Frame grounding of arc welding machines. | Occupational Safety and Health Administration

Standard Number:

1926.351

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.

April 2, 1993

Mr. C. J. Beysselance
Regional Safety Manager
Jacobs Engineering Group, Inc.
P.O. Box 98033
Baton Rouge, Louisiana 70898

Dear Mr. Beysselance:

Your June 2 letter to Robert D. Holmes, Occupational Safety and Health Administration (OSHA) Area Director, requesting an interpretation of OSHA's standards addressing frame grounding of arc welding machines (1926.351(c)(5)(iv)) has been referred to the Office of Construction and Maritime Compliance Assistance for response. I apologize for the delay in responding to your inquiry.

As you know, OSHA's construction requirements for frame grounding of arc welding machines at 29 CFR 1926.351(c)(5) do not specifically address engine-driven units. In the absence of a specific grounding requirement and because an engine-driven arc welding machine is basically a portable generator, OSHA would consider compliance with 1926.404(f)(3) as compliance with the welding requirements at 1926.351(c)(5).

If we can be of any further assistance, please contact me or Mr. Dale Cavanaugh at (202) 219-8136.

Sincerely,

Roy F. Gurnham, Esq., P.E.
Director
Office of Construction and Maritime
Compliance Assistance

August 5, 1992

MEMORANDUM FOR:  PATRICIA K. CLARK
                Director 
                Directorate of Compliance Programs

THROUGH:         LEO CAREY 
                Director 
                Office of Field Programs

SUBJECT:         Requests for Interpretation Re:  29 CFR 1910.254(c)(2)(i)
                and 29 CFR 1926.351(c)(5)(iv)

The attached request for subject interpretations was received by our Baton Rouge Area Office from Jacobs Engineering Group, Inc, Baton Rouge, Louisiana.

This inquiry is forwarded for your review and response since the interpretations could have national implication for consistency in enforcement activities.

Please provide a copy of your response to Jerry Bailey, Assistant Regional Administrator for Technical Support.

GILBERT J. SAULTER
Regional Administrator

Attachments

August 5, 1992

Mr. C. J. Beysselance
Regional Safety Manager
Jacobs Engineering Group, Inc.
P. O. Box 98033
Baton Rouge, Louisiana 70898

Dear Mr. Beysselance:

This refers to your letter of June 2, 1992, addressed to our Baton Rouge Area Office, concerning clarification of OSHA safety standards [29 CFR 1910.254(c)(2)(i) and 29 CFR 1926(c)(5)(iv)].

Your inquiry has been referred to the Directorate of Compliance Programs, Washington, D. C., for response at that level.

Please accept our apology for the delay in responding to your request.

Sincerely,

GILBERT J. SAULTER
Regional Administrator

U. S. DEPARTMENT OF LABOR
OCCUPATIONAL SAFETY AND
HEALTH ADMINISTRATION
2156 Wooddale Boulevard
Suite 200
Baton Rouge, Louisiana 70806-1486

June 16, 1992

MEMORANDUM FOR:  Gilbert J. Saulter
                Regional Administrator

ATTENTION:       Jerry D. Bailey 
                ARA/TS

SUBJECT:         Request for Interpretation/Clarification of 29 CFR
                1910.254(c)(2)(i) and 29 CFR 1926.351(c)(5)(iv) 

Re:              Jacobs Engineering Group, Inc.  Baton Rouge, LA

A recent inquiry (copy attached) received from Jacobs Engineering Group, Inc., a Louisiana firm engaged in both construction work and contract maintenance work in chemical plants/refineries, requested a clarification of when grounding of the frame or case of arc-welding machines is required. 1910.254(c)(2)(i) requires grounding of welding machine frames, but exempts engine-driven machines. 1926.351(c)(5)(iv) requires the frames of all are welding and cutting machines to be grounded, either through a third wire in the power cable or through a separate wire grounded at the source of the current, but this paragraph seems to apply to welding machines connected to an electrical supply system and not engine-driven machines.

ANSI/ASC Z 49.1 - 1983, Article 11.4.3 "Machine Frame Grounding" stated "....special attention shall be given to safety grounding connections of portable machines per NFPA 70-Art. 250 "grounding".

ANSI C33.2 - 1972, paragraph 14.2 "transformer type arc-welding machines" states "....An arc-welding machine which is not provided with a flexible cord or cable and is not designed for the connection of wiring system shall be provided with a suitable pressure wire connection for attachment of the grounding conductor".

Article 630 (C) of the National Electric Code "Motor-Generator Arc-Welders" does not mention machine frame grounding.

Since the OSHA standards are worded rather confusingly, we would appreciate your help in clarifying when "machine frame grounding" of arc-welding machines is required. Specifically, what types of portable welding machines require the machine to be grounded and are engine-driven machines exempt from this requirement?

We look forward to you rapid response to the technical questions so we may provide competent guidance to our field personnel. If you have a questions concerning this request, please contact W.A. Womack, Safety Supervisor, in the Baton Rouge Area Office.

ROBERT D. HOLMES
Area Director

Attachments

June 2, 1992

Dear Mr. Holmes,

I am writing to request your assistance in applying current OSHA safety standards to the use of portable welding machines. Specifically, is the frame of a portable engine driven welding machine required to be earth grounded?

Standard 1910.254(c)(2)(i) requires grounding of welding machines but exempts engine-driven machines. Standard 1910.254(d)(3) requires grounding of welding machines frames to be checked and mandates special attention to the "ground connections of portable machines." Standard 1926.351(c)(5) discusses grounding of ARC welding machine frames but is worded rather confusing and I have gotten various interpretation from several electrical experts. Finally, I have a manufacturer's manual (attached) which states that their portable welding machines do not require the machine frame to be grounded.

Your help in clarifying this rather confusing issue is greatly appreciated. If any further information would be helpful, please don't hesitate to call me at 768-5123.

Your friend in safety,

C.J. Beysselance
Regional Safety Manager