Source: https://www.federalregister.gov/documents/2006/05/17/06-4391/evaluation-of-international-electrotechnical-commissions-standards-for-explosion-proof-enclosures
Timestamp: 2017-11-23 13:40:48
Document Index: 400901688

Matched Legal Cases: ['ART 6', 'ART 18', 'art 0', 'art 1', 'art 11', 'art 0', 'art 1', 'art 0', 'art 1', 'art 7', 'art 18', 'art6', 'art6', '§\u20096', '§\u200918', '§\u20096', '§\u20096', 'art 0', 'art 1', 'arts 7', '§\u20097', '§\u20097', 'art 7', 'art 7', 'art 0', 'art 1', '§\u20097', 'art 51', '§\u20097', '§\u200918', '§\u20096', 'art 6', 'art 18', 'art 18', 'art 0', 'art 1', '§\u200918', 'art 51', '§\u200918', '§\u20097']

Federal Register :: Evaluation of International Electrotechnical Commission's Standards for Explosion-Proof Enclosures
A Rule by the Mine Safety and Health Administration on 05/17/2006
71 FR 28581
28581-28585 (5 pages)
30 CFR 6
1219-AB42
PART 6—TESTING AND EVALUATION BY INDEPENDENT LABORATORIES AND NON-MSHA PRODUCT SAFETY STANDARDS
PART 18—-ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES
https://www.federalregister.gov/d/06-4391 https://www.federalregister.gov/d/06-4391
Final rule; equivalency determination.
MSHA reviewed the requirements of the International Electrotechnical Commission's (IEC) standards for Electrical Apparatus for Explosive Gas Atmospheres to determine if they are equivalent to the Agency's applicable product approval requirements or can be modified to provide at least the same degree of protection as those requirements. MSHA has determined that the IEC's standards for explosion-proof enclosures, with modifications, provide the same degree of protection as MSHA's applicable product approval requirements. Applicants may request that MSHA grant product approval for explosion-proof (flameproof) enclosures based on compliance with the IEC standards provided MSHA's specified list of modifications is also addressed in the submitted design.
Effective Date: This final rule is effective May 17, 2006. The incorporation by reference of certain publications listed in the rule is approved by the Director of the Federal Register as of May 17, 2006.
For information concerning the technical content of the rule, contact David C. Chirdon, Chief Electrical Safety Division, Approval and Certification Center, MSHA, R.R. 1, Box 251 Industrial Park Road, Triadelphia, West Virginia 26059. Mr. Chirdon can be reached at chirdon.david@dol.gov (e-mail), 304-547-2026 (voice), or 304-547-2044 (facsimile). For information concerning the rulemaking process, contact Patricia W. Silvey, Acting Director, Office of Standards, Regulations, and Variances, MSHA, 1100 Wilson Blvd., Arlington, Virginia 22209-3939. Ms. Silvey can be reached at (202) 693-9440.
MSHA maintains a listserve on the Agency's Web site that enables subscribers to receive e-mail notification when MSHA publishes rulemaking documents in the Federal Register. Start Printed Page 28582
To subscribe to the listserve, visit MSHA's Web site at http://www.msha.gov/​subscriptions/​subscribe.aspx. You may obtain copies of this final rule in an alternative format by accessing the Internet at http://www.msha.gov/​REGSINFO.HTM. The document is also available by calling 202-693-9440.
On December 1, 2003, MSHA announced in the Federal Register (68 FR 67216) our intent to review the International Electrotechnical Commission's (IEC) standards for Electrical Apparatus for Explosive Gas Atmospheres, Part 0, General Requirements (IEC 60079-0); Part 1, Electrical Apparatus for Explosive Gas Atmospheres, Flameproof Enclosures “d” (IEC 60079-1); and Part 11, Intrinsic Safety (IEC 60079-11). The Federal Register notice solicited comments concerning the Agency's intent to review the IEC standards.
A 60-day comment period was provided which closed on January 30, 2004. Comments were received from four (4) commenters. Two commenters suggested that MSHA should deem the IEC standards equivalent in their unmodified form and urged us to pursue participation in the international agreement between countries relative to the IEC standards known as the “IECEx Scheme.” The goal of the IECEx Scheme is to facilitate international trade in electrical equipment intended for use in explosive atmospheres (Ex equipment) by eliminating the need for multiple national certifications while preserving an appropriate level of safety. Two commenters suggested additional standards for MSHA to consider reviewing for equivalency in the future. Because these comments are beyond the scope of this equivalency determination, the Agency will not address them here.
MSHA's review of the International Electrotechnical Commission's (IEC) standards for Electrical Apparatus for Explosive Gas Atmospheres, Part 0, General Requirements (IEC 60079-0, Fourth Edition, 2004-01); and Part 1, Electrical Apparatus for Explosive Gas Atmospheres, Flameproof Enclosures “d” (IEC 60079-1, Fifth Edition, 2003-11) is completed. These two IEC standards together describe the overall requirements for design of flameproof enclosures. The IEC 60079-1, Flameproof Enclosures “d” document provides the specific technical design and testing requirements for explosion-proof enclosures while the IEC 60079-0, General Requirements document provides the general application and use specifications for all IEC Electrical Apparatus for Explosive Gas Atmosphere standards. Applicants may request that MSHA grant product approval for explosion-proof (flameproof) enclosures based on compliance with these IEC standards provided our specified list of modifications is also addressed in the submitted design. Start Printed Page 28583
The equivalency review for the IEC standards concerning Electrical Apparatus for Explosive Gas Atmospheres, Part 0, General Requirements and Part 1, Electrical Apparatus for Explosive Gas Atmospheres, Flameproof Enclosures “d” involved comparing them with MSHA's corresponding requirements for explosion-proof enclosures found in 30 CFR part 7—Testing by applicant or third party and part 18—Electric motor-driven mine equipment and accessories.
Specific details of MSHA's findings of the Agency's equivalency review can be obtained from http://www.msha.gov/​Part6SingleSource/​Part6SingleSource.asp or by contacting the Electrical Safety Division, Approval and Certification Center, MSHA, R.R. 1, Box 251, Industrial Park Road, Triadelphia, West Virginia 26059, chirdon.david@dol.gov (e-mail), 304-547-2026 (voice), or 304-547-2044 (facsimile).
This final rule adds § 6.30, MSHA listing of equivalent non-MSHA product safety standards, which lists non-MSHA product safety standards MSHA have evaluated and determined to provide at least the same degree of protection with or without modifications. Subparagraph 6.30(a) specifies the IEC product safety standards reviewed for equivalency to MSHA's explosion-proof enclosure standards and references sections 7.10(c)(1) and 18.6(a)(3)(i) for a list of the required modifications.
Subparagraph (a)(3) of § 18.6, Applications, is amended to include subparagraph (i) and subparagraphs (i)(A) through (i)(I). Subparagraph (i) lists the specific IEC product safety standards and subparagraphs (i)(A) through (i)(I) specify the modifications to the IEC standards required to provide the same degree of protection as MSHA requirements.
2. Add § 6.30 to read as follows:
§ 6.30
MSHA listing of equivalent non-MSHA product safety standards.
(a) The International Electrotechnical Commission's (IEC) standards for Electrical Apparatus for Explosive Gas Atmospheres, Part 0, General Requirements (IEC 60079-0, Fourth Edition, 2004-01) and Part 1, Electrical Apparatus for Explosive Gas Atmospheres, Flameproof Enclosures “d” (IEC 60079-1, Fifth Edition, 2003-11) must be modified in order to provide at least the same degree of protection as MSHA explosion-proof enclosure requirements included in parts 7 and 18 of this chapter. Refer to §§ 7.10(c)(1) and 18.6(a)(3)(i) for a list of the required modifications. The IEC standards may be inspected at MSHA's Electrical Safety Division, Approval and Certification Center, R.R. 1, Box 251, Industrial Park Road, Triadelphia, West Virginia 26059 and may be purchased from International Electrical Commission, Central Office 3, rue de Varembé, P.O. Box 131, CH-1211 GENEVA 20, Switzerland.
4. Amend § 7.10 by revising paragraph (c) to read as follows:
(c) A listing of all equivalency determinations will be published in this Start Printed Page 28584part 7. The listing will state whether MSHA accepts the non-MSHA product safety standards in their original form, or whether MSHA will require modifications to demonstrate equivalency. If modifications are required, they will be provided in the listing. MSHA will notify the public of each equivalency determination and will publish a summary of the basis for its determination. MSHA will provide equivalency determination reports to the public upon request to the Approval and Certification Center. MSHA has made the following equivalency determinations applicable to this part 7.
(1) MSHA will accept applications for motors under Subpart J designed and tested to the International Electrotechnical Commission's (IEC) standards for Electrical Apparatus for Explosive Gas Atmospheres, Part 0, General Requirements (IEC 60079-0, Fourth Edition, 2004-01) and Part 1, Electrical Apparatus for Explosive Gas Atmospheres, Flameproof Enclosures “d” (IEC 60079-1, Fifth Edition, 2003-11) (which are hereby incorporated by reference and made a part hereof) provided the modifications to the IEC standards specified in § 7.10(c)(1)(i) through (ix) are met. The Director of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The IEC standards may be inspected at MSHA's Electrical Safety Division, Approval and Certification Center, R.R. 1, Box 251, Industrial Park Road, Triadelphia, West Virginia 26059 or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html. These IEC standards may be obtained from International Electrical Commission, Central Office 3, rue de Varembé, P.O. Box 131, CH-1211 GENEVA 20, Switzerland.
(i) Enclosures associated with an electric motor assembly shall be made of metal and not have a compartment exceeding ten (10) feet in length. External surfaces of enclosures shall not exceed 150 °C (302 °F) in normal operation.
(ii) Enclosures shall be rugged in construction and should meet existing requirements for minimum bolt size and spacing and for minimum wall, cover, and flange thicknesses specified in paragraph(g)(19) of § 7.304 Technical requirements. Enclosure fasteners should be uniform in size and length, be provided at all corners, and be secured from loosening by lockwashers or equivalent. An engineering analysis shall be provided for enclosure designs that deviate from the existing requirements. The analysis shall show that the proposed enclosure design meets or exceeds the mechanical strength of a comparable enclosure designed to 150 psig according to existing requirements, and that flamepath clearances in excess of existing requirements will not be produced at an internal pressure of 150 psig. This shall be verified by explosion testing the enclosure at a minimum of 150 psig.
(iii) Enclosures shall be designed to withstand a minimum pressure of at least 150 psig without leakage through any welds or castings, rupture of any part that affects explosion-proof integrity, clearances exceeding those permitted under existing requirements along flame-arresting paths, or permanent distortion exceeding 0.040-inch per linear foot.
(v) The minimum lengths of the flame arresting paths, based on enclosure volume, shall conform to those specified in existing requirements to the nearest metric equivalent value (e.g., 12.5 mm, 19 mm, and 25 mm are considered equivalent to 1/2 inch, 3/4 inch and 1 inch respectively for plane and cylindrical joints). The widths of any grooves for o-rings shall be deducted in measuring the widths of flame-arresting paths.
(vi) Gaskets shall not be used to form any part of a flame-arresting path. If o-rings are installed within a flamepath, the location of the o-rings shall meet existing requirements.
6. Amend § 18.6 by revising paragraph (a)(3) to read as follows:
(3) An applicant may request testing and evaluation to non-MSHA product safety standards which have been determined by MSHA to be equivalent, under § 6.20 of this chapter, to MSHA's product approval requirements under this part. A listing of all equivalency determinations will be published in 30 CFR part 6 and the applicable approval parts. The listing will state whether MSHA accepts the non-MSHA product safety standards in their original form, or whether MSHA will require modifications to demonstrate equivalency. If modifications are required, they will be provided in the listing. MSHA will notify the public of each equivalency determination and will publish a summary of the basis for its determination. MSHA will provide equivalency determination reports to the public upon request to the Approval and Certification Center. MSHA has made the following equivalency determinations applicable to this part 18.
(i) MSHA will accept applications for explosion-proof enclosures under part 18 designed and tested to the International Electrotechnical Commission's (IEC) standards for Electrical Apparatus for Explosive Gas Start Printed Page 28585Atmospheres, Part 0, General Requirements (IEC 60079-0, Fourth Edition, 2004-01); and Part 1, Electrical Apparatus for Explosive Gas Atmospheres, Flameproof Enclosures “d” (IEC 60079-1, Fifth Edition, 2003-11) (which are hereby incorporated by reference and made a part hereof) provided the modifications to the IEC standards specified in § 18.6(a)(3)(i)(A) through (I) are met. The Director of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The IEC standards may be inspected at MSHA's Electrical Safety Division, Approval and Certification Center, R.R. 1, Box 251, Industrial Park Road, Triadelphia, West Virginia 26059 or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html. These IEC standards may be obtained from International Electrical Commission, Central Office 3, rue de Varembé, P.O. Box 131, CH-1211 GENEVA 20, Switzerland.
(A) Enclosures shall be made of metal and not have a compartment exceeding ten (10) feet in length. Glass or polycarbonate materials shall be the only materials utilized in the construction of windows and lenses. External surfaces of enclosures shall not exceed 150 °C (302 °F) and internal surface temperatures of enclosures with polycarbonate windows and lenses shall not exceed 115 °C (240 °F), in normal operation. Other non-metallic materials for enclosures or parts of enclosures will be evaluated, on a case-by-case basis, under the new technology provisions in § 18.20(b) of this part.
(B) Enclosures shall be rugged in construction and should meet existing requirements for minimum bolt size and spacing and for minimum wall, cover, and flange thicknesses specified in paragraph (g)(19) of § 7.304 Technical requirements. Enclosure fasteners should be uniform in size and length, be provided at all corners, and be secured from loosening by lockwashers or equivalent. An engineering analysis shall be provided for enclosure designs that deviate from the existing requirements. The analysis shall show that the proposed enclosure design meets or exceeds the mechanical strength of a comparable enclosure designed to 150 psig according to existing requirements, and that flamepath clearances in excess of existing requirements will not be produced at an internal pressure of 150 psig. This shall be verified by explosion testing the enclosure at a minimum of 150 psig.
(C) Enclosures shall be designed to withstand a minimum pressure of at least 150 psig without leakage through any welds or castings, rupture of any part that affects explosion-proof integrity, clearances exceeding those permitted under existing requirements along flame-arresting paths, or permanent distortion exceeding 0.040-inch per linear foot.
(E) The minimum lengths of the flame arresting paths, based on enclosure volume, shall conform to those specified in existing requirements to the nearest metric equivalent value (e.g., 12.5 mm, 19 mm, and 25 mm are considered equivalent to 1/2 inch, 3/4 inch and 1 inch respectively for plane and cylindrical joints). The widths of any grooves for o-rings shall be deducted in measuring the widths of flame-arresting paths.
(I) Special explosion tests are required for explosion-proof enclosures that share leads (electric conductors) through a common wall with another explosion-proof enclosure. These tests are required to determine the presence of pressure piling conditions in either enclosure when one or more of the insulating barriers, sectionalizing terminals, or other isolating parts are sequentially removed from the common wall between the enclosures. Enclosures that exhibit pressures during these tests that exceed those specified in existing requirements must be provided with a warning tag. The durable warning tag must indicate that the insulating barriers, sectionalizing terminals, or other isolating parts be maintained in order to insure the explosion-proof integrity for either enclosure sharing a common wall. A warning tag is not required if the enclosures withstand a static pressure of twice the maximum value observed in the explosion tests.