OSHA Replies to Question on Verification for Zero Energy State

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OSHA Replies to Question on Verification for Zero Energy State

A recurring question in many of our classes concerns verification for zero energy state, or verifying all energy sources are de-energized. One of our instructors recently contacted Kentucky OSH on this topic and received a formal reply pretty quickly. The complete letter follows:

From: Pettit, Mike (LABOR)
Sent: Wednesday, May 20, 2015 12:53 PM
Subject: Electrical Zero Energy Verification-reply

Dear Mr. Sellars,

The Kentucky Labor Cabinet operates a complete occupational safety and health (OSH) program approved and monitored by the Occupational Safety and Health Administration (OSHA). Your email states:

“Ken Sellars here with E-Hazard in Louisville, KY. We train nationwide on electrical safety, arc flash safety, OSHA 1910 subpart S, and a host of other standards related to electrical safety, both here and in Canada. I have a question that often arises in training sessions and would love to get your official opinion. The issue is regarding verification of zero energy state while performing lockout/tag out/verify an grounding above 600 volts.

In our instructional classes, we always reference NFPA 70E 120.1(5), which says the following: “Use an adequately rated test instrument to test each phase conductor or circuit part to verify it is de-energized. Test each phase conductor or circuit part both phase-to-phase and phase-to-ground. Before and after each test, determine the test instrument is operating satisfactorily through verification on a known voltage source.” The NFPA 70E standard does NOT give a voltage range that this rule would apply to, but does list in the Informational Note to see ANSI/ISA 61010-1, which references voltage measurement and test instruments intended for use on electrical systems 1000 volts and below.

Most clients that I have taught for, both in the industrial and utility setting, use a High Voltage Proximity detector similar to the Salisbury 4544 with pre- and post-checks to verify functionality. OSHA of course states  in 1910.269(n)(5) Testing that “The employer shall ensure that, unless a previously installed ground is present, employees test lines and equipment and verify the absence of nominal voltage before employees install any ground on those lines or that equipment.” The METHOD of performing this step is left to the employer and/or workers performing the lockout/tag out/verify and ground sequence.

So the question at hand is this: Is the use of a properly-rated proximity voltage detector allowed and considered by OSHA to be the correct method of verifying zero energy prior to the application of grounds on a system rated higher than 600 volts? The situation in question almost always involves a maintenance activity where workers WILL be contacting the electrical parts once locked out and grounded for repair/maintenance/cleaning. Is this method permissible, or should the employer be providing a voltage-rated contact meter that can actually test both phase-to-phase and phase-to-ground voltage prior to the application of worker safety grounds?

Note that even some of the best high voltage contact meters are accurate to 1%, which on a 15KV system would still allow for a non-indicated voltage of 150 volts phase-to-phase or 75 volts phase-to-ground prior to the application of ground sets, which is why we always instruct electrical workers to use voltage-rated gloves and hot sticks to apply and remove safety grounds.

Any guidance here would be greatly appreciated and would be a great help in our goal to maintain an electrically-safe workforce. Thank you in advance for your time and consideration.”


The Kentucky OSH Program does not specify a method to verify that circuits are de-energized, only that it be done.  Voltage proximity meters may be an acceptable means to verify that circuits are de-energized provided they verify the absence of nominal voltage.

If the work is outside the scope of 29 Code of Federal Regulations (CFR) 1910.269, then 29 CFR 1910-Subpart S applies.  29 CFR 1910.333(b)(2)(iv), adopted by Kentucky Administrative Regulation 2:318, states:

“The requirements of this paragraph shall be met before any circuits or equipment can be considered and worked as de-energized.

29 CFR 1910.333(b)(2)(iv)(B) states:

“A qualified person shall use test equipment to test the circuit elements and electrical parts of equipment to which employees will be exposed and shall verify that the circuit elements and equipment parts are de-energized.  The test shall also determine if any energized condition exists as a result of inadvertently induced voltage or unrelated voltage back fed even though specific parts of the circuit have been de-energized and presumed to be safe.  If the circuit to be tested is over 600 volts, nominal, the test equipment shall be checked for proper operation immediately before and immediately after this test.”

As you know, there are many different types of electrical equipment for different types of electrical work.  The Subpart S standard dealing with test instruments and equipment is 29 CFR 1910.334(c)(3).  It states:

“Test instruments and equipment and their accessories shall be rated for the circuits and equipment to which they will be connected and shall be designed for the environment in which they will be used.”

The National Electrical Safety Code-2012 and NFPA 70E-2015 can be used by employers as a guide in making assessments and equipment selections required by the standard.

Another standard that may be applicable is 29 CFR 1910.132, as adopted by 803 KAR 2:308.  It requires each employer to assess the workplace to determine if hazards are present, or likely to be present, which necessitate the use of personal protective equipment (PPE).  If such hazards are present, or likely to be present, appropriate PPE must be selected and used.

For your information, the Kentucky OSH Program’s Division of Education and Training (E&T) is available by an employer’s invitation to provide an onsite consultative survey or technical assistance visit to advise what is needed to meet applicable OSH requirements.  A consultative survey is a courtesy workplace evaluation conducted at the request of an employer or employer representative. The purpose of a survey is to encourage and assist employers in providing a safe workplace for their employees by identifying workplace hazards and violations of Kentucky OSH Program standards. Surveys are conducted by Division of E&T occupational safety and health consultants who are experienced in technical areas such as electrical safety, fire protection, confined space entry, indoor air quality, and industrial hygiene. The consultants are available to visit your workplace and identify safety and health hazards; or, in the case of a technical assistance visit, evaluate specific safety and health matters.

Although the format and objective of a compliance inspection and a consultative survey are basically the same, there are significant differences, such as:

  • A consultative survey is conducted by the Division of E&T only upon written request by the employer or authorized company representative, whereas an enforcement inspection is conducted by the Division of Compliance without prior notice to the employer;
  • Monetary penalties are not assessed for hazards identified by a consultant during consultative surveys; however, the employer agrees to correct all “SERIOUS HAZARDS” identified, whereas violations identified by the compliance officer may result in citations which have to be corrected and may be accompanied by penalties. Failure to correct “SERIOUS HAZARDS” identified during a consultative survey within the prescribed period of time could result in their referral to the Division of Compliance;
  • All results of a survey are considered confidential in that the Division of Compliance doesn’t have access to these files unless the employer refuses to correct any serious hazards identified during the survey; and,
  • Employers are encouraged to have employee involvement in consultative surveys and discussion of the hazard.

The Division of Compliance and the Division of E&T function independently of one another without sharing information relative to their activities. Therefore, a request for a consultative survey, or any other service from the Division of E&T, neither increases nor decreases the possibility of a compliance inspection.

These, and many other Division of E&T services, are offered at no cost to the employer. You may contact the Director of the Division of E&T at (502) 564-3536 to discuss those services.  Employers may expedite the consultative survey process by reviewing information at www.labor.ky.gov/osh/cons.htm. ¹

If you have additional questions or need further clarification, please call me at 502 564-4069.


Mike Pettit, Safety Standards Specialist
Department of Workplace Standards
Kentucky Labor Cabinet
1047 US HWY 127 South
Suite 4
Frankfort KY 40601

(We recently posted a burning question on the use of proximity detectors. You can read that post here.)

¹Web link to KY Labor Cabinet’s Division of Education & Training

Have a question about electrical safety and standards?   

Hugh Hoagland

does research and testing of PPE exposed to electrical arcs and is an arc flash expert. Hugh is a Sr. Consultant at ArcWear and Sr. Partner at e-Hazard. Read more about Hugh.

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