ANSI UL 466-1999 UL Standard for Safety Electric Scales (Eighth Edition Reprint with revisions through and including June 13 2013).pdf

1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 466 Electric ScalesUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION O

2、R DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Electric Scales, UL 466 Eighth Edition, Dated March 25, 1999 Summary of Topics This revision of ANSI/UL 466 is being issued to reaffirm approval as an American National Standard. No changes in requirements are involved. Text that h

3、as been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. The revisions are substantially in accordance with Proposal(s) on this subject dated March 8, 2013. All rights reserved. No part of this publication may be reproduced, stored i

4、n a retrieval system, or transmitted in any form by any means, electronic, mechanical photocopying, recording, or otherwise without prior permission of UL. UL provides this Standard as is without warranty of any kind, either expressed or implied, including but not limited to, the implied warranties

5、of merchantability or tness for any purpose. In no event will UL be liable for any special, incidental, consequential, indirect or similar damages, including loss of prots, lost savings, loss of data, or any other damages arising out of the use of or the inability to use this Standard, even if UL or

6、 an authorized UL representative has been advised of the possibility of such damage. In no event shall ULs liability for any damage ever exceed the price paid for this Standard, regardless of the form of the claim. Users of the electronic versions of ULs Standards for Safety agree to defend, indemni

7、fy, and hold UL harmless from and against any loss, expense, liability, damage, claim, or judgment (including reasonable attorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronic Standard on the purchasers computer system. The requirements in this Stan

8、dard are now in effect, except for those paragraphs, sections, tables, gures, and/or other elements of the Standard having future effective dates as indicated in the note following the affected item. The prior text for requirements that have been revised and that have a future effective date are loc

9、ated after the Standard, and are preceded by a SUPERSEDED REQUIREMENTS notice. JUNE 13, 2013 UL 466 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JUNE 13, 2013 UL 466 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FU

10、RTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL MARCH 25, 1999 (Title Page Reprinted: June 13, 2013) 1 UL 466 Standard for Electric Scales The rst through fth editions were titled Electrically Illuminated Scales. First Edition November, 1953 Second Edition November, 1966 Third Edition

11、April, 1971 Fourth Edition November, 1976 Fifth Edition June, 1982 Sixth Edition May, 1983 Seventh Edition January, 1994 Eighth Edition March 25, 1999 This ANSI/UL Standard for Safety consists of the Eighth Edition including revisions through June 13, 2013. The most recent designation of ANSI/UL 466

12、 as a Reaffirmed American National Standard (ANS) occurred on June 13, 2013. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, Title Page, or effective date information. Comments or proposals for revisions on any part of the Standard may be submitted to UL at any time.

13、 Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) at http:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way. All of ULs Standards and all copyrights,

14、 ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2013 UNDERWRITERS LABORATORIES INC. ANSI/UL 466-2004 (R2013)UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL APRIL 28, 2004 ELECTR

15、IC SCALES - UL 466 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .5 2 General 5 2.1 Components .5 2.2 Units of measurement .6 2.3 Undated references .6 CONSTRUCTION 3 Enclosure 6 4 Mechan

16、ical Assembly 6A 5 Protection Against Corrosion 6A 6 Supply Connections 6A 7 Grounding 6B 8 Internal Wiring 7 9 Switches .8 10 Ballasts .9 11 Spacings 9 12 Double-Insulated Scales 9 PERFORMANCE 13 Temperature Test 9 14 Dielectric Voltage-Withstand Test .10 15 Endurance Test 11 MANUFACTURING AND PROD

17、UCTION TESTS 16 Production-Line Dielectric Voltage-Withstand Test 11 17 Production-Line Grounding-Continuity Test .12 RATINGS 18 Details .13 MARKINGS 19 Details .13 APPENDIX A Standards for ComponentsA1 APRIL 28, 2004 ELECTRIC SCALES - UL 466 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRO

18、DUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL This page intentionally left blank. APRIL 28, 2004 ELECTRIC SCALES - UL 466 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover portable scales

19、, including counter, jewelry, grain, oor and other electronic scale designations. These scales are ordinarily of the computing type, that are rated 250 volts or less. These scales consist of an attachment plug, a length of exible cord, a switch, one or more lamps, lampholders, ballasts if electric-d

20、ischarge lamps are used, and associated internal wiring. They are intended to be used in accordance with the National Electrical Code, NFPA 70. 1.1 revised April 28, 2004 1.2 These requirements do not cover scales involving electronic computing features or electrical features such as motor-operated

21、components, relays, and provision for permanent connection to the power supply. Such scales are evaluated under the applicable requirements in the Standard for Information Technology Equipment Safety Part 1: General Requirements, UL 60950-1. 1.2 revised March 18, 2010 1.3 Deleted April 28, 2004. 1.4

22、 In this standard, portable equipment is dened as equipment that can be easily moved from one place to another in normal use. 1.4 added April 28, 2004 2 General 2.1 Components 2.1.1 Except as indicated in 2.1.2, a component of a product covered by this standard shall comply with the requirements for

23、 that component. See Appendix A for a list of standards covering components generally used in the products covered by this standard. 2.1.2 A component is not required to comply with a specic requirement that: a) Involves a feature or characteristic not required in the application of the component in

24、 the product covered by this standard, or b) Is superseded by a requirement in this standard. 2.1.3 A component shall be used in accordance with its rating established for the intended conditions of use. 2.1.4 Specic components are incomplete in construction features or restricted in performance cap

25、abilities. Such components are intended for use only under limited conditions, such as certain temperatures not exceeding specied limits, and shall be used only under those specic conditions. MARCH 18, 2010 ELECTRIC SCALES - UL 466 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR

26、DISTRIBUTION WITHOUT PERMISSION FROM UL 2.2 Units of measurement 2.2.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information. 2.2.2 Unless otherwise indicated, all voltage and current values mentioned in this standard are root-mean-sq

27、uare (rms). 2.3 Undated references 2.3.1 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard. CONSTRUCTION 3 Enclosure 3.1 A scale shall be provided with an enclosure that has been

28、 investigated and determined to be acceptable for the housing of all electrical parts other than the power-supply cord. 3.2 A cast- or sheet-metal enclosure shall not be thinner than specied in Table 3.1. Exception: A sheet metal enclosure may be thinner if its strength and rigidity is not less than

29、 that of sheet steel 0.66 mm (0.026 inch) thick. 3.2 revised April 28, 2004 Table 3.1 Minimum thicknesses of enclosure metal Table 3.1 revised April 28, 2004 At small, at unreinforced surfaces; at surfaces that are reinforced by curving, ribbing, and the like; and at surfaces of a shape or size to p

30、rovide necessary mechanical strength, At relatively large, unreinforced, at surfaces, Metal mm inch mm inch Die-cast metal 1.2 3/64 2.0 5/64 Cast malleable iron 1.6 1/16 2.4 3/32 Other cast metal 2.4 3/32 3.2 1/8 Uncoated sheet steel 0.66 0.026 0.66 0.026 3.3 An enclosure of material other than meta

31、l shall be investigated to determine its acceptability for the purpose. 3.4 An environmental enclosure shall comply with the applicable requirements specied in the enclosure types table of the Standard for Enclosures for Electrical Equipment, Non-Environmental Considerations, UL 50. 3.4 revised Marc

32、h 18, 2010 MARCH 18, 2010 ELECTRIC SCALES - UL 466 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 4 Mechanical Assembly 4.1 A scale shall have the strength and rigidity necessary to resist the abuses to which it may be subjected, without r

33、esulting in a risk of re, electric shock, or injury to persons due to total or partial collapse with resulting reduction of spacings, loosening or displacement of parts, or other serious defects. 4.2 Uninsulated live parts shall be mechanically secured and prevented from turning by means other than

34、friction between surfaces. 4.3 A component, such as a switch or a lampholder, shall be securely mounted and shall be prevented from turning by means other than friction between surfaces. 4.4 A small stem-mounted switch may be prevented from rotating by a tightly applied lock washer. 4.5 The applicat

35、ion and means of mounting of a lampholder of other than the screw shell type shall be subjected to an investigation to determine its acceptability. 5 Protection Against Corrosion 5.1 Iron and steel parts shall be protected against corrosion by enameling, galvanizing, plating, or an equivalent means

36、if corrosion of such parts is likely to result in a risk of re, electric shock, or injury to persons. Exception No. 1: Cast-iron parts are not required to be protected against corrosion. Exception No. 2: In certain applications in which the oxidation of steel is not likely to be accelerated due to t

37、he exposure of metal to air and moisture thickness of metal and temperature also being factors surfaces of sheet steel within an enclosure are not required to be protected against corrosion. 6 Supply Connections 6.1 A scale shall be provided with Type S, SJ, SJE, SJEO, SJO, SJOO, SJT, SJTO, SJTOO, S

38、E, SEO, SO, SOO, ST, STO, or STOO exible cord and an attachment plug for connection to the supply circuit. Exception: A laboratory balance, postal scale, or parcel-post scale intended for countertop use may be provided with Type SV, SVE, SVO, SVOO, SVT, SVTO, SVTOO, SP-2, or SPT-2 exible cord. 6.2 S

39、train relief shall be provided to reduce the risk of mechanical stress on the exible cord from being transmitted to connections inside a scale or to the attachment plug. 6.3 If a knot in a exible cord serves as strain relief, the surfaces that the knot may contact shall be free from burrs, ns, sharp

40、 edges, and projections that may damage the cord. 6.4 The edges of a hole in a wall, a barrier, or an enclosure through which a cord passes shall be smooth and free from burrs, ns, and sharp edges. APRIL 28, 2004 ELECTRIC SCALES - UL 466 6AUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCT

41、ION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 6.5 If an insulating bushing provided where the power-supply cord enters the enclosure is of material other than ceramic, phenolic, cold-molded composition, or ber, the hole in the metal in which the bushing is mounted shall be smooth and free from burr

42、s, ns, and sharp edges. 7 Grounding 7.1 A dead metal part that may become energized and that is exposed or accessible during intended use or operator servicing shall be conductively connected to the equipment-grounding conductor of the power-supply cord. Exception: For a double-insulated scale, the

43、supply cord shall not include an equipment-grounding conductor. See Double-Insulated Scales, Section 12. 7.2 A conductive part that is accessible to service personnel shall be connected to the equipment-grounding conductor of the power-supply cord or provided with a marking in accordance with 19.5 i

44、f the part is: a) Usually expected to be at ground potential and b) Likely to become energized from a circuit at an AC potential greater than 30 volts rms (42.4 volts peak) or a DC potential greater than 60 volts with reference to ground. 7.3 If two or more units of a scale system are electrically c

45、onnected to one another and one of them is grounded: a) Those parts specied in 7.1 and 7.2 shall be grounded on all of the units and b) Each unit that has a separate supply cord shall have a grounding-type cord. All of the units shall be bonded together, such as by an equipment-grounding conductor i

46、ncluded in an interconnecting cable. 7.4 The equipment-grounding conductor of a power-supply cord shall be: a) Provided with insulation having an outer surface that is green with or without one or more yellow stripes and b) Connected to the xed grounding blade or equivalent contacting member of an a

47、ttachment plug. 7.5 The connection between dead metal parts required to be grounded and the equipment-grounding conductor: a) Shall be made by a screw or other means not likely to be removed during ordinary servicing not involving the power supply cord and b) Shall not be made by solder alone. APRIL

48、 28, 2004 ELECTRIC SCALES - UL 466 6BUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 7.6 A convenience receptacle provided on a grounded scale shall be of the grounding type and shall be grounded. 7.7 If a means for grounding that is not req

49、uired is provided on a scale, it shall comply with the requirements in 7.1 7.6. 7.8 The provision of a multiple-conductor exible cord having one conductor connected to the enclosure or frame of the scale may be used as means for grounding. 8 Internal Wiring 8.1 Internal wiring of a scale shall be investigated and determined to be acceptable for the application when considered with regard to the temperature, voltage, and other conditions of service to which the wiring may be subjected. 8