UL 1090-2020 pdf free download

UL 1090-2020 pdf free download.Electric Snow Movers.
5.20.3 Unless otherwise specified, a printed-wiring board shall have a minimum flame classification of
V-2.
Exception: A pnnted-w:nng board located in a secondary circuit that complies with the requirements for Class 2 or limited voltage/current circuits have a minimum flame Class of HB.
5.21 Semiconductors and small electrical and electronic components
5.21.1 A power switching semiconductor device that is relied upon to provide isolation to ground shall comply with the Standard for Elecincally Isolated Semiconductor Devices. UL 1557.
5.21.2 An optical isolator that is relied upon to provide isolation between primary and secondary circuits or between other circuits as required by this end product standard shall comply with the Standard for Optical Isolators, UL 1577.
5.21.3 Except as otherwise specified in this standard. component requirements are not specified for small electrical parts on printed-wiring boards, including diodes. transistors, resistors, inductors, integrated circuits, and capacitors not directly connected to the supply source.
5.21.4 Where an electronic component is determined to be a critical component during the Abnormal Operation Test. Section 5, in this standard, the circuit shall comply with one or both of the following standards. See Protective Controls (Limiting Controls). Section 2Q4. for the test parameters to be used.
a) The Standard for Tests for Safety-Related Controls Employing Solid-State Devices. UL 991, including Its Follow-Up Program; and as applicable, the Standard for Software in Programmable Components, UL 1998 for controls that rely upon software as a protective component: and/or
b) The Standard for Automatic Electncal Controls for Household and Similar Use: Part 1: General Requirements, UL 60730-1.
5.21.5 A critical component Is a component that performs one or more safety-related functions whose failure results in a condition, such as the risk of fire, electric shock. or injury to persons. in the end product application.
5.2 1.6 A critical component may also be idenhfied using a failure-mode and effect analysis (FMEA) in accordance with the Failure-Mode and Effect Analysis (FMEA) requirements in the Standard for Tests for Safety-Related Controls Employing Solid-State Devices, UL 991.
5.21.7 Portions of a circuit comprised of a microcontroller or other programmable device that performs a back-up, limiting, or other safety function intended to reduce the risk of fire, electric shock, or injury to persons shall comply with the Controls Using Software requirements in the Standard for Automatic Electrical Controls for Household and Similar Use: Part 1: General Requirements, UL 60730-1, Annex H.UL 1090-2020 pdf free download.