On December 22, 2016, the Occupational Safety and Health Administration (OSHA) issued a memorandum that extends the enforcement date of the minimum approach distance requirements to July 1, 2017 and accepts a paper recently published by the Institute of Electrical and Electronics Engineers (IEEE) as guidance regarding the calculation of maximum transient overvoltages that employers can follow to comply with the minimum approach distance requirements.
The minimum approach distance requirements (29 CFR 1910.269(l)(3)(i), (ii) or 29 CFR 1926.960(c)(1)(i), (ii), as applicable), which revise the general industry and construction standards for work on electric power generation, transmission, and distribution installations, will be enforceable starting on July 1, 2017. OSHA does not expect any further delays to the enforcement of the requirements, as the previous two delays were due to the absence of peer-reviewed guidance regarding the calculation of maximum transient overvoltages and such guidance has since been published by the IEEE and has now been accepted by OSHA.
The IEEE paper entitled “Practical Approaches to Reducing Transient Overvoltage Factors for Live Work” describes practices that can be adopted to reduce maximum transient overvoltages to “industry-accepted values” given in IEEE Standard 516-2009.
OSHA’s memorandum states that, when live work is done on electric power systems operating at over 72.5kV, employers can do the following to comply with the minimum approach distance requirements: (1) follow the guidance in the IEEE’s paper, (2) use the maximum transient overvoltage values identified by the IEEE and listed in Table A of the memorandum to calculate minimum approach distances, so long as six conditions specified in the memorandum are in place, and (3) use the minimum approach distances listed in Table B of the memorandum, so long as the conditions listed in the memorandum apply and the employer follows the three notes to Table B. Alternatively, employers must establish minimum approach distances in accordance with 29 CFR 1910.269(l)(3) or 29 CFR 1926.960(c)(1), as applicable, to comply with the requirement.
OSHA notes that, in most cases, the entity that operates the electric system will implement the required practices. When a contract employer must comply with the minimum approach distance requirements, the entity operating the system and the contract employer must coordinate their work rules and procedures (in accordance with 29 CFR 1910.269(a)(3)(iii) or 29 CFR 1926.950(c)(3), as applicable) so that the practices outlined in the memorandum are followed.