Lately there has been a rash of incidents involving flashes and contacts with primary voltage. The incidents occurred due to improperly written switching orders or missed switching steps, none of which were recognized by the workers involved with the tasks. These types of errors have long been a problem and continue to result in numerous injuries and fatalities.
In April 2014, OSHA’s revised 29 CFR 1910.269 standard was published. This was the first revision to the standard in 20 years, and one paragraph in particular that was clarified was paragraph (m), “Deenergizing lines and equipment for employee protection,” which addresses system operations. As of the OSHA update, the employer is now obligated to appoint an employee to be in charge of the clearance issued by the system operator; this employee will have control over and oversight of all switching that affects the performance of the system.
Specifically, OSHA has promulgated the following rules.
If a system operator is in charge of the lines or equipment and their means of disconnection, the employer shall designate one employee in the crew to be in charge of the clearance and shall comply with all of the requirements of paragraph (m)(3) of this section in the order specified.
The employer shall ensure that all switches, disconnectors, jumpers, taps, and other means through which known sources of electric energy may be supplied to the particular lines and equipment to be deenergized are open. The employer shall render such means inoperable, unless its design does not so permit, and then ensure that such means are tagged to indicate that employees are at work.
Electric utilities must establish a clearance – also referred to as an “open air gap” – on all known sources of the system and source voltages. A clearance also should be used to disable all automatic switchgear to ensure that all system voltage has been isolated from the work area. This procedure is regulatory language and required to protect employees. Tags shall be applied to all open points to indicate that employees are at work and nothing shall be re-energized.