GFCI protection for portable-generator receptacles

August 24, 1977
Mr. R. D. Salzwedel
Director of Safety
CIAF Corp.
[Recipient address omitted]
Dear Mr. Salzwedel:
This is in response to your letter dated March 1, 1977, requesting clarification of the requirements in using ground fault circuit interrupters (GFCI) on portable generators, other than the type specified in the existing standard.
In the case of the GFCI option, the standard addresses receptacles not generators. All 120-volt, 15 and 20 ampere receptacles, other than those noted in the exception, which are not part of the permanent wiring and which are in use on construction sites must be protected. Therefore, when it is in use by an employee on a construction site, a 120-volt, 15 or 20 ampere receptacle powered by a portable or vehicle-mounted generator, which is not a two-wire generator, or which is rated more than 5kw must be protected by a GFCI.
If I may be of further assistance, please feel free to contact me.
Sincerely,
John K. Barto,
Chief
Division of Occupational Safety Programming

[Earlier referral letter reproduced on OSHA page; omitted here.]