The NFPA and OSHA regulations stipulate that service and maintenance work should be done on de-energized equipment.
"Hot" work, that is working on equipment in an energized state is allowed by both OSHA and NFPA under strict guidelines.
Use a written permit system for planning and conducting work on or near energized parts. A permit contains the following information:
- Why and how the work will be conducted.
- Detailed information about the shock and flash hazards involved:
- EHA required on all circuits 50V or higher
- Safe work practices to be used.
- Personal protective equipment (PPE) to be used.
- Authorization for the energized work (signatures).
- The approach boundaries defined.
- Circuit and equipment description/ location.
- Preliminary job briefing record.
- Worker training and certification documented.
- Arc flash risk assessments.
- Access restrictions (barriers) to be used.
Click on the link below to view a sample Energized Electrical Work Permit:
Energized Electrical Work Permit
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Energized Work Is Permitted When
- When the employer demonstrates that it is not possible to power down because of an increased hazard.
- Is deemed infeasible by the employer due to the design of equipment or limitations in operation.
- Working on equipment less than 50 volts.
- Under normal operation (the risk associated is acceptable) when the equipment:
- has been properly installed to industry codes and standards.
- has been maintained properly to manufacturer's. recommendations and industry standards and codes.
- has all doors are closed and secured.
- has all covers in place and secured.
- has no evidence of "impending" failure such as arcing, overheating, loose damaged or deteriorating parts.
Exemptions to Needing a EEWP When Performing Energized Work
Work performed within the limited approach boundary of energized electrical conductors or circuit parts by qualified persons (or an un-qualified person under continual escort by a qualified person), utilizing safe work practices and proper PPE, related to the following tasks:
- Testing, troubleshooting voltage/current measurements
- Thermography and visual inspection techniques are used
- General housekeeping duties (non-electrical tasks) outside the restricted approach boundary
- Accessing an area outside the restricted approach boundary if no electrical work is done
Figure 1: Workers Discussing Work Permit
NFPA 70E 2015 Article 130.2(B)(1) Energized Electrical Work Permits.
When Required: When energized work is permitted in accordance with 130.2(A), and energized electrical work permit shall be required under the following conditions:
(1) When work is performed within the restricted approach boundary
(2) When the employee interacts with the equipment when conductors or circuit parts are not exposed but an increased likelihood of injury from an exposure to an arc flash hazard exists.
OHSA CFR 1910.333(c)(2) states that:
"Only qualified persons may work on electric circuit parts or equipment that have not been de-energized…Such persons shall be capable of working safely on energized circuits and shall be familiar with the proper use of special precautionary techniques, personal protective equipment, insulating and shielding materials, and insulated tools."
Figure 2: Applicable Standards