Validating your electrical meter BEFORE testing on the isolated circuit

Recently we witnessed an electrical work perform a lockout on a piece of equipment that was not starting during the start-up phase of the process. This piece of equipment was absolutely critical for the process to run safely so this worker and the facility personnel witnessing this as well failed to recognize a CRITICAL mistake he made in his “means to verify a zero energy state”. When I questioned his actions I was met with a lot of pushback, such as “OSHA does not require it” or my favorite… “I’ve been doing this job long before you graduated with your fancy college degree”. What did I witness?

This electrical worker failed to test his voltmeter on a known source, then test the isolated circuit, and then retest his meter on the known source again. Where did I get such a crazy notion that this is part of electrical safety-related work practices?

NEC 70E: Standard for Electrical Safety in the Workplace, 2021 Edition – Chapter 1 Safety-Related Work Practices

120.4(B)(6) Testing.

The procedure shall establish the following:

Test instrument to be used, the required PPE, and the person who will use it to verify proper operation of the test instrument on a known voltage source BEFORE AND AFTER USE
Requirement to define the boundary of the electrically safe work condition
Requirement to test before touching every exposed conductor or circuit part(s) within the defined boundary of the work area
Requirement to retest for absence of voltage when circuit conditions change or when the job location has been left unattended
Planning considerations that include methods of verification where there is no accessible exposed point to take voltage measurements

I will admit that OSHA does not require this in their 31-year-old 1910.335 Safeguards for personnel protection or in 1910.333 Selection and use of work practices but I am not sure why they don’t. I received my very first training on electrical safety-related work practices in 1993 when I was starting my career as a SE in the chemical industry. Heck, arc flash was not even a hot topic yet, but we were all trained to test our meters on a known source BEFORE, and AFTER we used it to verify a ZES on the circuit we were getting ready to work on.

And I will add this, I have had two very senior OSHA CSHO and Asst. AD’s work with me over the years and both of them were fanatics on this matter and said it was indeed citable under 1910.333 Selection and use of work practices.

1910.333(b)(2)(iv)(B) 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 deenergized. The test shall also determine if any energized condition exists as a result of inadvertently induced voltage or unrelated voltage backfeed even though specific parts of the circuit have been deenergized 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 after this test.

I did find this in the OSHA archives…

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