Q: I understand OSHA has made a final announcement on minimum approach distances. Can you explain the latest information?
A: On December 22, 2016, OSHA issued a memorandum to regional administrators regarding the enforcement of minimum approach distance requirements in 29 CFR 1910.269 and 1926 Subpart V (see www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=31079). The memorandum had an effective date of July 1, 2017. Readers will recall that concerns about the rising risks of transient over-voltages were the basis for the increased minimum approach distances published by OSHA in 2014. The bottom line is that OSHA has accepted an industry engineering analysis – an IEEE paper titled “Practical Approaches to Reducing Transient Overvoltages Factors for Live Work” that was delivered at IEEE’s 2016 ESMO conference – as a basis for the final guidance of the memorandum. The guidance for enforcement is simple, but it is divided for above and below 72 kV. Following are the choices spelled out in the memorandum.
New Transient Table
The IEEE paper established a new Table A with standard transient multipliers based on voltage. The employer may still calculate their own minimum approach distances utilizing an engineering analysis approved by the standard using transients published in the new Table A.