Lock It Out: Follow lockout/tagout procedures to establish an electrically safe work condition

By Michael Johnston | May 15, 2021
Shutterstock / Dennis Cox






May is Electrical Safety Month. As one of OSHA’s “Focus Four,” it is vital that appropriate attention is placed on attaining and maintaining electrical safety in the workplace, not just in May, but year-round.

The National Electrical Code is primarily a prescriptive installation code, while NFPA 70E, the Standard for Electrical Safety in the Workplace, is all about electrical safety for workers. These two regulatory documents work hand in hand when it comes to the general requirement to shut electricity off before working on equipment or conductors.

As outlined in Section 110.1 of NFPA 70E, it requires that elimination, as it appears in the hierarchy of risk controls, is the first priority. This means that one should strive for establishing an electrically safe work condition, unless energized work is justified in accordance with OSHA regulations and NFPA 70E.

This article takes a look at how some of the NEC’s very specific installation requirements correlate directly with the primary objectives of NFPA 70E. It addresses three electrical hazards—electric shock, arc flash and arc blast.

Whether it is temporary power or part of a facility’s permanent electrical system, electrical hazards are present. How those hazards are managed is directly related to effective safety management systems and company policies in effect at that facility.

An important component of any safety program is the required lockout/tagout program. The specific procedures of this required program are mandated by OSHA 1910.333(b) and NFPA 70E. More specifically, 29 CFR 1910.333(b)(2)(ii)(A) requires that, before deenergizing circuits and equipment, safe procedures for doing so must be determined.

NFPA 70E Section 120.5(1) requires determining all possible sources of electrical supply to the specific equipment. Check applicable up-to-date drawings, diagrams and identification tags. 29 CFR 1910.333(b)(2)(ii)(B) indicates that circuits and equipment to be worked on shall be disconnected from all electrical energy sources. Control circuit devices such as push buttons, selector switches and interlocks may not be used as the sole means for deenergizing circuits or equipment. Interlocks for electrical equipment may not be used as a substitute for lockout and tagging procedures.

Now, let’s review how the NEC correlates with NFPA 70E to help facilitate establishing an electrically safe work condition through use of lockout/tagout. The NEC contains many requirements for equipment disconnecting means to be installed “within sight from” the equipment it supplies. The phrase “in sight from, within sight from or within sight,” basically means that the disconnect must be visible from and not more than 50 feet from the equipment.

There are many exceptions that permit this required disconnect to be located out of sight of the equipment it supplies. This is when the specific language in NEC Section 110.25 applies and clearly indicates prescriptive requirements relative to being able to lock a remote disconnecting means in the open (off) position.

The rule clarifies that if a disconnecting means is required to be lockable in the open position, as in many exceptions to the general “in sight from” disconnect rules, the provisions for locking the disconnecting means must be installed as a part of the permanent installation. The locking provisions remain with the switch or circuit breaker, whether or not the lock is installed. It is there so personnel can establish an electrically safe working condition with the open or off position and comply with OSHA regulations and NFPA 70E.

One distinct difference between NFPA 70E and the NEC in this regard is that 70E will recognize portable locking means that can be carried to the equipment to perform a lockout procedure. The NEC requires the provisions to be part of the installation so that personnel can just install their lock when implementing lockout/tagout procedures.

The correlation between the NEC , OSHA regulations and NFPA 70E in this case is just one of many rules that are continuously being updated and improved to address the reduction of electrical injuries and fatalities related to nonconformity of lockout/tagout rules. Another important reminder is that along with lockout/tagout operations comes complete establishment of an electrically safe work condition. This includes verifying that voltage test instruments are operational, checking for the absence of voltage on the equipment to be worked on and then reverifying the operation of the test instrument once again. Part of a lockout/tagout operation could also include use of temporary personal protective grounding equipment, where determined to be necessary.

As always, it is important to ensure employees receive all required training, including the use of test instruments in addition to lockout/tagout. If employees are unfamiliar with the installation requirements of the NEC and the workplace electrical safety requirements, get them trained.

About The Author

A man, Mike Johnston, in front of a gray background.

Michael Johnston

NECA Executive Director of Codes and Standards

JOHNSTON is NECA’s executive director of codes and standards. He is a member of the NEC Correlating Committee, NFPA Standards Council, IBEW, UL Electrical Council and NFPA’s Electrical Section. Reach him at



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