value (ATPV) rating is necessary. Finally, select personal protective equipment that meets or exceeds the designated ATPV rating."

It then goes on to provide a quick overview of some of the recent improvements in PPE protection and comfort provided by specific PPE manufacturer's products.

Labels: Arc Flash PPE

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Friday, May 11, 2007

Severe Burns Received From 11Kv Arc Flash Explosion

Ferret.com.au reported that an electrician in Australia was injured in an arc flash explosion in a mine switchroom. The article states:

"A CONTRACT electrician recommissioning high-voltage electrical equipment in a mine site switchroom has been severely burnt by an 11kV arc flash explosion inside the cubical containing the main incoming circuit breaker."

The electrician was apparently following the proper proceedures and the cause of the arc flash is not known.

You can read the complete article at: http://www.ferret.com.au/articles/8d/0c049b8d.asp

Labels: Arc Flash Accidents

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Tuesday, May 08, 2007

Two Injured In Arc Flash Accident at Alcoa

The Quad-Cities Online (Iowa) reports today that two contractor employees at the Alcoa Davenport Works were injured by an arc flash incident yesterday. The article reports:

"Alcoa spokesman John Riches said the two contractors were doing routine maintenance on a high-voltage electrical substation just outside the Riverdale plant. He said one person sustained severe electrical burns when he or she became grounded, creating an arc flash at about 1:30 p.m."

"A second contractor who was some distance away from the first also was burned but not as badly, according to Mr. Riches. The second contractor was transported by ambulance to a local hospital."

You can read the complete story at: http://qconline.com/archives/qco/display.php?id=337424

It is interesting to read the public comments that are attached to this article. They provide a different perspective showing a small part of how industrial safety is perceived by the public.

Labels: Arc Flash Accidents, Electrical Injuries

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Thursday, May 03, 2007

Rochester Public Utilities Worker Burned in Arc Flash Accident

The Rochester, Minnesota Post-Bulletin reported yesterday that a lineman for Rochester Public Utilities was burned by an arc flash. The newspaper reported that:

"The man, one of about 20 line workers for the utility, was injured at a transformer while extending power to a construction site in the 500 block of Third Avenue Southeast, just south of the downtown area, Benson said. The injured worker's name is not yet being released by RPU officials."

"Benson said the lineman suffered 'arc flash burns,' and was burned on his arms, stomach and face."

The lineman was wearing PPE including a flame retardant shirt, gloves, safety vest, glasses and a hard hat.

Read the complete article.

Labels: Arc Flash Accidents, Electrical Injuries

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Tuesday, May 01, 2007

Construction Industry - Protection from Electric Shock and Arc Flash

The Center to Protect Workers' Rights has written a paper that is available on the CDC eLCOSH website. The paper discusses arc flash hazards in the construction industry. The opening paragraph introduces the subject of the paper.

"About 50 electrical workers are killed in construction every year in the U.S. by electric current and many more are injured. Over half of the deaths are from working on energized ('live') electric circuits without proper protection - often when it was not necessary to work 'live.' At least one-third of the electrocutions occur at low voltage, under 600 volts. This paper discusses precautions for electricians, but does not cover electric utility work."

This paper provides detailed information for electricians and supervisors, covering topics such as: "To De-Energize or Not to De-Energize". In the introduction to this section the paper states:

"The most important principle of electric safety is, assume electric circuits are energized unless you make sure they are not. Test every circuit and conductor every time you work on them."

A major portion of this "De-Energize" section discusses lockout/tagout and how an effective and safe lockout/tagout systems should work.

In the "Not to De-Engergize" section the paper discusses the precautions and proceedures that should be used when working on live equipment. It defines approach boundaries and describes the use of PPE (personal protective equipment).

Detailed tables providing specific risk categories for various types of live work are provided at the end of the paper.

Labels: Electrical Injuries, Electrical Safety

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