Caution: High voltage

You might have heard a lot of buzz about last year’s revision to OSHA’s electrical standard and how it incorporated the National Fire Protection Association’s NFPA 70E, Standard for Electrical Safety in the Workplace. That is not entirely the case.

OSHA revised its electrical standard, but it revised only one section, the Design Safety Standards for Electrical Systems (29 CFR 1910.302 through .308). It didn’t touch the Safety-Related Work Practices section (29 CFR 1910.331 through .335).

So, the bottom line is, nothing has changed regarding arc flash, working on deenergized electrical systems, working on live electrical components, lockout/tagout procedures or electrical personal protective equipment (PPE).

If you have been doing things correctly in the past, then this article will be a refresher. If you’re not sure you’re doing things right, this article might help you to get on track.

Lockout/tagout remains key

It really needs to be emphasized that when working on electrical systems, the required way to protect employees is electrical lockout/tagout (Figure 1). This requirement hasn’t changed. OSHA says in §1910.333(a)(1):

Live parts to which an employee may be exposed shall be deenergized before the employee works on or near them, unless the employer can demonstrate that deenergizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations. Live parts that operate at less than 50 volts to ground need not be deenergized if there will be no increased exposure to electrical burns or to explosion due to electric arcs.

Note 1: Examples of increased or additional hazards include interruption of life support equipment, deactivation of emergency alarm systems, shutdown of hazardous location ventilation equipment, or removal of illumination for an area.

Note 2: Examples of work that may be performed on or near energized circuit parts because of infeasibility due to equipment design or operational limitations include testing of electric circuits that can only be performed with the circuit energized and work on circuits that form an integral part of a continuous industrial process in a chemical plant that would otherwise need to be completely shut down in order to permit work on one circuit or piece of equipment.

Figure 1

OSHA hasn’t changed the requirement in 29 CFR §1910.333(a)(1) that says, “Live parts to which an employee might be exposed shall be deenergized before the employee works on or near them, unless the employer can demonstrate that deenergizing introduces additional or increased hazards or is infeasible because of equipment design or operational limitations.”

The NFPA 70E has a similar requirement, except that the term “electrically safe work condition” is used instead of “deenergized.” The 70E places this requirement, just as OSHA does, ahead of donning appropriate PPE and working on live electrical systems or components. Both documents provide specifics on how to achieve this deenergized state or electrically safe work condition using lockout/tagout procedures and devices.

Quite often, employers try to take advantage of the terms “operational limitations” and “continuous industrial process” to justify not locking out and tagging electrical systems before work is done. OSHA hasn’t addressed the terms and conditions for working on live electrical systems. However, a December 19, 2006 OSHA Letter of Interpretation, Continuous Industrial Processes and the Infeasibility of Deenergizing Equipment Under 29 CFR 1910.333, sheds some light on the issue. (You can read all the letters mentioned in this article on the OSHA Web site at www.osha.gov.)

Avoid working live

For electrical work, you don’t want your maintenance technicians to don PPE unless it’s absolutely necessary. Voltage-rated rubber gloves and leather protective gloves are unwieldy. It also can be difficult to work on electrical equipment with other PPE they might have to wear, such as face shields, flash suit hoods and jackets. The OSHA requirement at §1910.335(a)(1) says:

Employees working in areas where there are potential electrical hazards shall be provided with, and shall use, electrical protective equipment that is appropriate for the specific parts of the body to be protected and work to be performed.

This language doesn’t provide the specifics an employer needs to follow to protect technicians against electrical hazards.

OSHA also says in §1910.132(d) that employers must perform a hazard assessment and equipment selection, and document the hazard assessment. However, OSHA provides no help when determining what electrical PPE employees should wear. Fortunately, the NFPA 70E provides excellent help in determining specific hazards and appropriate PPE for electrical workers. (You can order the NFPA 70E on the National Fire Protection Association’s Web site.)