February 12, 2013
How To De-Energize Systems Safely Per NFPA 70E
One of OSHA’s main objectives in conducting jobsite audits is to prove employees have the skills, training and PPE necessary to reach a proper de-energized equipment state. As I mentioned in my previous blog article – this single vision is the main goal of NFPA 70E, and the key to a program’s success.
Electricity is dangerous because we cannot use sight or smell to know voltage is no longer present. In order to get equipment to a de-energized state safely, an employee must be able to perform the following steps (steps 3, 4 and 5 are interchangeable) correctly when asked by an Environmental Health and Safety (EHS) Director or an OSHA Compliance Safety and Health Officer (CSHO).
- Identify the correct upstream Lock Out Tag Out (LOTO) source location.
- Apply proper locks and/or tags to isolate the upstream power source(s).
- Verify the rubber insulated gloves are in proper condition (i.e. air inflator, self-test)
- Inspect the condition of leather gloves for adequate physical protection of the rubber insulated gloves.
- Show the electrical meter being used is of the correct rating (Cat III or IV), and that the meter has been tested on a known 120volt source before the LOTO confirmation can proceed.
- Know the arc flash PPE levels for the area you are entering, and always wear appropriate PPE before checking for absence of power or opening the disconnect or enclosure.
- Perform point-on-point terminal tests to ensure absence of power by metering phase-to-phase and phase-to-ground upon entering the enclosure.
- Double-check the meter on the same known source of voltage 120V or less to ensure the meter was functioning correctly following the confirmation step.
If an employee is able to properly execute this safety process, then he or she has demonstrated all the correct arc flash PPE steps needed, and your employee would pass an audit check.
Detailed PPE labeling is vital to successfully completing this process and in turn, an employer’s long term success. Many versions of arc flash labels on a national level often lack details essential for maintenance employees; poor or generic PPE labeling based on software system output creates risk, and opens the door for non-compliant behaviors.
In my next blog post, I will explain the common issues that employees encounter with these steps and how safety programs can be tailored to better support your qualified employees. This fundamental process will become the foundation from which you build your policies around.