UL-508-BULLETINS-2003.pdf

Subject 508 (in reply, refer to Subject 508) 12 Laboratory Drive Research Triangle Park, NC 27709 August 28, 2003 TO: Standards Technical Panel (STP) for Industrial Control Equipment, STP 508; Subscribers to ULs Standards Service for Industrial Control Equipment SUBJECT: Comments and Substantive Changes received on the ANSI Canvass of the February 25, 2003 Meeting Report for the Seventeenth Edition of the Standard for Industrial Control Equipment, UL 508; SUMMARY OF TOPICS The attached comment matrix contains the comments received on the February 25, 2003 meeting report, responses to comments, and substantive changes resulting from those comments. Substantive changes have been proposed for the following topics included in the UL 508 meeting report: Topic I I: Switches With Identified “OFF Position Topic 13: Printed Wiring Board Abnormal Test Topic 18: Supported And Unsupported Enclosure Surfaces Topic 27: Float Operated Switch Type Rating COMMENTS DUE: September 25,2003 The attached comment matrix provides the comment dispositions from the canvass of the meeting report dated February 25, 2003. The ballots were due to the Secretary by April 28, 2003. A follow-up letter was sent to the STP dated May 1, 2003 with ballots due by May 15, 2003. The matrix contains all of the comments that were received. The effective dates are the same as stated in the meeting report dated February 25, 2003 unless noted otherwise. If you wish to change your vote in light of the dispositions/actions or the proposed changes, please respond to us in writing by September 25, 2003. If we do not hear from you by this date, your original vote will be maintained. SUBJECT 508 -2- AUGUST 28,2003 UL has determined that initial consensus has been achieved for items 6, 7, IO, 12, 13, 14, 15A, 15B, 15C, 16, 18, 19, 20, 21, 23, and 25 regarding the ANSI approval of the proposed revisions to UL 508. Items 4, 5, 8, and 9 failed to reach consensus by approval of at least a majority of the membership. As such, these items may be reballoted in the next revision cycle. Items 11 and 27 may be adopted based upon the outcome of the proposed revisions in this bulletin. If the STP concurs with the dispositions/ actions and proposed revisions and consensus is achieved, UL plans to adopt the revised version of UL 508 as an ANSI standard. You have the right to appeal this action on a procedural basis through ULs Appeals Process. If you wish to appeal, please respond by September 25, 2003. Guidelines on how to register an appeal can be obtained on http:/ulstandardsinfonet.ul.com or by contacting the STP Secretary. UL appreciates the time and effort you have put forth to review this standard, and look forward to your continued participation in this UL/ANSI standard activity. UNDERWRITERS LABORATORIES INC. REVIEWED BY: WARREN CASPER JOHN THOMPSON Secretary for STP 508 Chair for STP 508 Standards Department Global Standards RESEARCH TRIANGLE PARK DIVISION RESEARCH TRIANGLE PARK DIVISION Phone: (91 9) 549-1 543 Phone: (91 9) 549-1 621 Fax: (919) 547-6185 Fax: (919) 547-6251 E-mail: Christopher.W.Casperus.ul.com E-mail: john.thompsonus.ul.com http:/ulstandardsinfonet.ul.com Copyright O 2003 Underwriters Laboratories Inc. SR: SAB SUBJECT 508 -Al- AUGUST 28,2003 APPENDIX A COMMENTS MATRIX The Table below provides the comment dispositions from the Ballot of BSRIUL 508, meeting report dated February 25,2003. The Standard for Industrial Control Equipment. STP Secretary: Warren Casper, Phone: (91 9) 549-1 543, Fax: (91 9) 547-61 85, E-mail: Christopher.W.Casperus.ul.com STP Chair: John Thompson, Phone: (919) 549-1621 The columns in the comment resolution matrix can be defined as follows: Comment Submitter Para. # / Text Ref. Comment Action Name of person who submitted comment. Indicates the specific reference for the comment This comment matrix presents a summary of the comment and the suggested wording of proposals. The action, such as accepted or disagree, and the justification for the action, if needed. Disposition The disposition such as resolved or unresolved. SUBJECT 508 -A2- AUGUST 28,2003 Topic 6: Enclosure Types 3RX, 3SX, and 3X Comment Submitter Brian Rock Hubbell Incorporated Paragraph I Text Reference Table 6.7, 6.5.5, 5.15.1.1, 6.15.5, 6.15.6, 5.15.7, 6.15.12, 7.2.1, 3.4, 8.7, 11.3, 11.4, 11.6, 11.8, 11.10, 11.13, and 25.6.6 Comment or Comment Summary I fully concur with the inclusion of Enclosure Types 3X, 3SX, and 3RX in UL 508, as proposed. Furthermore, I support UL's position that the Enclosure Type rating reflects the performance of the enclosure itself in the context of the proposed paragraphs, particularly with regard to Type 3R. As with any INDIVIDUAL product bearing an Enclosure Type rating, it is a component in a complete assembly of products wherein EACH component comprising that TOTAL enclosure installation must have the same or better Enclosure Type rating to maintain the integrity of that Enclosure Type rating. The issue of ventilation of Type 3RX has no different impact on internal components than for a Type 4X enclosure with a Type 4X Listed “breather“ fitting; this Type 4X “breather“ fitting is evaluated and Listed to resist ingress of Type 4 hosedown water and to resist corrosion but intentionally allows passage of moisture-laden air, typically to allow internal humidity to escape from the Type 4X installation rather than becoming entrapped condensate. If there is concern about components fully internal to the enclosure in a particular installation, they too can be selected from those also so rated for corrosion resistance. Addition of Enclosure Types 3X, 3SX, and 3RX in NEMA Standard 250 and in NEC Table 430.91 was based upon ample field history in humid climates where typically Type 3R enclosures in particular have rusted to the point of compromising electrical enclosure integrity while the electrical circuits inside remained functional, energized and accessible to personal contact through deteriorated, unmaintained enclosure ruptures. While this Table 430.91 within the context of the NEC is entitled “Motor Controller Enclosure Selection“, installations require coordination of Enclosure Type ratings for other components (fittings, interconnects, switches, etc.) attached to the electrical enclosure to maintain the environmental enclosure. As indicated in UL 508 Paragraph 6.8.3 (“Openings shall be filled by devices with suitable environmental ratings as specified in Table 6.7.“) and Table 6.7 (“Openings shall be closed by equipment rated for enclosure types“), other UL Standards, beyond UL 508, for these other products also directly reference UL 50 for Enclosure Type requirements. Accordingly, requirements and definition of Enclosure Types 3X, 3RX, and 3SX belona first and foremost in UL 50. ActionlDisposition UL is aware of the new type ratings and intends to propose these in the next proposal bulletin to STP 50. Table Continued on Next Page SUBJECT 508 Zomment or Comment Summary Wirrnative editorial comment: The Exception -A3- ActionlDisposition This requirement AUGUST 28,2003 Table Continued Comment or Comment Summary I Comment Submitter Paragraph l Text I Reference While my STP 508 Ballot is voted as affirmative, it is so with the expectation as a member of both STP 508 and STP 50 that UL 50 will also incorporate requirements and definition of Enclosure Types 3X, 3RX, and 3SX in a timely manner as new business. Topic 9: Float Switches for Use With Sump Pumps Comment Submitter Chip Pudims Bryant Division - Hubbell Incorporated Paragraph l Text Reference 108.1, Exception ActionlDisposition ncludes the text and receptacle. I am not 'amiliar with this product, but do cord-connected loat switches include a receptacle or is this an ?ditoria1 erro0 If it is the latter, I do not have my problem with the proposal. applies to a float switch that is attached as a pendant to a plug and receptacle combination. The receptacle is provided to receive the attachment plug of a cord-connected sump pump. As this proposal did not obtain consensus by a majority of the current STP members, this proposal may be resubmitted to be included in a future revision cycle. Consensus must be achieved before proceeding to adopt proposals as ANSI/UL requirements. Table Continued on Next Page SUBJECT 508 National Electrical Code 430.42(C) talks of a motor connection by means of ”an attachment plug and receptacle” and NEC 430.109(F) requires as one possible form of disconnect to be ”a horsepower-rated attachment plug and receptacle” for the COMPLETE installation. The receptacle would be pari of or installed on the equipment into which the plug-in cord-connected float switch connects rather than on the float switch itself. It would be unreasonable to expect the receptacle to be furnished with the cord-and- -A4- This requirement applies to a float switch that is attached as a pendant to a plug and receptacle combination. The receptacle is provided to receive the attachment plug of a cord-connected sump pump. UL agrees that larger gauge cord would AUGUST 28,2003 Table Continued Comment Submitter Brian Rock Hubbell Incorporated Paragraph I Text Reference 108.1, Exception ActionlDisposition I Comment or Comment Summary plug-connected float switch.As presently proposed, the cord size is limited solely to 18 AWG when rated not more than 7.2 FLA and limited solely to 16 AWG when rated not more than 9.8 FLA. Why not permit LARGER cord sizes if the manufacturer so chooses. Suggested Revision By Commenter for Proposed Exception to 108.1: A cord-connected float switch provided with a 15A attachment plug intended for use with single phase thermally protected sump pumps shall be: a) Provided with m a cord of 18 AWG em4 or laraer when rated not more than 7.2 FLA, or provided with m a cord of 16 AWG em4 or laraer when rated not more than 9.8 FLA; and b) Marked as in 116.3. also be acceptable. However, as the basic requirement, 25.6.1.4, referenced from 108.1, requires a cord of 14 AWG for use with a 15 attachment plug, the exception to 108.1 only needs to be revised to permit 16 AWG in addition to 18 AWG for devices rated not more than 7.2 FLA. As this proposal did not obtain consensus by a majority of the current STP members, this proposal may be resubmitted to be included in a future revision cycle. Consensus must be achieved before proceeding to adopt proposals as ANSI/UL reauirements. Topic 11 : Switches With Identified ”OW Position SUBJECT 508 -A5- AUGUST 28,2003 Comment Submitter Chip Pudims Bryant Division - Hubbell Incorporated Brian Rock Hubbell Incorporated Paragraph I Text Reference 16.7 16.7 Comment or Comment Summary NEMA and individual 5WD member companies objected to the November 26, 2002 UL 20 bulletin because it expanded the scope of the revision to the 2002 NEC Article 404.15(8) to include a mandatory marking requirement. UL has agreed to rewrite the proposal in accordance with the following NEMA suggestion, making only editorial revisions: Switches that are marked OFF shall completely disconnect all ungrounded conductors in the circuit, when in the OFF position. EXAMPLE: Switches that incorporate in-line components, such as neon indicators that pass current through the load in the OFF position, shall not be marked OFF. As suggested at the November 11-12, 2002 UL 508 STP meeting, proposal 11 should be coordinated with the UL 20 standards revision. The UL 508 proposal could read as follows: A switch intended for mounting in an outlet box and with an identified “off“ function, such as “OFF“ or “O“ switch position, shall be constructed such that when the switch is in the “off“ mode, all ungrounded conductors are completely opened by means of an air gap between the line and load terminals. For example: Switches incorporating in-line components, such as a neon indicator, shall not be marked “OFF“ or “O“. The November 26, 2002 Subject 20 Bulletin with which this UL 508 proposal is coordinated includes mandatory marking requirements that exceed the revised requirements of the 2002 NEC Article 404.15(8). As a result of strongly adverse STP 20 and NEMA comments, UL has agreed to revise the Subject 20 proposal in accordance with the NEMA counter-proposal to “Switches that are marked OFF shall completely disconnect all ungrounded conductors in the circuit when in the OFF position. For example, switches that incorporate in-line components, such as a neon indicators that pass current through the load in the OFF position, shall not be marked OFF.“ This is significant not only to outlet-box-mounted Manual Motor Controllers NLRV but also to lighting controls UL 508-Listed as Miscellaneous Apparatus NMTR. If revised as shown below, consider my “NO“ vote changed to “YES“. ActionlDisposition Agree. See revised 16.7 in Appendix B. Agree. See revised 16.7 in Appendix B. Table Continued on Next Page SUBJECT 508 -A6- AUGUST 28,2003 Table Continued Comment Submitter Paragraph I Text Reference ActionlDisposition I Comment or Comment Summary Revise proposed 16.7: A switch intended for mounting in an outlet box and with an identified “off“ function, such as a marked “OFF“ or “O“ switch position, shall be constructed such that when the switch is in the “off“ mode, all ungrounded conductors are completely opened by means of an air gap between the line and load terminals. Swtkhe nnrrn nnn “I I “I “ For examde, switches incorporating in-line components, such as a neon indicator, shall not be marked “OFF“ or “O“. Topic 12: Revisions Based Upon ANSI Canvass Comments Comment Submitter Paragraph I Text I Reference Dieter Reiss Moeller I Topic 12 Revisions Comment or Comment Summary I ActionlDisposition I would like to point out that care should be taken in order to include all the revisions from Topic 12 into the UL 60947-1 and UL 60947-4-1 standards wherever it is necessary to be shown. Agree. The revised UL 508 requirements under this agenda item are either, a) already incorporated into the text of the UL 60947 series, orb) worded in a different way from the UL 60947 series requirement, or c) not included at all in the UL 60947 series at this time. Topic 13: Printed Wiring Board Abnormal Test SUBJECT 508 -A7- AUGUST 28,2003 Comment Submitter Brian Rock Hubbell Incorporated Paragraph I Text Reference 50.1 Comment or Comment Summary I ActionlDisposition The Rationale for Topic 13 indicates that “the test can be performed in lieu of functional spacings“ but the proposed Paragraph 60.1 is worded to mandate BOTH the minimum spacings specified AND performing the test. To me, “in lieu of“ means “as an alternative to“, not “in addition to“. Suggested Revision By Commenter: At each point where spacings on printed wiring boards are as less than specified in 36.12, the printed wiring board is tested as described in 60.2 - 60.6 with adjacent printed circuit paths short-circuited one at a time until the operation of an integral protective device, the opening of a component as described in 60.2, or unti