Working distance is a critical factor when determining the appropriate level of personal protective equipment (PPE) required for a task involving energized electrical equipment. Often a worker’s hands will be significantly closer to the arc source than the face and body.

The working distance is based on the distance from the workers face and body from the arc source, not where the hands are.

If a task requires a worker to get their face and chest closer to the exposed arc source than the minimum required working distance shown on the equipment label, a greater level of PPE may be required.

The following definitions can be found in Article 100 of NFPA 70E:

Below is a sample of NFPA 70E. For the complete section, see the actual NFPA 70E text at NFPA.ORG. Once there, click on the free access link to NFPA 70E.

Working Distance. The distance between a person’s face and chest area and a prospective arc source.

Informational Note: Incident energy increases as the distance from the arc source decreases. See 130.5(C)(1) for further information.