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1、n Underwriters Laboratories Inc. Subjects 45 (745 series, 987) (in reply, refer to Subject 45) Northbrook, Illinois* (847) 272-8800 Melville, NewYork*(516) 271-6200 Santa Clara. California * (408) 985-24C : Research Tnangle Park, North Carolina*(919) 549-1400 Camas. Washington. (360) 817-530 a cenhi
2、ry of public saleiy est 1894 12 Laboratory Drive Research Trikgle Park, NC 27709 February 7,2000 TO: Industry Advisory Conferences of UL for: Portable Electric Tools, and Stationary and Fixed Electric Tcols; Casualty Council of underwriters Laboratories Inc., Consumer Advisory Council of Underwriter
3、s Laboratories Inc., Electrical Council of Underwriters Laboratories Inc., Subscribers to ULs Standards Services for: Portable Electric Tools, Stationary and Fixed Electric Tools, and Bi-National Standard for Portable Electric Tools SUBJECT: Report of the Meeting of the Industry Advisory Conferences
4、 of UL for Portable Electric Tools and Stationary Electric Tools; Request for Comments on Proposed Requirements for the First Edition of the Standard for Portable Electric Tools, UL 745-1 ; Request for Comments on Proposed Requirenieiits for the Sixth Edition of the Standard for Stationary and Fixed
5、 Electric Tools, UL 987; PROPOSED EFFECTIVE DATES SUMMARY OF TOPICS The following topics were discussed at the meeting: 1. Leakage Current and Temperature Test (745-1) 2. Polarization and Switch Endurance (745-1) 3. Glands (745-1) 4. Terminals (745-1) 5. Oxygen Bomb Test (745-1) 6. Polymeric Parts (
6、745-1) 7. Increasing Voltage Limit for Battery-Operated Tools (745-3) 8. Miscellaneous Changes (745-1, 987) A not-for-profit organization dedicated to public safety and committed to quality service COPYRIGHT Underwriters Laboratories Inc. Licensed by Information Handling Services COPYRIGHT Underwrit
7、ers Laboratories Inc. Licensed by Information Handling Services p1 9275795 OA2bO4B 542 Subjects 45 (745 series, 987) -2- February 7,2000 (CONTINUED) 9. 745 Update (745) 11. Table Saw Guarding (987) i 2. Accessories (745) 13. Short Form Test Package (745) 14. Compound Table and Miter Saw (987) 15. Al
8、lied Standards (45, 745, 987) 10. ANSI 87.1-2000 (745) COMMENTS DUE: APRIL 3,2000 A joint meeting of the Industry Advisory Conferences of UL for Portable Electric Tools and Stationary Electric Tools was held on December 7 eliminating any misinterpretation. Both UL and CSA staffs have been accepting
9、UL Listed and/or CSA Certified switches suitable for the application. However, in reviewing the test procedures, UL found that these switches which have been accepted have only been tested for 6,000 cycles of operation. UL proposes to add an explanatory note that references the standards in Appendix
10、 E should be added to sub-clause 22.2. IMPACT No review or retest of existing products will be necessary since all currently Listed products comply with the proposed requirements. COPYRIGHT Underwriters Laboratories Inc. Licensed by Information Handling Services COPYRIGHT Underwriters Laboratories I
11、nc. Licensed by Information Handling Services - - W 927579C 082b050 LTU Subjects 45 (745 series, 987) -4- February 7,2000 3. GLANDS (745-1) RATIONALE A requirement within sub-clause 23.5 states “Glands shall not be used as cord anchorages for power supply cords”. An explanatory note, following this
12、requirement, defines the term “glands”. The term “glands” refers to a cord passing through compression packing of the type generally used to prevent the entry of moisture or dust. As cord flexing is not a requirement for magnetic drills, diamond drills, floor supported drain cleaners, and similar to
13、ols that are floor supported during normal operation, the compression fitting type strain relief shall be judged as to its adequacy to prevent a strain from being transmitted to internal wiring connections. UL proposes to add an explanatory note to sub-clause 23.5 to correct the current text. UL pro
14、poses that this requirement become effective upon the date of publication. IMPACT No review or retest of existing products will be necessary since all currently Listed products comply with the proposed requirements. 4. TERMINALS (745-1) RATIONALE Clause 24.1 of UUCSA 745-1 states that “Tools shall b
15、e provided with terminals in which connection is made by means of screws, nuts or equally effective devices”. As vibration is expected within motor operated tools, wire nut type devices are not acceptable as terminating devices for external conductors. Wire nuts that are machine applied, or tightly
16、covered with at least 2 wraps of electrical grade tape secured to the leads, are considered acceptable. UL proposes an explanatory note to sub-clause 24.1 that agrees with current North American manufacturing practices and agrees with current requirements of UL 45 and CSA 22.2 No. 71.1. UL proposes
17、that this requirement become effective upon the date of publication. IMPACT No review or retest of existing products will be necessary since all currently Listed products comply with the proposed requirements COPYRIGHT Underwriters Laboratories Inc. Licensed by Information Handling Services COPYRIGH
18、T Underwriters Laboratories Inc. Licensed by Information Handling Services Subjects 45 (745 series, 987) -5- February 7,2000 5. OXYGEN BOMB TEST (745-1) RATIONALE The oxygen pressure heat aging method has long been used by test labs to accelerate the aging of rubber materials. More than 20 years ago
19、, the rubber industry stopped using oxygen bombs and replaced the bomb test with an air oven aging test. A 70-hour test in an air oven at a temperature of IOOoC 242 or 1OoC c 2 4 above operating temperature, whichever is higher, is the rubber industry test for materials rated at 6 O . C and under. I
20、ndustry supports the replacement of the oxygen bomb test with the air oven aging test because of the dangers involved with oxygen under pressure and because it is more convenient. Additionally, the oxygen bombs are no longer being manufactured. Therefore, UL proposes to replace the 96 hour oxygen bo
21、mb test with the 70-hour air oven aging test at a temperature of I O O C 2oC or 10.C i 2oC above operating temperature, whichever is higher, as shown in the proposal below. UL proposes that this requirement become effective upon the date of publication. IMPACT As the air oven aging test is considere
22、d equivalent to the oxygen bomb test, no review, modifications, or retest will be required if this proposal is adopted. Manufacturers would not be required to conduct accelerated aging tests according to the air oven aging test on products that have already been tested with the oxygen bomb. 6. POLYM
23、ERIC PARTS (745-1) DISCUSSION The IAC discussed motor insulation investigation when a tool is evaluated to UUCSA 745-1. Manufacturers state that motor insulation should not be considered during tool investigation. When a motor employs components that are not Recognized or accepted generically, then
24、UL wants to know material makeup of the component. UL also wants to know long-term aging of the motor insulation when the components are not known. Manufacturers state that the overload burnout test is used to test the compliance of the motor and its components. Manufacturers noted that the motor as
25、 a system should be investigated, not components of the motor. UL will contact CTL (Committee of Testing Laboratories) to confirm which critical components are needed for description in CB reports. UL will also verify if the rest of the world is measuring motor insulation. UL will continue to resear
26、ch information needed to clarify the requirements. UL has been allowing testing of motor systems to sub-clause 11.6, where motor temperature excursions that exceed Class E limits so long as the motor insulation system i s only referred to and identified as a specified temperature. This allowance was
27、 based upon the fact that portable tools are attended. Should the manufacturer elect to employ a UL Recognized Component Insulation System (OBJY2), the system would be made up of components used in accordance with their Recognized ratings and tested to the Full Thermal Aging Test. The components wou
28、ld also undergo a Sealed Tube Test that would evaluate the combination of these materials. This test helps determine the chemical reaction of the complex materials making up the insulation system and if the desired temperature Class would be affected by the combination of materials. Again UL omitted
29、 this particular test from the requirements in UL 745 based upon the attended use of the portable tool. COPYRIGHT Underwriters Laboratories Inc. Licensed by Information Handling Services COPYRIGHT Underwriters Laboratories Inc. Licensed by Information Handling Services - 92751115 082b052 T73 W -6- S
30、ubjects 45 (745 series, 987) February 7,2000 Further, there is no direct correlation between the testing described in UL 745 and the long-term testing described in UL 746C. If UL allows insulating materials to be used that are rated less than the temperatures found in the end product evaluation, UL
31、is left without any true long-term evaluation of the individual materials making up the motor insulation. Therefore, UL must require that the individual motor insulation system materials be used in accordance with their specified ratings as stated in the notes of the table following sub-clause 11.5.
32、 In summary, UL has substituted the test of 11.6 for the compatibility test. This does not change, or substitute, the basic requirements applicable to the insulation materials used. The test of 1 1.6 is not a suitable indicator of how materials will perform over the life of the tool. It is an indica
33、tor of the suitability of the combination of materials used. Without, this understanding, UL would be in the position of accepting materials for use at temperatures above their rating based only on the 1 1.6 test. This is not in accordance with the words or intent of UL 45, or UL 745. This matter is
34、 being reviewed by the Binational Working Group and a resolution will be published in the near future. RATIONALE Requirements for the evaluation of polymeric parts employed in portable tools are not specified in sub- clause 28.2. These requirements should apply to both polymeric enclosures and polym
35、eric parts retaining live parts of the tool in position. Therefore, UL proposes to add text to the first and third paragraphs of sub-clause 28.2 to indicate the requirements specified in this clause refer to both polymeric enclosures and polymeric insulating parts retaining live parts in position. U
36、L proposes that this requirement become effective upon the date of publication. IMPACT No review or retest of existing products will be necessary since all currently Listed products comply with the proposed requirements. COPYRIGHT Underwriters Laboratories Inc. Licensed by Information Handling Servi
37、ces COPYRIGHT Underwriters Laboratories Inc. Licensed by Information Handling Services - I7275715 082b053 0 T Subjects 45 (745 series, 987) -7- February 7,2000 7. INCREASING VOLTAGE LIMIT FOR BATTERY-OPERATED TOOLS (745-3) IAC AGENDA ITEMS 7,8,9, a IO DISCUSSION Original IAC agenda items 7, 8 (Volta
38、ge Limits for Battery-Operated Tools), 9 (Thermal Cut-Outs and Overload Releases), and 10 (Switches) were briefly discussed. The proposals for these items were not accepted during the meeting, and it was decided that the UUCSA Working Group should visit each of these items during the next Bi-Nationa
39、l meeting. In a bulletin dated July 30, 1998, UL announced that the voltage between accessible conductive parts on a low voltage battery-pack may exceed 30 volts DC, but not exceed 42.4 volts DC, when all acceptable conditions are met. If the battery voltage exceeds 42.4 V DC, or the openings do not
40、 meet specified probe requirements, then the tool will be evaluated as a Class I or Class II tool as applicable. Based on the IACs input, UL does not plan to propose to increase the voltage limit to 42.4 V DC for battery-operated tools at this time. The IEC standard for battery-operated tools requir
41、es a voltage limit of 75 V DC. It was noted that IEC 479-1 (1994 edition), which describes impedance protection of the human body, considers a DC voltage being equal to 2 to 3 times an AC voltage. It was noted that higher voltages might cause a startle reaction to the user. Industry was opposed to t
42、he addition of any new probes. Although more restrictive, probes in the present standard were recommended by industry. UL stated that more research would be conducted. 8. MISCELLANEOUS CHANGES (745-1,987) RATIONALE UL proposes numerous updates and clarifications to UUCSA 745-1 and UL 987, which shou
43、ld have no technical impact on the requirements of the standards. UL proposes new sub-clause 8.3.3 in UUCSA 745-1. This new sub-clause is needed to clarify insulating requirements on auxiliary grasping surfaces. UL proposes that these requirements become effective upon the date of publication. IMPAC
44、T Because these requirements are non-technical updates and clarifications, no review or retest of currently Listed products will be necessary. 9. 745 UPDATE (745) DISCUSSION Jim Montgomery, Chariman of the Bi-National Working Group, updated the IAC on current proposals to the IEC. A committee draft,
45、 CD, proposal for the 2”d edition of IEC 60745-1 will be discussed at the next IEC meeting scheduled for May 2000 in Frankfurt, Germany. If the U.S. proposal is accepted at the meeting, then the proposal will progress to a voting document (CDV). Other Part 2s will follow the Part 1 when it is accept
46、ed as a voting document. that dont fit the UUCSA 745 series. The U.S. delegates are introducing new Part 2s to the IEC standard carried over from UL 45 (drain cleaners, strapping tools, and bandsaws). The IAC briefly discussed the possibility of adding hedge trimmers and electric chain saws to the U
47、UCSA 745 series, as they are included in the IEC 60745 series. Manufacturers expressed a desire to keep UL 45 for tools COPYRIGHT Underwriters Laboratories Inc. Licensed by Information Handling Services COPYRIGHT Underwriters Laboratories Inc. Licensed by Information Handling Services I 1 2 7 5 7 9
48、5 OB2b059 BYb Subjects 45 (745 series, 987) -8- February 7,2000 IO. ANSI 87.1-2000 (745) BACKGROUND In a bulletin dated April 25, 1996, UL announced that the test program in effect for UL 45 would be used to evaluate grinder guards investigated to UL 745-1, UL 745-3, UL 745-2-3, and UL 745-4-3. When
49、 the UUCSA 745 series was published in 1995, Appendix E of UL 745-lrequired that a grinder guard meet the requirements in ANSI 67.1, the Standard for the Use, Care, and Protection of Abrasive Wheels. UL and CSA agreed that the test parameters in ANSI 67.1 were not fully defined. The Grinding Wheel Institute, sponsors of ANSI 87.1, were made aware of the issue and indicated a concern to revise the standard. Recently, a new edition of ANSI 67.1 was prepared for publication. After a review of the revised standard, UL is concerned that several issues still