UL 778 CRD-2018 UL Standard for Safety Motor-Operated Water Pumps - Section Paragraph Reference 41 1 41 2 55 Subject Add DC Test Potential of Dielectric Voltage Withstand Test (Ed.pdf

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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): REUZ, AWEG, IQRWStandard Number: UL 778Standard Title: Standard for Motor-Operated Water PumpsEdition Date: July 7, 2016Edition Number: 6Section / Paragraph Reference: 41.1, 41.2, 55Subject: Add DC Te

3、st Potential of Dielectric Voltage Withstand Test.DECISION:PERFORMANCE41 Dielectric Voltage-Withstand Test41.1 General41.1.1 A pump shall withstand for 1 minute without electrical breakdown the application of a DC potentialor an AC 60-hertz, essentially sinusoidal potential at a frequency within the

4、 range of 40 to 70 Hz:a) Between live parts and grounded dead metal andb) Between the terminals of a capacitor used for radio interference elimination or arcsuppression.The test potential shall be as follows shown in Table 41.1:1) One thousand volts for a nonsubmersible pump rated no more than 250 v

5、olts, and no more than 1/2horsepower (373 watt output).2) One thousand volts plus twice the rated voltage for a nonsubmersible pump rated more than 250 volts,or more than 1/2 horsepower.3) One thousand volts plus twice the rated voltage for a submersible pump.UL COPYRIGHTED MATERIAL NOT AUTHORIZED F

6、OR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable 41.1Dielectric voltage withstand voltagesMachine voltage rating, V Test potential V AC Test potential V DCA nonsubmersible pump rated no morethan 250 volts, and no more than 1/2horsepower (373 watt output)1000 1400A nonsubmersibl

7、e pump rated more than250 volts, or more than 1/2 horsepower1000 + 2Va1400 + 2.8VaA submersible pump 1000 + 2Va1400 + 2.8VaaMaximum marked voltage.41.2 Secondary circuits41.2.1 Secondary circuits shall withstand for 60 seconds without electrical breakdown the application of atest potential in accord

8、ance with 41.2.2:a) Between primary and secondary circuits,b) Between secondary circuits and grounded metal with all frame-connected components inplace, andc) Between secondary circuits supplied from separate transformer windings with commonconnections disconnected and frame connections in place.The

9、 pump is to be at its maximum normal operating temperature during the test. A DC potential or an AC60-hertz essentially sinusoidal voltage potential at a frequency within the range of 40 to 70 Hz is to beused for testing alternating-current circuits.Table 41.2Dielectric voltage withstand voltages fo

10、r Secondary circuitsMachine voltage rating, V Test potential V AC Test potential V DCA secondary circuit operates at 51 - 250volts500 700A nonsubmersible pump rated more than250 volts, or more than 1/2 horsepower1000 1400A submersible pump 1000 + 2Va1400 + 2.8VaaMaximum operating voltage.MANUFACTURI

11、NG AND PRODUCTION-LINE TESTS55 Dielectric Voltage-Withstand Test55.1 Each pump shall withstand without electrical breakdown, as a routine production-line test, theapplication of a DC potential or an AC potential at a frequency within the range of 40 - 70 hertz:a) Between the primary wiring, includin

12、g connected components, and accessible dead-metalparts that are likely to become energized andb) Between primary wiring and accessible low-voltage metal parts, including terminals.STANDARD NUMBER: UL 778 -2-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMIS

13、SION FROM UL55.2 The production-line test shall be in accordance with either Condition A or Condition B of Table 55.1.Table 55.1Production-line test conditionsAppliance rating and form Condition A Condition BTestPotential,voltsV ACTestPotentialVDCTime,secondsTestPotential,voltsV ACTestPotentialVDCTi

14、me,seconds105 130 volts, with or without a motorrated 1/2 horsepower (373 W output) orless1000 1400 60 1200 1700 1105 130 volts with motor rated morethan 1/2 horsepower (373 W output)1000 + 2Va1400 +2.8Va60 1200 + 2.4Va1700 +3.4Va1210 600 volts 1000 + 2Vb1400 +2.8Vb60 1200 + 2.4Vb1700 +3.4Vb1aMaximu

15、m marked voltage but no less than 120 volts.bMaximum marked voltage but no less than 240 volts.RATIONALE FOR DECISION:There is a trend that pumps start to use ECM motors (motors with integrated controls). Since UL 778currently requires the use of an AC dielectric test potential, which may produce di

16、electric leakage currentsthrough the capacitors connected to the earth of control AC circuit and trip the dielectric test equipment(false test failure), but the test does not result in an actual breakdown of insulation.This Certification Requirement Decision includes an additional option of using a

17、DC potential as analternative method of conducting the dielectric voltage test for both type and routine (production linetesting). This is a common practice across many standards, including the standard UL 1004-1 for motorsand UL 507 for fans.This alternate method represents the current practice.Cop

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19、. in practically applying therequirements of the standard. They do not represent formal interpretations of the standard underAmerican National Standards Institute (ANSI) processes. UL LLC shall not be responsible to anyone forthe use of or reliance upon Certification Requirement Decisions by anyone.

20、 UL LLC shall not incur anyobligation or liability for damages, including consequential damages, arising out of or in connection withthe use or reliance upon Certification Requirement Decisions. The electronic version of the CertificationRequirement Decision is the current version and previously printed copies may be outdated.This document is published as a service to ULs certification customersSTANDARD NUMBER: UL 778 -3-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULSTANDARD NUMBER: UL 778 -4-No Text on This Page