1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared by UL LLC. It is normative for the applicable ULProduct Certification Program(
2、s); however, it is currently not part of the UL Standard(s) referencedbelow.Product Category (CCN): DMKKStandard Number: UL 1776Standard Title: Standard for High Pressure Cleaning MachinesEdition Date: June 7, 2002Edition Number: 3Section / Paragraph Reference: 1.2A, Appendix BSubject: Rechargeable
3、Battery-Powered High Pressure Cleaning MachineRequirementsDECISION:1 Scope1.2A These requirements also cover portable rechargeable battery-powered high pressure cleaningmachines for indoor or outdoor use with rechargeable non-user and user-replaceable batteries; seeAppendix B.The following new Appen
4、dix B is all new text. The text is not underlined for ease of reading.APPENDIX B: Rechargeable Battery-Powered Machines (Normative)B1 This Appendix covers machines that are powered by rechargeable batteries either solely or as analternative or in conjunction with other sources.B2 Rechargeable batter
5、y-powered machines that are covered under this Appendix shall comply with therequirements of UL 2595 with the conditions and specifications as required by Annex D of UL 2595 asindicated in Clauses B3 B12 below.B3 In reference to Indent A of Annex D of UL 2595, except as indicated elsewhere in UL 259
6、5, thefollowing requirements in this end-product standard do not apply or are amended as indicated below:a) The Clauses specified in Table B2 below do not apply.b) The Clauses referenced in (a) above apply to machines that are also powered from mains orother non-isolated sources to the extent that t
7、he requirement applies to address the risk ofelectric shock in the area of the machine containing such an electrical source.c) The portions of UL 1776 that require the outcome of the testing to comply with dielectricvoltage withstand and leakage current test, and the wetting of any electrical compon
8、ents, shallinstead consider increased risk of injury to persons, fire, or shock for those areas where thevoltages are in excess of the hazardous voltage; see Section 8 of UL 2595. In the application ofSection 8 of UL 2595, a part that is wetted during the testing of Clause 84 is considered anaccessi
9、ble part.d) The following warning marking is required:Disconnect Battery Pack Before Cleaning or Servicing”, or the equivalent.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULException: This warning is not applicable for batteries that cannot
10、be disconnected from theappliance in normal use.e) For 112.1.2, the electrical rating in volts may be applied. Also see Section 6.2 of UL 2595.f) In the application of the requirements in 113.2.1, the marking only applies to productsoperating at hazardous voltages and shall be marked to indicate tha
11、t such servicing or cleaningis to be done with the battery removed or disconnected, or the equivalent.B4 With respect to Indent B of Annex D of UL 2595, users are considered to be wet during the use ofthese products.B5 With respect to Indent C of Annex D of UL 2595, LT specification is required for
12、batteries forappliances intended and marked to be Stored Indoors, and ELT 35C specification for appliancesintended for Outdoor Use.B6 With respect to Indent D of Annex D of UL 2595, during the Normal Temperature test, appliances shallbe operated with the attachment installed, and without the attachm
13、ent, to determine which mode yieldshigher enclosure temperatures. Appliances capable of using several different attachments shall be fittedwith the attachment that yields higher enclosure temperatures with the limited energy available in abattery.B7 With respect to Indent E of Annex D of UL 2595, th
14、e temperature limits listed in Table 9.1 of UL 2595shall be considered suitable.B8 With respect to Indent F of Annex D of UL 2595, during the abnormal tests, the appliance shall beoperated at no-load in accordance to Clause 11.1.3 of Appendix D of UL 2595.B9 With respect to Indent G of Annex D of UL
15、 2595, additional safety-critical functions (SCFs) areidentified in Table B3 below.B10 With respect to Indent H of Annex D of UL 2595, the impact surface is to be conducted on concrete.B11 With respect to Indent I, the products specified in Table B.1 below shall have the switchingarrangement as spec
16、ified.STANDARD NUMBER: UL 1776 -2-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable B1Machine types - Switching arrangement requirementsMachine type Requires compliance with switching arrangementspecified in 18.5 of UL 2595Type 2 Cleaning
17、Machine YesType 3 Cleaning Machine YesA floor- or ground-supported product in accordance with 56.12 YesOther machine employing exposed cutting device or highpressure nozzle whose inadvertent operation may result in arisk of serious injury or death.YesOther machine:a) Without exposed cutting device o
18、r high pressurenozzle, orb) Whose inadvertent operation does not result in arisk of serious injury or deathNoB12 With respect to Indent J of Annex D of UL 2595, battery-operated cleaning machines that can alsobe operated or charged by mains or a non-isolated source as described in UL 2595, shall als
19、o meet therequirements of this end-product standard that apply to the risk of electric shock. For these types ofcleaning machines, the exempted requirements specified in Clause B3 of this Appendix may beapplicable.Table B2 - Requirements not applicable for battery-powered cleaning machines(See Claus
20、e B3(a)Title ClauseScope 1.4Glossary 2.3Assembly 7.6Materials, Fluid Confining Parts 8.2.2, 8.2.3Nonmetallic materials 8.3.1 (covered by UL 2595, resistance to heat and fire)Frame and Enclosure 11.3, 11.4, 11.5, 11.6, 11.6.1, 11.8 11.17Accessibility of Uninsulated Live Parts and Film-Coated Wire 15S
21、upply Connections 16Insulating Material 18Internal Wiring 19.1 19.2, 19.5Capacitors 20Grounding 21Heating Elements 22Water Heaters 23Lampholders 24Motors 25Overload or Thermal Protective Devices 26Receptacles 27Switches and Controls 28Automatic Temperature Controls 29Spacings 30Mechanical Systems an
22、d Devices Engine Driven Products 31 32Mechanical Systems and Devices Fuel Fired Products 33 46STANDARD NUMBER: UL 1776 -3-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable B2 - Requirements not applicable for battery-powered cleaning machi
23、nes ContinuedMaterials 50Surface Temperature Test 61Electrical Systems 62.2Fuel-Fired Products 62.3Instrumentation 63Installation 64Gas-Fired Products 65.2Oil-Fired Products 65.3Normal Temperature Test 67Fuel-Fired Products 68.3Tests on Gaskets, Seals, and Parts 70 (Note: 70.6 is applicable)Tests on
24、 Nonmetallic Enclosures and Guards 71Performance Electrical Systems 77 83, 88 91Performance Fuel-Fired Systems 92 106Performance Products with Internal Combustion Engines 107Dielectric voltage-Withstand Test 108Ground Continuity Test 109Fuel System Leakage Test 110Marking - General 112.1.13 - 112.1.
25、15, 112.1.18 - 112.1.23Marking Permanently Connected Products 112.2Marking Component Marking 112.3Cord-Connected Products 112.4Servicing 113.2.2, 113.2.3Gas and Oil-fired Products 113.3Engine Driven Products 113.4Electrically Operated Products 113.5Important Safety Instructions 115.2, Items 9 and 10
26、; 115.2 b), 115.3Installation Instructions 116User-Maintenance Instructions 117Table B3Additional safety-critical functions (SCFs) for automatic battery-powered machines(See Clause B9)Type and Purpose of SCF MinimumPerformance Level(PL)Prevents accidental ON where the user may be exposed tothe risk
27、of injury due to moving or rotating parts or highpressure water.bProvides OFF functionality for appliances where the usermay be exposed to the risk of injury due to moving orrotating parts or high pressure water.bPrevent exceeding thermal limits as specified in Section 9of UL 2595bInterlocks require
28、d by UL 1776. bPrevent self-resetting as required in 56.7 bSTANDARD NUMBER: UL 1776 -4-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULRATIONALE FOR DECISION:UL was approached to investigate battery-powered high pressure cleaning machines. Sin
29、ce UL 1776does not have battery-powered requirements, new requirements needed to be developed. This UL 1776Certification Requirement Decision (CRD) incorporates the use of UL 2595 in the investigation ofbattery-powered high pressure cleaning machines. UL 2595 is the Standard for General Requirements
30、 forBattery-Powered Appliances. It is a horizontal standard that is structured to be used in conjunction withend-product standards.Here is background on the use of UL 2595:With respect to Safety Critical Functions (SCF) and Performance Levels (PL), ISO 13849-1 provides asimplified method for establi
31、shing the associated reliability of a safety critical control function inconsideration of the risk of injury associated with its failure. The control function is assigned aPerformance Level (PL) which then may be fulfilled with a control system that satisfies both structuralrequirements and minimum
32、calculated failure rates expressed in MTTFd (Mean Time To DangerousFailure).Risk AssessmentThe method of risk assessment used in ISO 13849-1 follows the same general approach as in ISO 12100,where primary consideration is given to the severity of the hazards and the frequency of encounteringthese ha
33、zards. The risk associated with that hazard is then subsequently reduced by consideration of theprobability, P, for avoiding the hazard. In ISO 12100, this analysis is carried out using the original,unmitigated hazard followed by all the risk mitigation techniques used to determine the resulting res
34、idualrisk of the appliance with respect to the hazard (and phase of use) under consideration.When assessing a safety-critical function (SCF), this process is not so clear: In this case, the safety-criticalfunction may be only one of many elements in the appliance design intended to reduce the risk a
35、ssociatedwith a hazard. The goal then is to establish the change in residual risk associated with the failure of theSCF and to determine the remaining residual risk and whether it is still acceptable. This method, takenfrom ISO 12100, is not well suited to be used in this manner and additional consi
36、derations must be takeninto account to yield meaningful results. Part of the issue is due to the fact that a binary tree is used togenerate one of a discrete number of PLs and this sometimes fails to recognize small differences in risk.While this makes this method easy to use, it introduces some pro
37、blems in analysis.Residual Risk AnalysisIn recognition of the hazards associated with some appliances in general, UL appliance standards employa number of risk mitigation techniques, built into the requirements of the standard, to reduce the risk to anacceptable level. These techniques are often int
38、ended to work together, as a system, to achieve therequired risk reduction. An electronic control providing an SCF is often only one part of this system andits failure, therefore, does not leave the appliance without other risk mitigation elements. To assess theeffect of the loss of an electronic co
39、ntrol function two things are considered.First, the control function must fulfill a required safety element of the standard. The standard is presumedto have left the appliance with an acceptable level of residual risk. Controls whose failure does notincrease the risk beyond this already accepted lev
40、el are not considered to be a SCF within this standard.In addition, there must be a substantial impact on residual risk due to the failure of the SCF. To determinethis, performance levels can be assessed both with and without the presence of the SCF, but with all otherrisk mitigation in place. It is
41、 possible that this will yield the same PL with or without the SCF.STANDARD NUMBER: UL 1776 -5-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULIf it is recognized that the SCF fulfills a required safety function, but the PL remains the same wi
42、th orwithout its presence, then in these cases, a minimum level of PL=aisused.While the method above yields meaningful results under conditions of normal operation, there are SCFsthat are relied on to protect the user under conditions of reasonably foreseeable misuse or other caseswhere the risk occ
43、urs only under a specific set of unlikely preconditions. An example of this is the casein systems to protect against restart after power interruption, since restart requires the appliance to beswitched on, plugged in and power interrupted and restored while the user is nearby.In cases such as these,
44、 the unlikelihood associated with the event should dominate the analysis. Themethod used in ISO 13849-1, however, gives priority to the severity of the hazard (S, F, P) such that, forhigh severity cases, it would not be possible to assign a severity less than PL = c, because the frequency(F) is anal
45、yzed second. In cases such as these the order of analysis should be reversed (F, S, P) allowingthe frequency of exposure to have a higher influence over the outcome.Performance levels have been assigned in this standard reflecting common cases. There is recognitionthat there may be SCFs in the futur
46、e not yet contemplated by this standard, and ISO 13849-1 along withthis Appendix may be used for guidance in setting the appropriate performance level.Performance Levels (PL)ISO 13849-1 provides methods for achieving the various performance levels. These solutions generallyrequire certain structures
47、 such as dual channel, single channel and single channel with diagnostics. Singleand dual channel refer to the functional redundancy of the control. Since protective control andsafety-critical function circuit evaluations have dual channel designs evaluated before performance levelsof other structur
48、es are even considered, most of the interest in ISO 13849-1 is focused on single channeldesigns. While ISO 13849-1 permits diagnostic monitoring of lower reliability single channel systems asan alternative to unmonitored high reliability single channel, there is a concern that these diagnostics areu
49、nlikely to be noticed by an operator of the appliance under use conditions. As a result, the standardgenerally prohibits these solutions as an alternative to higher reliability designs.As a result, the single channel designs afforded by this method require increasingly higher MTTFd as thePL increases due to increasing risk.It may be possible that a case could exist where a diagnostic reflecting the unavailability of a SCF ispresent and recognizable well in advance of the operator being exposed to the increased risk. It could beappropriate in this case to
