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UL 399-2020 pdf free download
UL 399-2020 pdf free download.Drinking Water Coolers.
21.28 Female devices (such as receptacles, appliance couplers, and connectors) that are intended, Of that may be used, to interrupt current, shall be suitably rated for current interruption of the specific type of load, when evaluated with its mating plug or connector.
21.29 Appendix B, Operating and Protective (“Safety Critical’) Control Functions, shall be referenced to determine whether a control function is considered to result in a risk of fire, electrical shock or injury to persons.
21.30 If a control can be used to reduce the risk of fire, electric shock or injury to persons under abnormal operating conditions of the appliance, but a redundant control (of similar or different design) operates to perform the identical function, the circuit shall be evaluated to determine which control will be relied upon as the protective control. The control determined to be the protective control shall cofripty with the protective control requirements in 2i.j. The control determined to be the operating control is not required to comply with the protective control requirements but shall comply with the operating control requirements in 21.24 or with 21.23 and 21.25.
21.31 A thermistor shall comply with Annex J of the Standard for Automatic Electrical Controls — Part 1:
General Requirements, UL 60730-1 or the Standard for Thermistor-Type Devices, UL 1434. The calibration shall be as specified in 2119 if used as part of a water heater temperature protective control or in accordance with 21.21 if used with other controls. If a thermistor is used:
a) To reduce the risk of fire, electric shock or injury to persons under abnormal operating conditions of the appliance, the minimum number of endurance cycles shall be 100,000.
b) In other sensing applications of the appliance, the minimum number of endurance cycles shall be 6,000.
21.32 A protective control as referenced in 21.13(g) or 2451(c) and having a protective electronic circuit:
a) In which electronic disconnection of the circuit could fail, shall have at least two components whose combined operation provides the load disconnection;
b) Shall prevent a risk of fire, electric shock or injury to persons under the relevant fault conditions specified in Section:
C) In which an overcurrent protective device opens during application of any of the fault conditions specified in 83.2, shall utilize an overcurrent protective device complying with the requirements applicable to that component. The fault condition causing the overcurrent protective device to open shall be repeated and the overcurrent protective device shall again open the protective electronic circuit. If the overcurrent protective device complies with IEC 60127-1 Standard for Miniature Fuses; Part 1, Definitions for Mniaturo Fuses and General Requirements for Miniature Fuse-Unks as well as an applicable Part 2, then the protective device shall additionally comply with the FuseLink Test in Section 83.5;UL 399-2020 pdf free download.
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