"I wasn’t wearing my safety gear."
In the field of Electrical Engineering, one often hears about Arc Flash incidents and shudders as they recall risks taken and mistakes made in their own careers that could’ve led to such a catastrophe. The real, gruesome truth about Arc Flash incidents is that many do not live to tell the tale, and of those who do, most are unable to lead a normal life after. The following article tells the story of two men who survived Arc Flashes. In the aftermath, one leads a normal life thanks to his Personal Protective Equipment and one is still paying the price for his disregard of safety standards. Both are fortunate to be alive and their stories provide a valuable lesson to all: no matter what trade you work in, safety must always be the highest priority.
This is a great article from IAEI Magazine that explains the aftermath of an Arc Flash incident and what you can do to keep yourself safe. (Article written by: Thomas A. Domitrovich)
IEEE 1584 Working Group Moves Forward with New Modeling and Standard Revisions
On Sunday 1/30/12, members of the IEEE 1584 Working Group met in Daytona Beach, FL to discuss the latest IEEE/NFPA Collaboration Testing report and to discuss changes to the IEEE 1584 Standard. The meeting was attended by approximately 48 engineers and technicians from across the United States and Canada.
The IEEE/NFPA Collaboration Study is an attempt to improve the energy and arc flash boundary equations currently shown in the guide. A significant increase in the number of tests is being undertaken to study the effects of (1) Heat and Thermal effects, (2) Blast Pressure, (3) Sound, and (4) Light hazards. These tests are being done at 600, 2,400, 4,160, and 13,800 Volt equipment. Some tests at 208 Volts have been done in an attempt to determine the minimum size that will sustain an arc flash on the secondary terminals. (See the discussion in previous blog entries and below)
One of the more interesting phenomenons is the extremely high light level that occurs for an arc flash. Tests have shown that some of the arc flash tests had light levels of 120 times that of looking at the sun. This high level surprised the testing group. Future NFPA 70E revisions will most likely add arc flash eye protection similar to welding flash eye protection.
The testing group plans to deliver a draft model (equations) by April 2012 to the IEEE 1584 working group members. It will be our job to try out the model and see how they compare to the past 1584 equations and Lee equations.
After April, the testing group will proceed with DC arc flash testing with the goal of developing a model for DC arc flash energies and boundaries.
The current standard published the equations and provided the user with an Excel Spreadsheet with the equations imbedded. It allowed the user to calculate the energy levels and arc flash boundaries. The IEEE/NFPA Collaboration group feels that equations in the current standard have been copied, used in other computer programs and at times, misapplied.
The new standard will use a “Black Box” method of calculation. The new standard will include an executable program that will allow the user to input the appropriate data and the arc flash energy and boundary will be displayed. Neither equations nor spreadsheet to show what the equations are will be provided. Software companies such as SKM, ETAP, EasyPower, and others will license the “Black Box” function from IEEE. The software companies will imbed this black box program into their software.
The IEEE 1584 Committee has a very ambitious schedule. The current schedule will have the Standard revised, approved, and voted on by the end of 2012.
While the testing group continues their efforts, the 1584 committee members continued to revise the current text.
One of the most controversial items in the current Standard 1584® IEEE Guide for Performing Arc-Flash Hazard Calculations is the exemption for systems less than 240 volts and fed by transformers rated 125 kVA or less. Section 4.2 page 6 states, “Equipment below 240 V need not be considered unless it involves at least one 125 kVA or larger low impedance transformer in its immediate power supply.”
There are two problems with this statement. The first is that IEEE 1584 Standard is for three phase systems only and it is not to be used for single phase systems. A 125 kVA transformer is a standard single phase transformer size and not a standard three phase transformer (the closest standard three phase size is 112.5 kVA)
The second problem is the assumption that there is no serious arc flash hazard for these systems. Testing last spring by the IEEE/NFPA Collaboration group found that some 208 Volt transformer secondaries can sustain an arc flash. Most of the IEEE 1584 working group members feel that 125 kVA is too high but the group could not come to a consensus as to what the lower transformer size should be.
A motion was made and approved to form a subcommittee to continue the discussion and investigation of this very important cut off transformer size.
State of WA L&I approves e-Hazard’s 2012 NFPA-70E Refresher Course for (4) Electrician CEUs
The State of Washington Department of Labor & Industries has approved e-Hazard.com’s Low Voltage Qualified Electrical Safety Refresher course. This seminar is based upon the new 2012 NFPA-70E – Electrical Safety in the Workplace. Four CEU credits will be given to electricians who are registered with the State of Washington. This is a great way to get CEUs and learn about the latest NFPA 70E changes.
Low Voltage Qualified Refresher
4 Hours – 4 CEUs
This class keeps attendees current on the information gained in the standard Low Voltage Qualified class. In addition to a review of standard electrical safety principles, attendees also receive an update on NFPA 70E guidelines and requirements from the 2009 version to the recently instated 2012 version.
Dates & Costs
Please call Robert E. Fuhr at 253-639-8535 Ext 101 or send requests to email@example.com
What You’ll Learn
· Electrical Safety Facts
· Regulations & Standards
· Electrical Hazards & Protection Strategies
· Personal Protective Equipment
· Hazard Assessment
· Safety Related Work Practices
Who Should Attend
· Electrical engineers
· Electrical technicians
· Electrical foremen
· Electrician apprentices
· Electrical programmers & troubleshooters
· Anyone working with up to 600 volts
· Anyone who may exposed to energized, uninsulated or live circuit parts & conductors
More Cities Adopt the Washington Cities Electrical Code
Are your Electrical Specifications Ready for the Washington Cities Electrical Code?
The Washington Cities Listed below have or will soon be adopting a new set of Electrical Codes. The Washington Cities Electrical Code will be used to supplement the National Electrical Code (NEC). The date that each city will be adopting the code will vary. The following are the cities that have adopted the new code.
Cities who are involved and may be adopting this Code are:
Section 110.16 of the new Washington Cities Electrical Code (WACEC) states that arc flash labels shall be attached to electrical equipment. The labels must contain the Hazard Risk Category (HRC) and the Arc Flash energy level (cals/cm2). This requirement goes above and beyond the Section 110.16 of the NEC. The NEC allows generic Arc Flash labels warning only that there is a hazard. The Washington Cities Electrical Code (WACEC) will not allow generic Arc Flash labels.
Arc Flash energies are based upon the available fault current at each piece of equipment and the time that it takes for the upstream device to operate (trip or blow).
SAMPLE ARC FLASH LABEL
An arc flash study can be performed only after:
- Utility information is known
- Transformer Size and Impedance
- Primary Protection (Mfg, Type, & Size)
- Minimum and Maximum available Primary Fault Current
- Protective device data (Mfg, Type, & Size) to be installed or is already installed has been collected.
- Protective Device Coordination Study (breaker and relay settings) has been completed.
Proper specifications are extremely important to the success of any project. Detailed Power System Study (Short Circuit, Protective Device Coordination, & Arc Flash) specifications will help to ensure the studies are performed accurately. These studies must be preformed before the equipment is to be energized.
To assist you with this new requirement, we have created Power System Study Specifications. These will help you and your company avoid many of the common pitfalls when specifying these important studies. Please feel free to use these specifications for your projects.