1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared and published by Underwriters Laboratories Inc.(UL). It is normative for the a
2、pplicable UL Product Certification Program(s); however, it is currently notpart of the UL Standard(s) referenced below.Product Category (CCN): QGRWStandard Number: UL 859Standard Title: Standard for Household Electric Personal Grooming AppliancesEdition Date: June 20, 2012Edition Number: 11Section /
3、 Paragraph Reference: 43.3Subject: Input AveragingDECISION:43.3 The power input to the appliance is to be measured with the appliance at operating temperatureunder full-load conditions, and while connected to a circuit of a voltage in accordance with 44.1.13. Controlswitches or the equivalent, if pr
4、ovided, are to be set to give the maximum power input. For an appliancehaving a preheat cycle of operation as defined in 5.33, the maximum input value measured during thepreheat cycle, with the appliance at room temperature at the beginning of the measurement, is to be usedto determine compliance wi
5、th the requirement specified in 43.1.Exception No. 1: The power input of an appliance that uses a positive temperature coefficient (PTC)heating element shall be measured 1 minute after it has become energized.Exception No. 2: For appliances employing a positive temperature coefficient (PTC) heating
6、element, ifpower input cannot be measured at 1 minute, the power input is determined as the mean value of thepower input occurring during a 30-minute representative period. Compliance of 43.1 is based oncalculated mean wattage.RATIONALE FOR DECISION:PTC heating elements generate a nonlinear input ov
7、er time due to the characteristic temperature versusresistance curves. Therefore it may not possible to measure a stable PTC inputs at 1 minute. Use ofelectronic controls with step functions may cause varying inputs over the 30 minute period requiring anaverage to be measured so that the measurement
8、 is not taken during a low or OFF state of the element.Measurement by input averaging has recently been adopted by IEC 60335-2-23, the IEC Standard forParticular requirements for appliances for skin or hair care, in order to address these considerations withthe intent of measurement of a more repres
9、entative input of the appliance.Copyright 2016 Underwriters Laboratories Inc.UL, in performing its functions in accordance with its objectives, does not guarantee or warrant thecorrectness of Certification Requirement Decisions it may issue or that they will be recognized or adoptedby anyone. Certif
10、ication Requirement Decisions are the opinion of Underwriters Laboratories Inc. inpractically applying the requirements of the standard. They do not represent formal interpretations of thestandard under American National Standards Institute (ANSI) processes. UL shall not be responsible toanyone for
11、the use of or reliance upon Certification Requirement Decisions by anyone. UL shall not incurany obligation or liability for damages, including consequential damages, arising out of or in connectionwith the use or reliance upon Certification Requirement Decisions. The electronic version of theCertif
12、ication Requirement Decision is the current version and previously printed copies may be outdated.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULThis document is published as a service to ULs certification customersSTANDARD NUMBER: UL 859 -2-
