OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.
July 31, 1984
Mr. Peter J. Schram
Chief Electrical Engineer
National Electrical Code
National Fire Protection Association
Battery March Park
Quincy, Massachusetts 02269
Dear Mr. Schram:
This is in response for an interpretation of cord sets (extension cords) plugged into permanent wiring at construction sites to supply portable electrical hand tools.
Section 305-4(a) of the code requires all 125-volts single-phase, 15 and 20 amperes receptacle outlets which are not a part of the permanent wiring of the building or structure and which are in use by employees shall have ground-fault circuit-interrupter protection for personnel.
I have been advised by my staff that cord sets (extension cords) plugged into permanent wiring at construction sites are temporary wiring and as such require ground-fault protection for personnel on construction sites.
You assistance in this matter will be appreciated.
Sincerely,
John B. Miles, Jr.,
Director
Directorate of Field Operations