Factory Safety

In addition to the main types of certification, Factory Safety is addressed in the following topics:

Arc Flash

Arc Flash Label

What is an arc flash?

Arc Flash is a very fast explosive discharge of energy caused by a short circuit, similar to a magnesium flash bulb in an old style camera. Before the circuit breaker has a chance to trip (and clear the fault), a current of several thousand amps can flow for a few milliseconds. The metal conductor is converted to high temperature plasma which can cause permanent burns, shrapnel, shock wave trauma, blindness, and even death.

Introduction to arc flash:

Arc flash is the explosive delivery of hot plasma energy, with the effect being burns and bludgeoning. The energy is the product of the available power (voltage x current) and the time that it takes to clear the fault (open the circuit breaker or fuse). At the main panel of your home, the available energy (240 VAC x 7000 amps x 0.1 seconds) is equivalent to a stick of dynamite. But at an outlet, the available energy (120 VAC x 200 amps x 0.1 seconds) is more like a loud pop. For outlets, the energy is limited due to the fact that 12 gauge wiring has a resistance of about one ohm per 500 feet.

Arc flash is mitigated by reducing the current (adding resistance) and with faster clearing time. In addition, 1) avoid hot work, if possible, 2) wear appropriate PPE, 3) hazard warning labels, and 4) company policy and training. Lack of LOTO (lock-out tag-out) is the #1 Cal/OSHA citation for industrial factories.

In the US, there are ~8000 arc flash events per year and ~18 serious injuries per year. Over half of all electrical injuries involve burns. Historically, OSHA (and NFPA 70E) has been more concerned with electrical shock than with arc flash. The new NFPA 70E (2012) will emphasize arc flash, and will likely be adopted into 29CFR1910. Worker’s Comp insurance carriers (such as Chubb) are pushing for this.

Arc flash will require site-wide analysis of available energy at every panel, and energized work permits for activity > 50 volts, excepting only diagnostic and testing. (source: www.BAESG.org monthly meeting, July 20, 2011, arc flash presentation).

This video demonstrates the type of fatal accident that an arc flash can create

QEW Training

QEW Training: in the classroom or outside

Cal OSHA has extensive rules on accident prevention, electrical safety, machine guarding, and hazardous materials. A trained expert can tour the workplace and point out opportunities for improvement.

Training classes for QEW

Abstraction Engineering can conduct an informal two-hour training class for a small group of your Qualified Electrical Workers (QEWs) using my standard powerpoint presentation. The QEW training will include electrical hazards, qualifications, risk assessment, PPE, and dramatic YouTube vignettes. Abstraction Engineering will specify the presentation materials, text books, PPE examples, etc.

Typical Scope of Work

Abstraction Engineering would conduct an informal training class consisting of a 2.5 hour presentation (~60 slides) on electrical safety, PPE, and machine construction. Based on prior feedback, this class now includes a lot of “show and tell” and some dramatic “boom” videos from YouTube. The class can be customized to individual company policy and for LOTO practice on real machines.
The client would provide the room, projector, and screen. Recommended text books can be provided as necessary.

Suggested references

  • 100 Questions and Answers on Electrical Safety by Ray Jones, 2009, ~$15
  • A User’s Guide to Electrical PPE by Ray Jones, 2008, ~$15
  • Electrical Safety Code Manual by Kimberley Keller, 2010, ~$60
  • NFPA 70E Handbook for Electrical Safety in the Workplace, 2012, ~$135
  • Electrical Safety Handbook by John Cadick, et al, 4th edition (April 2012) ~ $65
  • An Illustrated Guide to Electrical Safety by ASSE, 6th edition ~ $80


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