한국어

Part 1: Electrical testing safety - Preparing for absence of voltage testing

전기, 안전
Part 1: Electrical testing safety - Preparing for absence of voltage testing | Fluke
Figure 1. Use a non-contact voltage tester for your first test.

OSHA and the NFPA 70E Standard for Electrical Safety in the Workplace both direct workers to deenergize all energized parts to which an employee may be exposed, unless energized conditions are required for troubleshooting.

Placing electrical equipment or systems in an electrically-safe work condition might seem simple, but there are several factors to consider.

  • Proper planning and preparation will make any type of testing simpler and safer.
  • Perform a risk assessment. A risk assessment is required by NFPA 70E Section 110.1(G) Electrical Safety Program, 130.3 Working While Exposed to Electrical Hazards, 130.4(A) Shock Risk Assessment and 130.5 Arc Flash Risk Assessment. NFPA 70E does not use the phrase "hazard/risk analysis" anymore. The definition of risk assessment in Article 100 incorporates determining the hazards.
  • Having to stop work to fetch other tools or test instruments interrupts focus and can contribute to an accident.
  • Traffic in the area can pose a substantial hazard. This includes foot traffic, as well as forklifts and other type of vehicles. Barriers, barricades, signs and possibly an attendant may be needed to prevent intrusion into the work zone.
  • Complete an Energized Electrical Work Permit (EEWP). This is required by NFPA 70E Section 130.2(B) Energized Electrical Work Permit. The EEWP incorporates the risk assessments needed, details the required PPE, as well as the precautions needed to protect the work zone. It also contains an authorization to perform energized work, which is critical to worker safety. Management must approve all energized work prior to the task, as they are responsible if an incident should occur.
  • NFPA 70E has expanded the exemptions for the use of an EEWP in Section 130.1(B)(3), but those exemptions only relieve the worker of having the EEWP signed off by management. All other requirements of Article 130 still apply.
  • Informative Annex J contains an example EEWP. Since it is located in the annex it can be modified as needed to suit a specific task or job condition.

Before taking a single measurement, first determine:

  • Is this troubleshooting or testing for the absence of voltage?
  • What test instruments are required to verify the energized or de-energized state?
  • Is a safety backup required? Has he/she been trained in the proper methods of release, how to contact emergency assistance or CPR/use of an AED? Where is the location of the nearest AED?
  • Where will the safe work zone be established? Will it be at the limited approach boundary or the arc flash boundary?
  • What Personal Protective Equipment (PPE) will be required?
  • What is the voltage of the circuit?
  • What is the arc flash boundary?
  • How much incident energy is possible at your working distance?